An experimental system and method for light attenuation characteristics of refrigerant spray-assisted cooling in laser skin surgery

Abstract

The present invention discloses an experimental system and method for light attenuation characteristics of refrigerant spray-assisted cooling in laser skin surgery. The system includes a refrigerant storage tank, a high-pressure hose, a fast-response solenoid valve, a nozzle, a thermometer, a pressure gauge, an electric three-dimensional displacement platform, a rotary table, a laser control box, a laser light source probe, an agar skin phantom, an integrating sphere, a silicon photodetector, a spectrometer, an NI data acquisition card, and a computer. The spray formed by the refrigerant through the nozzle and the laser emitted by the laser light source probe act on the agar skin phantom. Then, the laser enters the integrating sphere and is reflected, and then captured by the spectrometer and the silicon photodetector, and the absorbance and light intensity signals are collected and converted. After being collected by the NI data acquisition card, they are stored in the computer. The present invention fills the blank in the field of laser energy attenuation testing technology in laser skin surgery and can provide an accurate theoretical reference for the selection of refrigerant spray-assisted cooling technical parameters in clinical dermatological treatment.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and particularly relates to a light attenuation characteristic test system and method for refrigerant spray-assisted cooling in laser skin surgery. Background Art

[0002] In the field of laser skin medicine, laser skin surgery based on the selective photothermal effect irradiates skin tissue with a laser of a suitable wavelength band, enabling the laser energy to be maximally absorbed by dermal lesion chromophores (hyperplastic melanin or blood vessels), thereby targeting and removing the lesion chromophores while avoiding thermal damage to surrounding normal tissues. It has the advantages of no bleeding, minimal trauma, few side effects, and remarkable curative effects after surgery, and has become the first choice for clinical treatment of skin diseases such as nevus of Ota and port-wine stains. However, the epidermis of the human body, especially that of yellow race people, also contains normal melanin that strongly absorbs lasers. Before the laser reaches the lesion location in the dermis, it must first pass through the epidermis, often causing side effects such as bleeding, epidermal burns, and hypopigmentation.

[0003] Refrigerant spray cooling (CSC) has the advantages of strong cooling ability, fast evaporation of the surface liquid film, high spatial and temporal selectivity, and non-toxicity to the human body. Supplementary short-pulse (<100 ms) refrigerant spray cooling before laser treatment can effectively prevent epidermal burns caused by competitive absorption of laser energy by epidermal melanin and dermal lesion chromophores (hyperplastic melanin or blood vessels), thereby increasing the allowable laser energy and improving the treatment effect. It has become the golden treatment principle for skin diseases such as nevus of Ota and port-wine stains.

[0004] During refrigerant spray cooling, a large number of droplets impact the skin surface and undergo complex phase change heat transfer and kinetic behavior. Then the droplets converge to form a liquid film, and subsequently the liquid film evaporates and is accompanied by frosting for a long time (about 500 ms). Considering the cooling effect in actual clinical treatment, it is impossible to irradiate the laser after the liquid film and frost layer on the skin surface have completely disappeared. The droplets in flight and the liquid film and frost layer deposited on the skin surface will inevitably absorb and scatter the laser, causing attenuation of the laser energy actually entering the human skin. However, there is currently no mature and complete test system and method for the attenuation of laser energy by spray in clinical practice, which cannot provide accurate theoretical reference for the refrigerant spray-assisted cooling technology in the clinical treatment of skin diseases such as nevus of Ota and port-wine stains. Summary of the Invention

[0005] Aiming at the problems existing in the prior art, the purpose of the present invention is to provide a light attenuation characteristic test system and method for refrigerant spray-assisted cooling in laser skin surgery, which is used to measure the attenuation characteristics of laser energy during the spray process in clinical practice, so as to provide accurate theoretical reference for physicians to optimize cooling and select clinical cooling treatment parameters.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] The present invention first provides an optical attenuation characteristic test system for refrigerant spray-assisted cooling in laser skin surgery. The system includes a spray generating device, an absorbance and light intensity test device, and a data connection line;

[0008] The spray generating device includes a refrigerant storage tank, a high-pressure hose, a fast-response solenoid valve, a nozzle, a thermometer, a pressure gauge, an electric three-dimensional displacement platform, and a rotary table;

[0009] The absorbance and light intensity test device includes a laser control box, a laser source probe, an agar skin phantom, an integrating sphere, a silicon photodetector, a spectrometer, an NI data acquisition card, and a computer.

