Temperature range control device and method for multi-wavelength laser intracranial ablation

Abstract

The invention discloses a temperature range control device and method for multi-wavelength laser intracranial ablation, and the device comprises an optical fiber probe, a multi-wavelength laser, a controller and an MRI temperature measurement device, and obtains an optimized ablation width through the mixing of different wavelengths according to the absorption characteristics of biological tissues of different wavelengths. A controller is set to calibrate the temperature rise widths of different-wavelength lasers emitted by a multi-wavelength laser in the corresponding biological tissue in advance according to an MRI temperature measuring device, the controller is used for selecting different-wavelength lasers for mixing according to the temperature rise widths of the different-wavelength lasers in the corresponding biological tissue, and the temperature rise widths of the different-wavelength lasers in the corresponding biological tissue are calculated according to the set width of a biological tissue ablation area. The mixing proportion of the laser of each wavelength is adjusted, and the temperature control range is changed; the laser power is automatically adjusted by the controller to ensure that the temperature rise of the biological tissue is maintained for a specific time, so that the biological tissue is destroyed.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical equipment, and in particular relates to a temperature range control device and method for multi-wavelength laser intracranial ablation. Background Art

[0002] Laser intracranial ablation is a minimally invasive procedure that uses local heat deposition over a few minutes to cause irreversible destruction of pathological tissues to treat diseases such as glioblastoma or epilepsy. The proton resonance frequency (PRF) shift method is used to calculate the MR temperature map and evaluate the thermal damage boundary. The operation is performed under real-time temperature monitoring of magnetic resonance (MR). If the laser power is set too high, it may cause carbonization, dehydration or vaporization of the tissue, and changes in the optical properties of the tissue may lead to inaccurate magnetic resonance temperature measurement. In addition, since the absorption of light by pathological tissue, microcirculation, macroscopic perfusion, and thermal diffusivity all affect the temperature rise process, temperature control in laser intracranial ablation is difficult.

[0003] At present, laser intracranial ablation devices usually use a single wavelength, such as 980nm or 1064nm, and there are no multi-wavelength laser intracranial ablation devices. Due to the single tissue absorption coefficient of 980nm or 1064nm, it is difficult to accurately control the temperature range. 1064nm laser is more suitable for soft tissues with high white matter volume because the laser shows a higher penetration depth in the wavelength range of 1000-1100nm. The advantage of 980nm diode laser is that its wavelength is ideal for water absorption. Considering that the brain is an environment with a high water content, these characteristics make it possible to create faster damage with a significant thermal gradient. However, since the biological tissue absorption characteristics of each laser wavelength are fixed, 1064nm has a small water absorption coefficient, a large penetration depth, and a large ablation area, but it may cause additional damage. 980nm has a large water absorption coefficient, a small penetration depth, and a small ablation area, and there may be incomplete ablation of tumor tissue. For single-wavelength devices, since the absorption coefficient of biological tissue is constant and the downward trend of optical power is consistent, the actual temperature control area does not change, so a single wavelength cannot achieve a change in the temperature control area. Summary of the invention

[0004] In order to solve the problem that the existing technology cannot achieve the change of the temperature control area using a single wavelength, the present invention provides a temperature range control device and method for multi-wavelength laser intracranial ablation to solve the above-mentioned technical defects.

[0005] In a first aspect, the present invention provides a temperature range control device for multi-wavelength laser intracranial ablation, comprising a fiber optic probe, a multi-wavelength laser, a controller, and an MRI temperature measurement device;

[0006] The multi-wavelength laser and the MRI temperature measuring device are both connected to the controller; the multi-wavelength laser is used to output lasers of different wavelengths, and the lasers of different wavelengths are output individually or in any combination, and the power of each wavelength laser is independently adjustable; the optical fiber probe is inserted into the biological tissue and connected to the multi-wavelength laser, and is used to transmit the laser output by the multi-wavelength laser to the diffusion column at the end through the optical fiber; the MRI temperature measuring device is used to perform nuclear magnetic imaging on the biological tissue to generate a three-dimensional image of temperature rise;

[0007] The controller adjusts the power of lasers with different wavelengths of the multi-wavelength laser according to the three-dimensional image of temperature rise.

[0008] Preferably, the optical fiber probe further comprises an outer tube, the diffusion column is arranged inside the outer tube, and the space between the diffusion column and the outer tube is filled with a coolant. The coolant is arranged to achieve heat dissipation of the optical fiber probe.

