Q-switched thulium laser treatment system for thrombus ablation

Abstract

The application provides a Q-switched thulium laser treatment system for thrombus ablation. The system comprises a thulium laser generating device for generating Q-switched thulium laser, and a thrombus ablation assembly comprising a thrombus ablation catheter and an optical fiber. The optical fiber is arranged in the thrombus ablation catheter, and is used for obtaining the Q-switched thulium laser and emitting the Q-switched thulium laser towards a thrombus in a blood vessel. The ablation effect on the thrombus can be ensured, and the damage to the human body is small.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of medical surgical laser equipment, and particularly relates to a Q-switched thulium laser treatment system for thrombus ablation. BACKGROUND

[0002] Thrombus is the main cause and complication of cardiovascular disease, which can cause myocardial infarction, acute ischemic stroke or venous thromboembolism. When fibrin, red blood cells, platelets and white blood cells and other tissues deposit and coagulate in the blood vessels, thrombus is formed, which destroys blood flow. Different thrombi in different parts of the human body, different formation rates and different areas differ in structure, but all cause damage to the body. At present, the morbidity of thrombus is very high, and a quick, effective and safe thrombus ablation technique is a favorable means to maintain human health and reduce social burden.

[0003] Laser thrombolysis is closely related to wavelength, pulse width and power. Pulsed laser has the advantages of high intensity, high precision, little damage to surrounding tissues, few postoperative complications, etc. Therefore, it is widely used in clinical medicine. Different biological tissues have the characteristics of absorbing different specific wavelengths of laser. The mechanism of laser thrombolysis mainly includes photochemical effect, photothermal effect and photomechanical effect. The specific wavelength of laser is used to act on thrombus, to destroy the molecular bonds of biological tissues or to ablate tissues directly through thermal effect, so as to achieve the purpose of thrombolysis, which is the mechanism of laser thrombolysis. The biological tissue can effectively absorb laser, which can more easily achieve precise, effective and safe thrombolysis effect.

[0004] The existing thrombus ablation device has unsatisfactory treatment effect, and it is urgent to provide a treatment system based on laser thrombolysis. SUMMARY

[0005] The present application provides a Q-switched thulium laser treatment system for thrombus ablation, which can ensure the thrombus ablation effect and also ensure less damage to the human body. It comprises:

[0006] A thulium laser generating device for generating Q-switched thulium laser;

[0007] A thrombus ablation assembly comprising a thrombus ablation catheter and an optical fiber; the optical fiber is arranged in the thrombus ablation catheter, used for obtaining Q-switched thulium laser and emitting the Q-switched thulium laser towards thrombus in the blood vessel.

[0008] Optionally, the pulse width of the Q-switched thulium laser is nanosecond level, and the value range is 30-1000 ns.

[0009] Optionally, the peak power of the Q-switched thulium laser is 0-20 kW, and the average power of the Q-switched thulium laser is 0-30 W.

[0010] Optionally, the repetition frequency of the Q-switched thulium laser is 200 Hz-200 kHz.

[0011] Optionally, the diameter of the optical fiber is 50-600 μm.

[0012] Optionally, the thulium laser generating device adopts a master oscillator power amplifier structure, and comprises:

[0013] a seed light generating assembly and a laser amplification assembly connected in sequence by the thulium-doped optical fiber;

[0014] The seed light generating assembly is configured to generate seed light of the thulium laser, and comprises:

[0015] The first grating and the second grating are arranged in sequence between the acousto-optic modulation device, the first laser and the first pump light stripping unit, and the first laser isolation unit arranged after the second grating, and the first laser isolation unit is configured to control unidirectional transmission of the seed light.

[0016] The laser amplification assembly is configured to amplify the seed light to form the thulium laser meeting the requirements, and comprises a plurality of second lasers, a second pump light stripping unit and a second laser isolation unit coupled with the thulium-doped optical fiber, and the second laser isolation unit is configured to control unidirectional transmission of the thulium laser.

[0017] Optionally, the thrombus ablation catheter comprises a first channel, a second channel and a third channel; the optical fiber and the positioning member are arranged in the first channel and the second channel respectively, and the third channel is configured to pass the ablated thrombus.

[0018] Optionally, the first channel is arranged at the center of the thrombus ablation catheter, the third channel is arranged at the edge of the thrombus ablation catheter, and the third channel surrounds the first channel and the second channel.

[0019] Optionally, the thrombus ablation assembly further comprises:

[0020] The thrombus suction unit is in communication with the third channel of the thrombus ablation catheter and is configured to suck the thrombus.