[0010] The data connection line includes a laser transmission line, a data transmission line, a light intensity signal transmission line, an absorbance signal transmission line, and a wire;

[0011] A thermometer and a pressure gauge are installed above the refrigerant storage tank to monitor the temperature and pressure of the refrigerant in the tank;

[0012] The refrigerant storage tank is connected to the fast-response solenoid valve through a high-pressure hose, and the lower end of the fast-response solenoid valve is connected to the nozzle; the nozzle is also connected to the rotary table, and the rotary table is installed on the Z-axis of the electric three-dimensional displacement platform; the rotary table and the electric three-dimensional displacement platform are respectively used to adjust the angle and height of the nozzle;

[0013] The laser control box is connected to the laser source probe through a laser transmission line, and the laser control box can adjust the energy and spot size of the laser generated by the laser source probe;

[0014] Below the laser source probe are successively an agar skin phantom and an integrating sphere;

[0015] The integrating sphere has openings at both ends, which are respectively an integrating sphere inlet and an integrating sphere outlet; the agar skin phantom is arranged on the integrating sphere inlet; a silicon photodetector and a spectrometer are arranged at the integrating sphere outlet;

[0016] The nozzle is also located above the agar skin phantom, so that the liquid sprayed by the nozzle can be sprayed onto the surface of the agar skin phantom;

[0017] The silicon photodetector is electrically connected to the NI data acquisition card through a light intensity signal transmission line; the spectrometer is electrically connected to the NI data acquisition card through an absorbance signal transmission line;

[0018] The NI data acquisition card is also electrically connected to the fast response solenoid valve through a wire, and is used to control the opening of the fast response solenoid valve;

[0019] The NI data acquisition card is electrically connected to the computer through a data transmission line.

[0020] Preferably, the nozzle is specifically a stainless steel straight tube nozzle; the angle adjustment range of the nozzle is 0 - 360°, and the height adjustment range is 0 - 200 mm; the stainless steel straight tube nozzle includes a mounting screw and a stainless steel capillary tube, and the mounting screw and the stainless steel capillary tube are connected by epoxy resin glue; the length of the stainless steel capillary tube is 40 - 60 mm, and the inner diameter is 0.8 - 1.0 mm.

[0021] Preferably, the agar skin phantom is located directly below the laser light source probe, so that the laser emitted by the laser light source probe is vertically irradiated on the surface of the agar skin phantom; the nozzle is obliquely above the agar skin phantom to avoid spatial interference between the nozzle and the laser emitted by the laser light source probe.

[0022] Preferably, the angle between the axis of the nozzle and the horizontal plane where the agar skin phantom is located is 45 - 60°, and the vertical distance from the nozzle outlet to the upper surface of the agar skin phantom is 30 - 40 mm.

[0023] Preferably, the inner wall of the integrating sphere is coated with a reflective layer, and the reflectivity is not less than 97%.

[0024] Preferably, the agar skin phantom is composed of agar, India ink, and fat emulsion; the size of the agar skin phantom is 20×20×1 mm 3 。

[0025] Preferably, the laser light source probe includes laser probes with wavelengths of 532 nm, 755 nm, and 1064 nm or a xenon light source probe that can emit a continuous wavelength band.

[0026] The present invention also provides a working method for a light attenuation characteristic test system for refrigerant spray assisted cooling in laser skin surgery, and the specific steps are as follows:

[0027] Step 1: First, fill the refrigerant storage tank with refrigerant. After filling, let it stand for a period of time and wait for the readings of the thermometer and pressure gauge to stabilize; avoid local vaporization of the refrigerant in the high-pressure hose, which will cause a reduction in the utilization rate of the working medium and unstable spraying;

[0028] After the values shown on the thermometer and pressure gauge become stable, the refrigerant in the refrigerant storage tank enters the nozzle through the high-pressure hose under the push of pressure. A fast-response solenoid valve is used to precisely control the opening and closing of the nozzle to determine the spray duration. When the nozzle opens, the refrigerant is atomized into a large number of fine droplets through the nozzle, forming a spray and spraying onto the surface of the agar skin phantom. The angle between the axis of the nozzle and the horizontal plane where the agar skin phantom is located is adjusted by a rotating table. The vertical distance from the nozzle outlet to the upper surface of the agar skin phantom is adjusted by an electric three-dimensional displacement platform.