[0009] Preferably, the optical fiber probe is connected to the multi-wavelength laser via an optical fiber connector, and the optical fiber connector includes an SMA905 connector and an FC connector. The optical fiber probe is provided with different optical fiber interfaces to ensure effective connection with the optical fiber.

[0010] Preferably, the multi-wavelength laser is used to output lasers with wavelengths of 810nm±20nm, 1064nm±20nm, 904±20nm and 980±20nm, and the power of each wavelength laser is above 20W. Different wavelengths have different absorption coefficients. The larger the absorption coefficient, the more concentrated the temperature rise, and the smaller the area affected by the laser; the smaller the absorption coefficient, the larger the range of temperature rise, and the larger the range of temperature rise affected by the laser.

[0011] In a second aspect, the present invention proposes a temperature range control method for multi-wavelength laser intracranial ablation using the above controller, comprising:

[0012] Controlling the multi-wavelength laser to output lasers of different wavelengths, setting the power of the lasers of different wavelengths to a specific value, outputting them for a specific time, and controlling the MRI temperature measuring device to measure the temperature rise change of biological tissues under lasers of different wavelengths, shutting off the multi-wavelength laser when it is recognized that the temperature rise change of the biological tissues is stable, and processing the three-dimensional temperature rise images under lasers of different wavelengths generated by the MRI temperature measuring device to obtain the temperature rise width of lasers of different wavelengths;

[0013] Select the required ablation area width, use the preset proportional coefficient to correct the ablation area width, and obtain the corrected ablation area width; select different wavelength lasers that need to be ablated for mixing, use the optimization algorithm to adjust the optimized mixing proportional coefficients of lasers of different wavelengths, so that the mixed ablation area width is close to the corrected ablation area width, and at the same time control the MRI temperature measuring device to measure the temperature rise change of biological tissue under the mixed wavelength laser, and adjust the power of the corresponding wavelength laser according to the temperature rise change of biological tissue under the mixed wavelength laser; wherein, the sum of the optimized mixing proportional coefficients of lasers of different wavelengths is 1. By mixing different wavelengths, the temperature control range can be changed. For example, when the mixed wavelengths of 1064nm and 980nm, and the power of each wavelength is 0.5W, the width can be controlled between 1064nm and 980nm; and the laser power is automatically adjusted to ensure that the temperature rise of biological tissue is maintained for a specific time, thereby destroying the biological tissue.

[0014] Preferably, the temperature rise of the biological tissue is stabilized at 5-10 degrees.

[0015] Preferably, the required ablation area width is calculated based on the size of the biological tissue. When treating tumor biological tissues, such as brain tumors, doctors need to ensure that the entire tumor body and its possible diffusion areas are completely ablated, which requires that the width of the ablation area covers the actual size of the tumor.

[0016] Preferably, the optimization algorithm is expressed as:

[0017] C1*exp(-τ λ1 *x)+C2*exp(-τ λ2 *x)+C3*exp(-τ λ3 *x)+C n *exp(-τ λn *x);

[0018] Where x represents the distance that the laser propagates in the biological tissue, λ1, λ2, λ3, and λn represent different wavelengths of lasers that need to be ablated, and C1, C2, C3, and C n represents the optimized mixing ratio coefficient corresponding to λ1, λ2, λ3, λn, τ λ1 , τ λ2 , τ λ3 , τ λn Indicates the temperature rise width corresponding to λ1, λ2, λ3, and λn. By setting the initial values ​​of C1, C2, C3, and C4, these values ​​are continuously adjusted to obtain the optimal mixing ratio coefficient.

[0019] Compared with the prior art, the beneficial results of the present invention are:

[0020] An optical fiber probe, a multi-wavelength laser, a controller, and an MRI temperature measuring device are provided, and the optimized ablation width is obtained by mixing different wavelengths according to the absorption characteristics of biological tissues with different wavelengths. The controller is provided to calibrate the temperature rise width of lasers with different wavelengths emitted by the multi-wavelength laser in the corresponding biological tissues in advance according to the MRI temperature measuring device, and the controller is used to select lasers with different wavelengths for mixing according to the temperature rise width of lasers with different wavelengths in the corresponding biological tissues, and the mixing ratio of each wavelength laser is adjusted according to the set width of the biological tissue ablation area to achieve the change of the temperature control range; the controller is used to automatically adjust the laser power to ensure that the temperature rise of the biological tissue is maintained for a specific time, thereby destroying the biological tissue. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated into and constitute a part of this specification. The accompanying drawings illustrate the embodiments and are used together with the description to explain the principles of the present invention. It will be easy to recognize other embodiments and many expected advantages of the embodiments because they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale with each other. The same reference numerals refer to corresponding similar parts.