[0021] Optionally, the thrombus suction unit comprises a negative pressure suction device.

[0022] The technical scheme provided by the application has the following beneficial effects:

[0023] The application provides a Q-switched thulium laser treatment system for thrombus ablation, comprising a thulium laser generating device and a thrombus ablation assembly, and the thrombus ablation assembly comprises a thrombus ablation catheter and an optical fiber. The thulium laser generating device is used for generating a Q-switched thulium laser, and the thrombus ablation assembly is used for sending the Q-switched thulium laser to a thrombus in a blood vessel of a patient through the optical fiber. The optical fiber is arranged in the thrombus ablation catheter, and the optical fiber can be moved to the thrombus by controlling the movement of the thrombus ablation catheter. In the application, a nanosecond fiber thulium laser (Q-switched thulium laser) with high peak power is formed and output to a body cavity environment for surgical treatment. The high peak power of the Q-switched thulium laser can better realize thermal ablation and thermal blasting, and the narrow pulse width of the Q-switched thulium laser can effectively prolong the thermal relaxation time of the tissue and avoid the temperature around the treatment point from rising to a degree that damages normal tissues. By using the Q-switched thulium laser for thrombus ablation, the thrombus ablation effect can be ensured, and the laser can be prevented from damaging the human body. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can also be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0025] Figure 1 A structural schematic diagram of a Q-switched thulium laser treatment system for thrombus ablation provided by the application is shown in the figure.

[0026] Figure 2 A structural schematic diagram of another Q-switched thulium laser treatment system for thrombus ablation provided by the application is shown in the figure.

[0027] Figure 3 A structural schematic diagram of a thrombus ablation catheter provided by the embodiment is shown in the figure.

[0028] The reference signs are as follows:

[0029] 1: thulium laser generating device; 11: seed light generating assembly; 111: first grating; 112: acousto-optic modulation device; 113: first laser; 114: first beam combiner; 115: first pump light stripping unit; 116: second grating; 117: first laser isolation unit; 12: laser amplification assembly; 121: second laser; 122: second beam combiner; 123: second pump light stripping unit; 124: second laser isolation unit; 13: thulium-doped optical fiber;

[0030] 2: Thrombus ablation assembly; 21: Thrombus ablation catheter; 211: First channel; 212: Second channel; 213: Third channel; 22: Optical fiber; 23: Positioning member; 24: Thrombus suction unit. DETAILED DESCRIPTION

[0031] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below in combination with the drawings in the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the protection scope of the present application.

[0032] Before formally introducing the technical solutions of the present application, the main inventive concept of the present application will be briefly introduced:

[0033] First, about thulium laser.

[0034] The existing thulium laser is usually used for crushing stones in the medical field, and the present application is to use thulium laser for thrombus ablation. The basic principle is as follows: the wavelength of thulium laser is in the strong absorption peak of water, which can be completely absorbed by water in a very short distance, can better vaporize and cut the tissue, and has higher cutting precision. When the thulium laser is close to the water-rich tissue, precise ablation can be achieved, and it will not further transmit and diffuse; when the thulium laser is far away from the target tissue in the liquid environment, the water and other liquid media absorb the laser energy to form a cavity, generate a strong shock wave and high-speed microjet, and this photo-mechanical effect can also effectively remove the thrombus and other plaques, and the clearing effect on the plaques is more significant. However, because the thulium laser energy is completely absorbed by water in a very short distance, it is easy to cause local temperature rise too fast, resulting in unnecessary thermal damage.

[0035] Second, Q-switching operation is performed on the thulium laser.

[0036] The micro-explosion effect of the Q-switched pulse thulium laser with instantaneous extremely high power can be generated on the biological tissue, the advantages of the photo-thermal effect and the photo-mechanical effect are combined, the impact force and the thermal influence area are concentrated in the target area, and the damage of the shock wave and the thermal diffusion to the surrounding tissue is greatly reduced. Moreover, the beam quality and the collimation characteristics of the Q-switched thulium laser are good, and the thulium laser has high energy density and low loss, so the thulium laser is an ideal choice for laser medical treatment. In the application, the self-developed Q-switching light path is used to realize the output of the thulium laser with ultra-short pulse width and ultra-high peak power. In the implementation process, the same output energy can be concentrated in a shorter time, so that the heat relaxation time in unit time is more sufficient, and the pulse shaping technology is combined to greatly reduce the additional thermal effect of the thulium laser. (That is, first, the Q-switching is used to realize the output of the thulium laser with ultra-short pulse width and ultra-high peak power; second, the high peak power and short pulse width are beneficial to reduce the long-time heat accumulation, and the inherent disadvantage of the traditional thulium laser in thrombus ablation is compensated.)