[0029] Step 2: After the laser energy and spot size emitted by the laser light source probe are adjusted by the laser control box, turn on the power switch of the laser control box. The laser is emitted from the laser light source probe and vertically irradiates the agar skin phantom. At the same time, the nozzle opens. Part of the laser is scattered and absorbed by the spray formed by the atomization of the nozzle, and the remaining part of the laser penetrates the agar skin phantom and enters the inside of the integrating sphere through the integrating sphere inlet.

[0030] Step 3: The inner wall of the integrating sphere is coated with a uniform reflective layer with a reflectivity of not less than 97%. After the laser is transmitted through the agar skin phantom and enters the integrating sphere through the integrating sphere inlet, it undergoes multiple reflections. Finally, the light intensity signal is detected by a silicon photodetector placed at the integrating sphere outlet. The silicon photodetector converts the light intensity signal into an electrical signal and transmits it into the NI data acquisition card through the light intensity signal transmission line for signal acquisition.

[0031] A spectrometer is also installed at the integrating sphere outlet position. The spectrometer converts the absorbance signal into an electrical signal and transmits it into the NI data acquisition card through the absorbance signal transmission line for signal acquisition.

[0032] Step 4: In specific operations, the fast-response solenoid valve and the switch power supply of the laser control box are turned on synchronously to ensure that while the spray impacts the surface of the agar skin phantom, the laser irradiates the agar skin phantom synchronously.

[0033] Preferably, in Step 1, the refrigerant is any one of R134a, R404A, R410A, R32, and liquid CO 2 ; The standing for a period of time is 30 - 40 min; The fast-response solenoid valve is used to precisely control the opening and closing of the nozzle, and the opening and closing time of the fast-response solenoid valve is less than 6 ms.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. The present invention provides a test system and method for the light attenuation characteristics of refrigerant spray-assisted cooling in laser skin surgery. A spectrometer and a silicon photodetector are used to detect the absorbance and light intensity signals of the spray, filling the gap in this technical field. Using this system to conduct experiments on the attenuation of laser energy by the spray can provide an accurate theoretical reference for the selection of cooling parameters of the refrigerant spray-assisted cooling technology in the clinical treatment of skin diseases such as nevus of Ota and port-wine stain.

[0036] 2. Due to the easy volatility of the refrigerant, after the refrigerant is injected into the refrigerant storage tank, it automatically stabilizes at its respective saturation pressure after 30 - 40 minutes. This pressure serves as the driving force for the flow and atomization of the refrigerant, eliminating the need for additional liquid supply devices such as pumps and complex pipelines, greatly simplifying the system composition, and making the cooling system safer and more reliable while saving energy.

[0037] 3. The present invention uses a stainless steel straight tube nozzle to atomize the refrigerant to form a spray. The stainless steel straight tube nozzle has a simple structure, low flow resistance, and is inexpensive, convenient for clinical disassembly and replacement.

[0038] 4. The present invention uses an agar skin phantom to replace human skin. On the premise of ensuring similar optical parameters to human skin, it avoids the traumatic collection of patient skin specimens and does not require ethical review for biomedical experimental research.

[0039] 5. The present invention uses a fast-response solenoid valve to precisely control the on / off of the spray. The opening and closing time of the fast-response solenoid valve is less than 6 ms, which can meet the requirements of the ms-level pulse spray time control accuracy in clinical practice. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a schematic diagram of the present invention.

[0041] Figure 2 is a schematic diagram of the stainless steel straight tube nozzle of the present invention.

[0042] Figure 3 is a test result diagram of the absorbance of the surface of the agar skin phantom irradiated by a xenon lamp source that can emit a continuous band of the present invention.