[0022] Figure 1 This is a schematic structural diagram of a temperature range control device for multi-wavelength laser intracranial ablation according to an embodiment of the present invention;

[0023] Figure 2 The optical power attenuation ratio and distance relationship diagram of the single-wavelength lasers of 810nm, 904nm, 980nm and 1064nm in biological tissues in the embodiments of the present invention are shown respectively;

[0024] Figure 3 The diagram is a relationship between the optical power attenuation ratio and distance of a 980nm single-wavelength laser with a power of 1W and 2W and a 1064nm single-wavelength laser with a power of 1W in biological tissues according to an embodiment of the present invention;

[0025] Figure 4 The diagrams are the relationship between the optical power attenuation ratio and the distance in biological tissue of the 1064nm and 980nm single wavelength lasers and the mixed 1064nm and 980nm wavelength lasers according to the embodiments of the present invention;

[0026] Figure 5 Schematic diagram of the flow chart of the temperature range control method for multi-wavelength laser intracranial ablation according to an embodiment of the present invention.

[0027] The meanings of the numbers in the figure are: optical fiber probe 01, optical fiber 011, diffusion column 012, outer tube 013, multi-wavelength laser 02, controller 03, MRI temperature measurement device 04. DETAILED DESCRIPTION

[0028] The present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It should also be noted that, for ease of description, only the parts related to the relevant invention are shown in the accompanying drawings.

[0029] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0030] This embodiment discloses a temperature range control device for multi-wavelength laser intracranial ablation. Figure 1 As shown, the device includes an optical fiber probe 01, a multi-wavelength laser 02, a controller 03 and an MRI temperature measurement device 04;

[0031] The multi-wavelength laser 02 and the MRI temperature measuring device 04 are both connected to the controller 03; the multi-wavelength laser 02 is used to output lasers of different wavelengths, and the lasers of different wavelengths are output individually or in any combination, and the power of each wavelength laser is independently adjustable; the optical fiber probe 01 is inserted into the biological tissue and connected to the multi-wavelength laser 02, and is used to transmit the laser output by the multi-wavelength laser 02 to the diffusion column 012 at the end through the optical fiber 011; the MRI temperature measuring device 04 is used to perform nuclear magnetic imaging on the biological tissue to generate a three-dimensional image of temperature rise;

[0032] The controller 03 adjusts the power of lasers of different wavelengths of the multi-wavelength laser 02 according to the three-dimensional temperature rise image.

[0033] Specifically, according to the size of the biological tissue absorption coefficient of different wavelengths and the maturity of the laser, the multi-wavelength laser 02 is set to output lasers with wavelengths of 810nm±20nm, 1064nm±20nm, 904±20nm and 980±20nm, and the power of each wavelength laser is above 20W. Different wavelengths have different absorption coefficients. The larger the absorption coefficient, the more concentrated the temperature rise, and the smaller the area affected by the laser; the smaller the absorption coefficient, the larger the range of temperature rise, and the larger the range of temperature rise affected by the laser. Through the combination of different wavelengths, the range of temperature rise can be controlled.

[0034] Specifically, the optical fiber probe 01 is composed of an optical fiber 011, a diffusion column 012 and an outer tube 013, and is connected to the multi-wavelength laser 02 through an optical fiber connector, and the laser is diffused by the diffusion column 012, wherein the optical fiber connector includes an SMA905 connector and an FC connector. The diffusion column 011 is arranged inside the outer tube 012, and the space between the diffusion column 011 and the outer tube 012 is filled with a coolant. The heat dissipation of the optical fiber probe 01 is achieved by setting the coolant. The optical fiber probe 01 is inserted into the biological tissue, and the biological tissue absorbs the light energy and converts it into heat, causing the temperature of the biological tissue to rise, thereby achieving the purpose of destroying the biological tissue.