[0037] Based on the above principle, the application forms a Q-switched thulium laser treatment system for thrombus ablation, so as to ensure the ablation effect of the thrombus and prevent the thulium laser from causing damage to the human body. The specific technical scheme can be seen in the following embodiments.

[0038] Figure 1 A structure diagram of a Q-switched thulium laser treatment system for thrombus ablation provided by the application is shown in Figure 1 , which comprises:

[0039] A thulium laser generating device 1 is used to generate a Q-switched thulium laser.

[0040] A thrombus ablation assembly 2 comprises a thrombus ablation catheter 21, an optical fiber 22 and a positioning member (shown in Figure 3 ).

[0041] The thrombus ablation catheter 21 comprises a first channel, a second channel and a third channel; the optical fiber and the positioning member are arranged in the first channel and the second channel respectively, and the third channel is used for passing the ablated thrombus.

[0042] The application provides a Q-switched thulium laser treatment system for thrombus ablation, which comprises a thulium laser generating device and a thrombus ablation assembly, and the thrombus ablation assembly comprises a thrombus ablation catheter and an optical fiber. The thulium laser generating device is used for generating Q-switched thulium laser, and the thrombus ablation assembly is used for sending the Q-switched thulium laser to a thrombus in a blood vessel of a patient through the optical fiber. The optical fiber is arranged in the thrombus ablation catheter, and the optical fiber can be moved to the thrombus by controlling the movement of the thrombus ablation catheter. In the application, a nanosecond fiber thulium laser (Q-switched thulium laser) with high peak power is formed and output to a body cavity environment for surgical treatment. The high peak power of the Q-switched thulium laser can better realize thermal ablation and thermal blasting, and the narrow pulse width of the Q-switched thulium laser can effectively prolong the thermal relaxation time of the tissue and avoid the temperature around the treatment point from rising to a degree that damages normal tissue. The Q-switched thulium laser is used for thrombus ablation, so that the thrombus ablation effect can be ensured, and the laser can be prevented from damaging the human body.

[0043] Figure 2 Another structure schematic diagram of the Q-switched thulium laser treatment system for thrombus ablation provided by the application is provided. Figure 2 The thulium laser generating device 1 adopts a master oscillator power amplifier structure and comprises:

[0044] A seed light generating assembly 11 and a laser amplification assembly 12 are sequentially connected through a thulium-doped optical fiber 13.

[0045] The seed light generating assembly 11 is used for generating seed light of the thulium laser and comprises:

[0046] A first grating 111 and a second grating 116 are sequentially arranged between an acousto-optic modulation device 112, a first laser 113 and a first pump light stripping unit 115 and a first laser isolation unit 117 arranged after the second grating, and the first laser isolation unit is used for controlling unidirectional transmission of the seed light.

[0047] The laser amplification assembly 12 is used for amplifying the seed light to form required thulium laser and comprises a plurality of second lasers 121, a second pump light stripping unit 123 and a second laser isolation unit 124 coupled with the thulium-doped optical fiber, and the second laser isolation unit 123 is used for controlling unidirectional transmission 21 of the thulium laser.

[0048] In the embodiment, the first laser 113 is coupled into the thulium-doped optical fiber 13 through a first beam combiner 114, and the second laser 121 is coupled into the thulium-doped optical fiber 13 through a second beam combiner 122.

[0049] In the embodiment, the first laser 113 and the second laser 121 are pump sources and comprise semiconductor lasers.

[0050] In the embodiment, a pulse signal generator can be used to provide an input signal for the acousto-optic modulation device 112.

[0051] In the embodiment, the thulium-doped fiber 13 is a double-clad thulium-doped fiber.

[0052] In the embodiment, the first pump light stripping unit 115 and the second pump light stripping unit 123 include a cladding light stripper.

[0053] In the embodiment, the first laser isolation unit 117 and the second laser isolation unit 124 are isolators.