[0043] Figure 4 is a test result diagram of the transmittance of the surface of the agar skin phantom irradiated by a 1064 nm laser of the present invention.

[0044] Description of the reference numerals: 1 - Laser control box, 2 - Laser transmission line, 3 - Laser source probe, 4 - Rotary table, 5 - Electric three-dimensional displacement platform, 6 - Agar skin phantom, 7 - Integrating sphere inlet, 8 - Stainless steel straight tube nozzle, 9 - Quick response solenoid valve, 10 - High-pressure hose, 11 - Data transmission line, 12 - Integrating sphere, 13 - Pressure gauge, 14 - Thermometer, 15 - Computer, 16 - NI data acquisition card, 17 - Light intensity signal transmission line, 18 - Absorbance signal transmission line, 19 - Silicon photodetector, 20 - Spectrometer, 21 - Integrating sphere outlet, 22 - Wire, 23 - Refrigerant storage tank, 24 - Mounting screw, 25 - Stainless steel capillary tube. Detailed implementation mode

[0045] The present invention will be further described below in conjunction with the specific drawings and embodiments.

[0046] Embodiment 1:

[0047] To monitor the attenuation characteristics of laser energy by refrigerant spray in clinical practice, the present invention first provides an optical attenuation characteristic test system for refrigerant spray-assisted cooling in laser skin surgery, as Figure 1 shown, the system includes a spray generating device and an absorbance and light intensity testing device;

[0048] The spray generating device includes a refrigerant storage tank 23, a high-pressure hose 10, a quick response solenoid valve 9, a stainless steel straight tube nozzle 8, a thermometer 14, a pressure gauge 13, an electric three-dimensional displacement platform 5 and a rotary table 4;

[0049] The absorbance and light intensity testing device includes a laser control box 1, a laser source probe 3, an agar skin phantom 6, an integrating sphere 12, a silicon photodetector 19, a spectrometer 20, an NI data acquisition card 16 and a computer 15; the laser source probe 3 includes laser probes with wavelengths of 532 nm, 755 nm and 1064 nm or a xenon light source probe capable of emitting a continuous band.

[0050] Among them, a thermometer 14 and a pressure gauge 13 are installed above the refrigerant storage tank 23 to monitor the temperature and pressure of the refrigerant in the storage tank; the refrigerant storage tank 23 is connected to the quick response solenoid valve 9 through a high-pressure hose 10, and the lower end of the quick response solenoid valve 9 is connected to the stainless steel straight tube nozzle 8; the quick response solenoid valve 9 controls the opening and closing of the stainless steel straight tube nozzle 8;

[0051] The stainless steel straight tube nozzle 8 is also connected to the rotary table 4, and the rotary table 4 is installed on the Z axis of the electric three-dimensional displacement platform 5; the rotary table 4 is used to adjust the angle of the stainless steel straight tube nozzle 8, and the adjustment range is adjusted to 0 - 360°; the electric three-dimensional displacement platform 5 is used to adjust the height of the stainless steel straight tube nozzle 8, and the adjustment range is 0 - 200 mm;

[0052] As shown Figure 2 in FIG. 1, the stainless steel straight tube nozzle 8 used in the present invention includes a mounting screw 24 and a stainless steel capillary 25, and the mounting screw 24 and the stainless steel capillary 25 are connected by epoxy resin glue. In this embodiment, the length of the stainless steel capillary 25 is 60 mm and the inner diameter is 0.8 mm;

[0053] The laser control box 1 is connected to the laser light source probe 3 through a laser transmission line 2, and the laser control box 1 can adjust the energy and wavelength of the laser generated by the laser light source probe 3; in this embodiment, a 1064 nm band laser and a xenon light source capable of emitting a continuous band are used, and the spot diameters are both 6 mm and the power is 0.5 W;

[0054] Below the laser light source probe 3 are an agar skin phantom 6 and an integrating sphere 12 in sequence; among them, the agar skin phantom 6 has optical properties similar to those of human skin, high stability, and is easy to prepare, and its components are agar, Indian ink, and fat emulsion; it can respectively simulate the matrix, absorption components (such as melanin), and scattering components (such as collagen fibers and elastic fibers) in human skin. Its preparation method is well known to those skilled in the art and will not be elaborated here. In this embodiment, the size of the prepared agar skin phantom 6 is 20×20×1 mm 3 ;