[0035] Specifically, the MRI temperature measuring device 04 performs nuclear magnetic imaging on biological tissues, and the controller 03 receives the temperature rise image generated by the MRI temperature measuring device 04, and adjusts the power of lasers of different wavelengths of the multi-wavelength laser 02 in real time according to the temperature of the biological tissue, so as to realize the temperature rise control of the biological tissue. The controller 03 has the following functions: 1) The controller 03 can select the laser wavelengths to be mixed, set the mixing ratio coefficient, and set the total power of the laser; 2) The controller 03 reads the temperature rise image generated by the MRI temperature measuring tissue, obtains the temperature profile, and uses the temperature rise image to calculate the thermodynamic coefficient and the width of the temperature rise area; 3) The controller 03 calculates the mixing ratio of each wavelength according to the set temperature rise area, and the setting of the temperature rise area is determined by the size of the biological tissue; 4) The controller 03 automatically adjusts the laser power to ensure that the temperature rise of the biological tissue is maintained for a specific time, thereby destroying the biological tissue.

[0036] Optionally, the biological tissue mentioned above is brain tumor tissue.

[0037] It should be noted that the transmission of laser in biological tissue is affected by the scattering and absorption of biological tissue. The greater the absorption coefficient, the greater the attenuation of the laser. Scattering also affects laser attenuation. The greater the scattering coefficient, the longer the path that the photon takes at the same straight-line distance. The longer the path, the greater the attenuation. According to the light diffusion equation of biological tissue, the attenuation of the laser is determined by the effective attenuation coefficient:

[0038]

[0039] The light absorbing substances of brain tumor tissue are mainly composed of oxygenated hemoglobin, deoxygenated hemoglobin, water, and fat. According to the literature, the volume ratio coefficient of water is 0.75; the volume ratio coefficient of fat is 0.2; the content of hemoglobin is about 80μmol / L, and the blood oxygen saturation of hemoglobin is 62.5%. According to the formula

[0040] μ a =C HbT ·StO2·e+C HbT ·(1-StO2)·e+frac water +fracwater ·

[0041] It can be obtained that the absorption coefficients corresponding to the lasers with wavelengths of 810nm±20nm, 1064nm±20nm, 904±20nm and 980±20nm are 0.1650, 0.1800, 0.2541 and 0.4801 respectively. It can be seen that the longer the wavelength, the smaller the scattering of laser in biological tissue. According to the literature, a and b are respectively

[0042]

[0043] The scattering coefficients corresponding to the laser wavelengths of 810nm±20nm, 1064nm±20nm, 904±20nm and 980±20nm are 9.6997, 6.4428, 8.2268 and 7.2886.

[0044] Using the formula, the effective attenuation coefficients are 2.2096, 1.8911, 2.5428, and 3.3449.

[0045] In the one-dimensional model, the optical power attenuation is

[0046] I=I0·exp(-μ eff abs(x)

[0047] refer to Figure 2 , Figure 2 Graph showing the relationship between the optical power attenuation ratio and distance of the 810nm, 904nm, 980nm and 1064nm single wavelength lasers in biological tissues according to an embodiment of the present invention.

[0048] When the optical power decays to the peak power exp(-1), it is the temperature control range of the laser. When the ablation area is less than or equal to the temperature control range of the laser, the temperature gradient decreases rapidly due to the rapid decrease of the optical power gradient, and the temperature outside the ablation area decreases rapidly, so the additional thermal damage is small. However, when the ablation area is much larger than the temperature control range of the laser, the optical power gradient decreases slowly, and the temperature outside the ablation area and the temperature within the ablation area tend to be the same, resulting in large additional thermal damage.

[0049] refer to Figure 3 , Figure 3The optical power attenuation ratio and distance relationship diagram of the 980nm single-wavelength laser with a power of 1W and 2W and the 1064nm single-wavelength laser with a power of 1W in the biological tissue of the embodiment of the present invention respectively show that for single-wavelength devices such as 1064nm and 980nm wavelength lasers with a power of 1W, since the absorption coefficient of biological tissue is certain, the downward trend of optical power is consistent, so the actual temperature control area does not change. By increasing the power of the 980nm wavelength laser to 2W, the area of ​​thermal damage can be expanded, but the peak power is higher and the additional damage increases. From the above analysis, a single wavelength cannot achieve changes in the temperature control area.