[0054] In the embodiment, the seed source of the acousto-optic Q-switched laser mainly includes a first grating (i.e., a high-reflectivity grating), an acousto-optic modulation device, a first laser (i.e., a semiconductor laser), a first beam combiner, a double-clad thulium-doped fiber, a cladding light stripper, and a second grating (i.e., a low-reflectivity grating). The acousto-optic modulation device with a fiber pigtail at both ends is inserted into a cavity and used as an active Q-switching device. A pulse signal generator is used to provide a driving signal for the acousto-optic modulation device, so that the frequency and duty cycle of the laser can be conveniently adjusted. A 30 W semiconductor laser (103) is used as a pump source. The pump light is coupled into a double-clad thulium-doped fiber with a core diameter of 10 μm and a cladding diameter of 130 μm through a (1+1) *1 beam combiner. A pair of high-reflectivity and low-reflectivity gratings with a center wavelength of 1940 nm are used to form a resonant cavity to oscillate and select the output wavelength of the laser. A cladding light stripper is used to strip the residual pump light. After the laser is output from the low-reflectivity grating, the first laser isolation unit (i.e., an isolator) is used to prevent the return light from causing adverse effects on the optical path and ensure the unidirectional propagation of the light beam.

[0055] The amplification stage (i.e., a laser amplification assembly) uses two 35 W 793 nm semiconductor lasers. The lasers are coupled into a double-clad thulium-doped fiber with a core diameter of 25 μm and a cladding diameter of 250 μm through a (2+1) *1 beam combiner to amplify the seed light. Then, the residual pump light is stripped through the second laser stripping unit (i.e., a cladding light stripper). Finally, the nanosecond pulse thulium laser with adjustable timing is output through the second laser isolation unit (i.e., an isolator). The output light has a center wavelength of 1940 nm.

[0056] In the embodiment, the pulse width of the Q-switched thulium laser is in the nanosecond range and ranges from 30 ns to 1000 ns.

[0057] For example, the pulse width of the Q-switched thulium laser can be 500 ns.

[0058] In the embodiment, the Q-switched thulium laser has a pulse width of nanoseconds, and the laser single pulse duration is one order of magnitude less than the laser-induced bubble annihilation time (the latter is microsecond level), which can ensure that the laser will not penetrate the liquid layer to harm the human body when working at a certain distance.

[0059] In the embodiment, the peak power of the Q-switched thulium laser is 0-20 kW, and the average power of the Q-switched thulium laser is 0-30 W.

[0060] Exemplarily, the peak power of the Q-switched thulium laser is 50 kW, and the average power of the Q-switched thulium laser is 20 W.

[0061] In the embodiment, the increase of the peak power is beneficial to the blasting ablation of hard thrombus. The average power is within 30 W, which meets the ablation requirement of the tissue and avoids the temperature rise effect caused by high average power, thereby causing additional thermal damage.

[0062] In the embodiment, the repetition frequency of the Q-switched thulium laser is 200 Hz-200 kHz.

[0063] Exemplarily, the repetition frequency of the Q-switched thulium laser is 100 kHz.

[0064] In the embodiment, the repetition frequency is adjustable in a large range, which is beneficial to the ablation of soft thrombus at low repetition frequency and is beneficial to the ablation of hard thrombus at high repetition frequency. Meanwhile, there is a larger pulse width shaping space, which can realize complex time-domain distribution of pulse width, such as pulse train and Moses pulse.

[0065] In the embodiment, the large-range adjustable peak power, pulse width and repetition frequency distribution can be combined to realize complex space-time distribution of pulse width, such as pulse train and Moses pulse. Both are combinations of multiple pulses, and ordinary pulse lasers are one pulse after another, while each pulse of the pulse train and the Moses pulse is composed of multiple small pulses. The peak power of each small pulse does not need to be the same, and the number of small pulses can also be set as required, which has a great editing space. This mode has a wide range of uses and can flexibly distribute energy. For example, when ablation of biological tissue is performed, micro-drilling, cutting and surface treatment and other applications can be performed, and the uniformity and controllability of material removal can be ensured by distributing energy through multiple pulses, which can be used to cope with more complex application scenarios.

[0066] Figure 3 A structure schematic diagram of a thrombus ablation catheter is provided for the embodiment. Referring to FIG. 1, Figure 3The thrombus ablation catheter 21 comprises a first channel 211, a second channel 212 and a third channel 213; the optical fiber 22 and the positioning member 23 are arranged in the first channel 211 and the second channel 212 respectively, and the third channel 213 is used for guiding the ablated thrombus.

[0067] In the embodiment, the first channel 211 is arranged at the center of the thrombus ablation catheter 21, the third channel 213 is arranged at the edge of the thrombus ablation catheter 21, and the third channel 213 surrounds the first channel 211 and the second channel 212.