[0055] The agar skin phantom 6 is specifically located directly below the laser light source probe 3 so that the laser emitted by the laser light source probe 3 is vertically irradiated on the surface of the agar skin phantom 6; the stainless steel straight tube nozzle 8 is located obliquely above the agar skin phantom 6 to avoid spatial interference between the stainless steel straight tube nozzle 8 and the laser emitted by the laser light source probe 3. Clinically, to avoid spatial interference between the stainless steel straight tube nozzle 8 and the laser emitted by the laser light source probe 3, the laser is vertically irradiated on the skin and the stainless steel straight tube nozzle 8 is placed obliquely; in this embodiment, the angle between the axis of the stainless steel straight tube nozzle 8 and the plane where the agar skin phantom 6 is located is set to 60°, and the vertical distance from the outlet of the stainless steel straight tube nozzle 8 to the upper surface of the agar skin phantom 6 is 30 mm;

[0056] Both ends of the integrating sphere 12 are provided with openings, namely an integrating sphere inlet 7 and an integrating sphere outlet 21; the agar skin phantom 6 is arranged on the integrating sphere inlet 7; a silicon photodetector 19 and a spectrometer 20 are provided at the integrating sphere outlet 21;

[0057] The stainless steel straight tube nozzle 8 is also located above the agar skin phantom 6 so that the liquid ejected from the stainless steel straight tube nozzle 8 can be sprayed onto the surface of the agar skin phantom 6;

[0058] The silicon photodetector 19 is electrically connected to the NI data acquisition card 16 through the light intensity signal transmission line 17; the spectrometer 20 is electrically connected to the NI data acquisition card 16 through the absorbance signal transmission line 18;

[0059] The NI data acquisition card 16 is also electrically connected to the fast response solenoid valve 9 through a wire 22 to control the opening of the fast response solenoid valve 9; the spray time in this embodiment is set to 50 ms;

[0060] The NI data acquisition card 16 is electrically connected to the computer 15 through a data transmission line 11 to store the light intensity and absorbance data collected by the NI data acquisition card 16 in the computer 15;

[0061] The present invention also provides a working method for an optical attenuation characteristic test system for refrigerant spray-assisted cooling in laser skin surgery, which is as follows:

[0062] Step 1: First, test by sequentially filling the refrigerant R134a, R404A, and R32 refrigerant in the refrigerant storage tank 23. After each filling is completed, let it stand for 30 min and wait for the readings of the thermometer and pressure gauge to stabilize; avoid local vaporization of the refrigerant in the high-pressure hose, resulting in reduced utilization rate of the working medium and unstable spraying;

[0063] After the readings of the thermometer 13 and the pressure gauge 14 are stable, the refrigerant in the refrigerant storage tank 23 enters the stainless steel straight pipe nozzle 8 under the push of pressure through the high-pressure hose 10; the fast response solenoid valve 9 is used to precisely control the opening and closing of the stainless steel straight pipe nozzle 8 to determine the spray duration, and the spray duration is determined to be 50 ms; when the stainless steel straight pipe nozzle 8 is opened, the refrigerant is atomized into a large number of fine droplets through the stainless steel straight pipe nozzle 8, forming a spray and spraying onto the surface of the agar skin phantom 6; the angle between the axis of the stainless steel straight pipe nozzle 8 and the horizontal plane where the agar skin phantom 6 is located is adjusted by the rotating table 4, and the angle is set to 60°; the vertical distance from the outlet of the stainless steel straight pipe nozzle 8 to the upper surface of the agar skin phantom 6 is adjusted by the electric three-dimensional displacement platform 5, and the distance is set to 30 mm;

[0064] Step 2: After the laser energy and spot size emitted by the laser light source probe 3 are adjusted by the laser control box 1, turn on the power switch of the laser control box 1, and the laser irradiates the agar skin phantom 6 vertically. Part of the laser is scattered and absorbed by the spray formed by the atomization of the stainless steel straight pipe nozzle 8, and the remaining part of the laser penetrates the agar skin phantom and enters the integrating sphere 12; tests are respectively carried out using a xenon light source with a continuous wavelength band of 370 - 1400 nm and a 1064 nm single-wavelength light source, with a spot diameter of 6 mm and a power of 0.5 W.