[0050] Therefore, the present application can achieve the change of the temperature control range by mixing different wavelengths, referring to Figure 4 , Figure 4 The diagrams are the relationship between the optical power attenuation ratio and distance of the 1064nm and 980nm single wavelength lasers and the mixed 1064nm and 980nm wavelength lasers in the biological tissues according to the embodiments of the present invention. Figure 4 When a mixed wavelength of 1064nm and 980nm is used and the power of each wavelength is 0.5W, it can be found that the control width is between 1064nm and 980nm.

[0051] On the other hand, based on the fact that mixed wavelength lasers can control the temperature range, the present application proposes a temperature range control method for multi-wavelength laser intracranial ablation using the above-mentioned controller 03, which includes three stages, namely single wavelength calibration, wavelength optimization mixing, and calibration of mixed wavelength light source.

[0052] Single wavelength calibration: control the multi-wavelength laser 02 to output lasers of different wavelengths, set the power of lasers of different wavelengths to a specific value (such as 3 watts), and output for a specific time (such as 20 seconds), and at the same time control the MRI temperature measuring device 04 to measure the temperature rise change of the tissue under lasers of different wavelengths, and turn off the multi-wavelength laser 02 when the temperature rise change of the tissue is stable. It is appropriate to increase the temperature by 5-10 degrees to ensure that the biological tissue is not damaged; process the three-dimensional temperature rise images generated by the MRI temperature measuring device 04 under lasers of different wavelengths to obtain the temperature rise width τ of lasers of different wavelengths λ1 , τ λ2 , τ λ3 , τ λn ;

[0053] Reference for steps to optimize wavelength mixing and calibrate mixed wavelength light sources Figure 5 ,include:

[0054] Ablation area width: Select the required ablation area width τ set ;

[0055] Correction coefficient: Use the preset proportional coefficient k to adjust the ablation area width τ set Make corrections to obtain the corrected ablation area width k*τ set ;

[0056] Wavelength selection: Select different wavelength lasers (λ1, λ2, λ3, λ4) that need to be ablated and mix them to obtain the width τ of the ablation area after mixing mix ;

[0057] Wavelength mixing ratio coefficient: Use the optimization algorithm to adjust the optimized mixing ratio coefficients (C1, C2, C3, C4) of different wavelength lasers (λ1, λ2, λ3, λ4) so ​​that the width of the ablation area after mixing is τ mix Close to the corrected ablation area width k*τ set ,

[0058] Specifically, the initial value C1=C2=C3=C4=1 / 4 is set, and the width τ of the mixed ablation area is calculated. mix ; The optimization algorithm is expressed as:

[0059] C1*exp(-τ λ1 *x)+C2*exp(-τ λ2 *x)+C3*exp(-τ λ3 *x)+C n *exp(-τ λn *x);

[0060] Where x represents the distance that the laser propagates in the biological tissue, λ1, λ2, λ3, and λn represent different wavelengths of lasers that need to be ablated, and C1, C2, C3, and C n represents the optimized mixing ratio coefficient corresponding to λ1, λ2, λ3, λn, τ λ1 , τ λ2 , τ λ3 , τ λn Indicates the temperature rise width corresponding to λ1, λ2, λ3, and λn. C1, C2, C3, and C4 are continuously adjusted to obtain the optimal mixing ratio coefficient. At the same time, the MRI temperature measuring device 04 is controlled to measure the temperature rise change of the tissue under the mixed wavelength laser, and the power of the corresponding wavelength laser is adjusted according to the temperature rise change of the tissue under the mixed wavelength laser; wherein the sum of the optimized mixing ratio coefficients of lasers of different wavelengths is 1. By mixing different wavelengths, the temperature control range can be changed. For example, when the wavelengths of 1064nm and 980 are mixed and the power of each wavelength is 0.5W, the width can be controlled between 1064nm and 980nm; and the laser power is automatically adjusted to ensure that the temperature rise of the tissue is maintained for a specific time, thereby destroying the tissue.

[0061] The technical solution of the present application sets up an optical fiber probe 01, a multi-wavelength laser 02, a controller 03 and an MRI temperature measuring device 04, and obtains an optimized ablation width by mixing different wavelengths according to the absorption characteristics of biological tissues with different wavelengths. The controller 03 is set to calibrate the temperature rise width of different wavelengths of laser light emitted by the multi-wavelength laser 02 in the corresponding biological tissue in advance according to the MRI temperature measuring device 04, and the controller 03 is used to select different wavelengths of laser light for mixing according to the temperature rise width of different wavelengths of laser light in the corresponding biological tissue, and the mixing ratio of each wavelength of laser light is adjusted according to the set width of the biological tissue ablation area to achieve a change in the temperature control range; the controller 03 is used to automatically adjust the laser power to ensure that the temperature rise of the biological tissue is maintained for a specific time, thereby destroying the biological tissue.