[0068] In the embodiment, the first to third channels are arranged in the above manner, so that the positioning effect of the positioning member is ensured, and the third channel can better guide the ablated thrombus.

[0069] In the embodiment, the optical fiber 22 is a medical optical fiber with a diameter of 50-600 microns.

[0070] Exemplarily, the diameter of the optical fiber 22 is 100 microns.

[0071] In the embodiment, the diameter of the matched medical optical fiber can reach 50 microns at the minimum, which meets the application scenarios in various small blood vessels. For relatively thick arterial blood vessels, a conventional optical fiber with a diameter of 500 microns can be used to increase the output diameter of the laser spot and improve the ablation efficiency. Overall, it meets various complex application scenarios, and ensures the accuracy and safety while meeting the thrombus ablation.

[0072] In the embodiment, the positioning member 23 comprises a guide wire. By arranging the guide wire, the positioning function can be realized.

[0073] In the embodiment, the thrombus ablation assembly 2 further comprises:

[0074] The thrombus suction unit 24 is in communication with the third channel 213 of the thrombus ablation catheter 21 and is used for sucking the thrombus.

[0075] In the embodiment, the thrombus suction unit 24 is arranged outside the blood vessel.

[0076] In the embodiment, for the thrombus with a larger volume, the thrombus suction unit can better guide it out. When the thrombus is small, it can be carried out by blood flow.

[0077] In the embodiment, the thrombus suction unit 24 comprises a negative pressure suction device. The negative pressure suction device can ensure the suction effect of the thrombus.

[0078] In the embodiment, the thrombus ablation catheter and the medical guide wire, the thrombus suction unit are combined, and the medical optical fiber is fixed on the cross section edge of the thrombus ablation catheter. The design can enter the thrombus lesion through the guide wire in a minimally invasive manner; the medical optical fiber position can make the laser close to the blood vessel edge, and the Q thulium laser can surround the whole blood vessel wall to ablate the thrombus, so that the effect of all-around ring cutting of the thrombus is achieved; the thrombus fragments can be fully circulated through the larger circular cavity, and secondary blockage is not formed.

[0079] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A Q-switched thulium laser therapy system for thrombus ablation, characterized in that, The application relates to a thrombus ablation device. The application relates to a thrombus ablation device. The peak power of the Q-switched thulium laser is 0-20 kW; the average power of the Q-switched thulium laser is 0-30 W; the pulse width of the Q-switched thulium laser is nanosecond level, and the value range is 30-1000 ns; and the repetition frequency of the Q-switched thulium laser is 200 Hz-200 kHz. The diameter of the optical fiber is 50-600 mu m.

2. The Q-switched thulium laser treatment system for thrombus ablation of claim 1, wherein, The thulium laser generating device adopts a master oscillator power amplifier structure and comprises:

3. The Q-switched thulium laser treatment system for thrombus ablation according to claim 1 or 2, characterized in that, a seed light generating assembly and a laser amplification assembly connected in sequence through a thulium-doped optical fiber. The seed light generating assembly is used for generating seed light of a thulium laser and comprises: a first grating and a second grating, an acousto-optic modulation device, a first laser and a first pump light stripping unit arranged in sequence between the first grating and the second grating, and a first laser isolation unit arranged after the second grating, wherein the first laser isolation unit is used for controlling unidirectional transmission of the seed light; and a laser amplification assembly used for amplifying the seed light to form required thulium laser, comprising a plurality of second lasers, a second pump light stripping unit and a second laser isolation unit coupled with the thulium-doped optical fiber, wherein the second laser isolation unit is used for controlling unidirectional transmission of the thulium laser. The thrombus ablation catheter comprises a first channel, a second channel and a third channel; the optical fiber and the positioning member are arranged in the first channel and the second channel respectively, and the third channel is used for passing the ablated thrombus.

4. The Q-switched thulium laser treatment system for thrombus ablation according to claim 1 or 2, characterized in that, The first channel is arranged at the center of the thrombus ablation catheter, the third channel is arranged at the edge of the thrombus ablation catheter, and the third channel surrounds the first channel and the second channel.

5. The Q-switched thulium laser treatment system for thrombus ablation of claim 4, wherein, The thrombus ablation device further comprises:

6. The Q-switched thulium laser treatment system for thrombus ablation of claim 4, wherein, a thrombus suction unit in communication with the third channel of the thrombus ablation catheter and used for sucking the thrombus. The thrombus suction unit comprises a negative pressure suction device.

7. The Q-switched thulium laser treatment system for thrombus ablation of claim 6, wherein, ​

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