[0065] Step 3: The inner wall of the integrating sphere 12 is coated with a uniform reflective layer with a reflectivity of 97%. After the light is transmitted through the agar skin phantom 6 and enters the integrating sphere 12 through the integrating sphere inlet 7, it undergoes multiple reflections. Finally, the silicon photodetector placed at the position of the integrating sphere outlet 21 detects the light intensity signal. After the silicon photodetector 19 converts the light intensity signal into an electrical signal, it is transmitted into the NI data acquisition card 16 through the light intensity signal transmission line 17 for signal acquisition;

[0066] A spectrometer 20 is also installed at the position of the integrating sphere outlet 21. After the spectrometer 20 converts the absorbance signal into an electrical signal, it is transmitted into the NI data acquisition card 16 through the absorbance signal transmission line 18 for signal acquisition;

[0067] During specific operation, the fast-response solenoid valve 9 and the switch power supply of the laser control box 1 are turned on synchronously to ensure that while the spray impacts the surface of the agar skin phantom 6, the laser is synchronously irradiated onto the agar skin phantom 6.

[0068] To study the transient attenuation characteristics of the laser energy during the entire refrigerant spray cooling process (including the formation and development processes of droplets, liquid films, and frosting), in this embodiment, when the laser emitted by the laser light source probe 3 starts to irradiate, the NI data acquisition card 16 synchronously triggers the fast-response solenoid valve 9 to open through the wire 22 to form a 50-ms pulsed spray. The silicon photodetector 19 and the spectrometer 20 are used to collect the voltage data within 2 s from the start of the spray, and after data conversion, it is recorded in the computer 15;

[0069] In this embodiment, refrigerant working fluids R134a, R404A, and R32 are selected for experiments respectively.

[0070] The following gives the typical test results of absorbance and transmittance when the surface of the agar skin phantom 6 is irradiated with a 370 - 1400 nm continuous band xenon light source and a 1064 nm single-wavelength laser respectively in this embodiment, using refrigerants R134a, R404A, and R32, and the spray time is 50 ms;

[0071] Figure 3 For the test results of the absorbance when the surface of the agar skin phantom 6 is irradiated with a xenon light source that can emit a continuous band, Figure 3 In the coordinates, A and λ represent absorbance and wavelength respectively. It can be seen that there are no obvious absorption peaks or valleys in the 370 - 1400 nm band during the refrigerant spray process. The absorbance A decreases rapidly as the wavelength λ increases and then stabilizes in the near-infrared band. In the short wavelength band of visible light, all three refrigerant spray processes have relatively high absorbances, and the absorbances of refrigerants R404A and R32 are smaller compared to R134a.

[0072] Figure 4The results of the light transmittance test using a 1064 nm single-wavelength laser to irradiate the surface of the agar skin phantom 6 Figure 4 In it, LT and t represent the light transmittance and time respectively. It can be seen that compared with the R404A spray, R134a has a stronger attenuation of the 1064 nm laser energy in the initial spray stage (t < 50 ms). When t > 63 ms, the light transmittance of the R32 spray to the 1064 nm laser is as high as 94%, which can meet the requirements of CSC clinical applications.

[0073] In summary, the present invention discloses a light attenuation characteristic test system and method for refrigerant spray-assisted cooling in laser skin surgery. The spectrometer 20 and the silicon photodetector 19 are used to detect the spray absorbance and light intensity signals, filling the gap in this technical field. Using this system to conduct the test experiment on the attenuation of laser energy by the spray can provide an accurate theoretical reference for the selection of cooling parameters of the refrigerant spray-assisted cooling technology in the clinical treatment of skin diseases such as nevus of Ota and port-wine stain.

[0074] Note: The above embodiments are only used to illustrate the present invention and do not limit the technical solutions described in the present invention; therefore, although this specification has described the present invention in detail with reference to the above respective embodiments, those of ordinary skill in the art should understand that the present invention can still be modified or equivalently replaced; and all technical solutions and their improvements that do not depart from the spirit and scope of the present invention shall be covered within the scope of the claims of the present invention.