[0062] The above description is only a preferred embodiment of the present invention and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present invention is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above inventive concept. For example, the above features are replaced with the technical features with similar functions disclosed in the present invention (but not limited to) to form a technical solution.

Claims

1. A temperature range control device for multi-wavelength laser intracranial ablation, characterized in that: It includes a fiber optic probe, a multi-wavelength laser, a controller, and an MRI temperature measurement device; The multi-wavelength laser and the MRI temperature measuring device are both connected to the controller; the multi-wavelength laser is used to output lasers of different wavelengths, and the lasers of different wavelengths are output individually or in any combination, and the power of each wavelength laser is independently adjustable; the optical fiber probe is inserted into the biological tissue and connected to the multi-wavelength laser, and is used to transmit the laser output by the multi-wavelength laser to the diffusion column at the end through the optical fiber; the MRI temperature measuring device is used to perform nuclear magnetic imaging on the biological tissue to generate a three-dimensional image of temperature rise; The controller adjusts the power of lasers of different wavelengths of the multi-wavelength laser respectively according to the temperature rise three-dimensional image.

2. The device according to claim 1, characterized in that The optical fiber probe further comprises an outer tube, the diffusion column is arranged inside the outer tube, and a cooling liquid is filled between the diffusion column and the outer tube.

3. The device according to claim 2, characterized in that The optical fiber probe is connected to the multi-wavelength laser via an optical fiber connector, and the optical fiber connector includes an SMA905 connector and an FC connector.

4. The device according to claim 1, characterized in that The multi-wavelength laser is used to output lasers with wavelengths of 810nm±20nm, 1064nm±20nm, 904±20nm and 980±20nm, and the power of each wavelength laser is above 20W.

5. A method for controlling the temperature range of multi-wavelength laser intracranial ablation, using the controller according to any one of claims 1 to 4, characterized in that: include: Controlling the multi-wavelength laser to output lasers of different wavelengths, setting the power of the lasers of different wavelengths to a specific value, and outputting them for a specific time, while controlling the MRI temperature measuring device to measure the temperature rise change of the biological tissue under the lasers of different wavelengths, turning off the multi-wavelength laser when it is recognized that the temperature rise change of the biological tissue is stable, and processing the three-dimensional temperature rise images generated by the MRI temperature measuring device under the lasers of different wavelengths to obtain the temperature rise width of the lasers of different wavelengths; Select the required ablation area width, correct the ablation area width using a preset proportional coefficient, and obtain the corrected ablation area width; select different wavelength lasers that need to be ablated for mixing, and use an optimization algorithm to adjust the optimized mixing proportional coefficients of lasers of different wavelengths so that the mixed ablation area width is close to the corrected ablation area width, and at the same time control the MRI temperature measuring device to measure the temperature rise change of the biological tissue under the mixed wavelength laser, and adjust the power of the corresponding wavelength laser according to the temperature rise change of the biological tissue under the mixed wavelength laser; wherein the sum of the optimized mixing proportional coefficients of lasers of different wavelengths is 1.

6. The method according to claim 5, characterized in that The temperature rise of the biological tissue is stably 5-10 degrees.

7. The method according to claim 5, characterized in that The required ablation area width is calculated and obtained according to the size of the biological tissue.

8. The method according to claim 5, characterized in that The optimization algorithm is expressed as: C1*exp(-τ λ1 *x)+C2*exp(-τ λ2 *x)+C3*exp(-τ λ3 *x)+C n *exp(-τ λn *x); Wherein, x represents the distance that the laser propagates in the biological tissue, λ1, λ2, λ3, and λn represent the different wavelengths of lasers that need to be ablated, and C1, C2, C3, and C n represents the optimized mixing ratio coefficient corresponding to λ1, λ2, λ3, λn, τ λ1 , τ λ2 , τ λ3 , τ λn Indicates the temperature rise width corresponding to λ1, λ2, λ3, and λn.

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