Claims

1. An experimental system for light attenuation characteristics of refrigerant spray-assisted cooling in laser skin surgery, characterized in that, the system includes a spray generating device, an absorbance and light intensity testing device, and a data connection line; the spray generating device includes a refrigerant storage tank (23), a high-pressure hose (10), a fast-response solenoid valve (9), a nozzle (8), a thermometer (14), a pressure gauge (13), an electric three-dimensional displacement platform (5), and a rotary table (4); the absorbance and light intensity testing device includes a laser control box (1), a laser source probe (3), an agar skin phantom (6), an integrating sphere (12), a silicon photodetector (19), a spectrometer (20), an NI data acquisition card (16), and a computer (15); the data connection line includes a laser transmission line (2), a data transmission line (11), a light intensity signal transmission line (17), an absorbance signal transmission line (18), and a wire (22); a thermometer (14) and a pressure gauge (13) are installed above the refrigerant storage tank (23) to monitor the temperature and pressure of the refrigerant in the storage tank; the refrigerant storage tank (23) is connected to the fast-response solenoid valve (9) through a high-pressure hose (10), and the lower end of the fast-response solenoid valve (9) is connected to the nozzle (8); the nozzle (8) is also connected to the rotary table (4), and the rotary table (4) is installed on the Z-axis of the electric three-dimensional displacement platform (5); the rotary table (4) and the electric three-dimensional displacement platform (5) are respectively used to adjust the angle and height of the nozzle (8); the laser control box (1) is connected to the laser source probe (3) through a laser transmission line (2), and the laser control box (1) can adjust the energy and spot size of the laser generated by the laser source probe (3); below the laser source probe (3) are successively an agar skin phantom (6) and an integrating sphere (12); both ends of the integrating sphere (12) are provided with openings, which are an integrating sphere inlet (7) and an integrating sphere outlet (21) respectively; the agar skin phantom (6) is arranged on the integrating sphere inlet (7); a silicon photodetector (19) and a spectrometer (20) are arranged at the integrating sphere outlet (21); the nozzle (8) is also located above the agar skin phantom (6) so that the liquid ejected from the nozzle (8) can be sprayed onto the surface of the agar skin phantom (6); the silicon photodetector (19) is electrically connected to the NI data acquisition card (16) through a light intensity signal transmission line (17); the spectrometer (20) is electrically connected to the NI data acquisition card (16) through an absorbance signal transmission line (18); the NI data acquisition card (16) is also electrically connected to the fast-response solenoid valve (9) through a wire (22) for controlling the opening of the fast-response solenoid valve (9); the NI data acquisition card (16) is electrically connected to the computer (15) through a data transmission line (11).

2. The experimental system for light attenuation characteristics of refrigerant spray-assisted cooling in laser skin surgery according to claim 1, characterized in that, The nozzle (8) is specifically a stainless steel straight pipe nozzle; the angle adjustment range of the nozzle (8) is 0 - 360°, and the height adjustment range is 0 - 200 mm.

3. A light attenuation characteristic test system for refrigerant spray-assisted cooling in laser skin surgery according to claim 2, characterized in that the stainless steel straight pipe nozzle includes a mounting screw (24) and a stainless steel capillary (25), and the mounting screw (24) and the stainless steel capillary (25) are connected by epoxy resin glue; the length of the stainless steel capillary (25) is 40 - 60 mm, and the inner diameter is 0.8 - 1.0 mm.

4. A light attenuation characteristic test system for refrigerant spray-assisted cooling in laser skin surgery according to claim 1, characterized in that the agar skin phantom (6) is located directly below the laser light source probe (3) so that the laser emitted by the laser light source probe (3) irradiates perpendicularly onto the surface of the agar skin phantom (6); the nozzle (8) is located obliquely above the agar skin phantom (6) to avoid spatial interference between the nozzle (8) and the laser emitted by the laser light source probe (3).

5. A light attenuation characteristic test system for refrigerant spray-assisted cooling in laser skin surgery according to claim 1, characterized in that the angle between the axis of the nozzle (8) and the horizontal plane where the agar skin phantom (6) is located is 45 - 60°, and the vertical distance from the nozzle (8) outlet to the upper surface of the agar skin phantom (6) is 30 - 40 mm.

6. A light attenuation characteristic test system for refrigerant spray-assisted cooling in laser skin surgery according to claim 1, characterized in that the inner wall of the integrating sphere (12) is coated with a reflective layer, and the reflectivity is not less than 97%.

7. A light attenuation characteristic test system for refrigerant spray-assisted cooling in laser skin surgery according to claim 1, characterized in that The agar skin phantom (6) is composed of agar, Indian ink, and fat emulsion; the size of the agar skin phantom (6) is 20×20×1 mm 3 .

8. A light attenuation characteristic test system for refrigerant spray-assisted cooling in laser skin surgery according to claim 1, characterized in that the laser light source probe (3) includes a single-wavelength laser probe or a xenon lamp light source probe that can emit a continuous wavelength band, and the wavelength of the single-wavelength laser probe is 532 nm, 755 nm, and 1064 nm.

9. A working method of a light attenuation characteristic test system for refrigerant spray-assisted cooling in laser skin surgery, characterized in that it includes the following steps: Step 1: First, fill the refrigerant storage tank (23) with refrigerant. After filling, let it stand for a period of time and wait for the readings of the thermometer (14) and the pressure gauge (13) to stabilize; after the readings of the thermometer and the pressure gauge stabilize, the refrigerant in the refrigerant storage tank (23) enters the nozzle (8) under the push of pressure; the quick-response solenoid valve (9) is used to precisely control the opening and closing of the nozzle (8) to determine the spray duration. When the nozzle (8) is opened, the refrigerant is atomized into a large number of fine droplets through the nozzle (8), forming a spray and spraying onto the surface of the agar skin phantom (6); the angle between the axis of the nozzle (8) and the horizontal plane where the agar skin phantom (6) is located is adjusted by the rotary table (4); the vertical distance from the outlet of the nozzle (8) to the upper surface of the agar skin phantom (6) is adjusted by the electric three-dimensional displacement platform (5). Step 2: After the laser energy and spot size emitted by the laser source probe (3) are adjusted by the laser control box (1), turn on the power switch of the laser control box (1), and the laser is emitted from the laser source probe (3) and vertically irradiates the agar skin phantom (6); at the same time, the nozzle (8) is opened, a part of the laser is scattered and absorbed by the spray formed by the atomization of the nozzle (8), and the remaining part of the laser penetrates the agar skin phantom and enters the interior of the integrating sphere (12) through the integrating sphere inlet (7). Step 3: The inner wall of the integrating sphere (12) is coated with a uniform reflective layer with a reflectivity of not less than 97%. After the laser is transmitted through the agar skin phantom (6) and enters the integrating sphere (12) through the integrating sphere inlet (7), it is reflected multiple times, and finally the silicon photodetector (19) placed at the position of the integrating sphere outlet (21) detects the light intensity signal. After the silicon photodetector (19) converts the light intensity signal into an electrical signal, it is transmitted into the NI data acquisition card (16) through the light intensity signal transmission line (17) for signal acquisition. A spectrometer (20) is also installed at the position of the integrating sphere outlet (21). After the spectrometer (20) converts the absorbance signal into an electrical signal, it is transmitted into the NI data acquisition card (16) through the absorbance signal transmission line (18) for signal acquisition. Step 4: During specific operation, the fast response solenoid valve (9) is turned on synchronously with the switch power supply of the laser control box (1) to ensure that while the spray impacts the surface of the agar skin phantom (6), the laser is synchronously irradiated onto the agar skin phantom (6).

10. According to the working method of an optical attenuation characteristic test system for refrigerant spray assisted cooling in laser skin surgery as described in claim 9, characterized in that The refrigerant described in Step 1 is any one of R134a, R404A, R410A, R32 and liquid CO 2 ; the standing for a period of time is 30 to 40 minutes; the passing through the fast response solenoid valve (9) is used to precisely control the opening and closing of the nozzle (8), wherein the opening and closing time of the fast response solenoid valve (9) is less than 6 ms.

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