Q-switched thulium laser treatment system for thrombus ablation

Abstract

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

Description

Technical Field

[0001] The invention belongs to the field of medical surgical laser equipment, and in particular relates to a Q-switched thulium laser treatment system for thrombus ablation. Background Art

[0002] Thrombosis is the main cause and complication of cardiovascular disease, which can lead to myocardial infarction, acute ischemic stroke or venous thromboembolism. When tissues such as fibrin, red blood cells, platelets and white blood cells are deposited and coagulated in blood vessels, thrombi will form, disrupting blood flow. Thrombi in different parts of the human body, at different formation speeds and in different areas have structural differences, but they all cause damage to the body. At present, the incidence of thrombosis is extremely high. Rapid, effective and safe thrombus ablation technology is a favorable means to maintain human health and reduce social burdens.

[0003] Laser thrombolysis is closely related to laser wavelength, pulse width and power. Pulsed laser has the advantages of high intensity, high precision, low damage to surrounding tissues and few postoperative complications. Therefore, it is widely used in clinical medicine. Different biological tissues have the characteristics of absorbing lasers of different specific wavelengths. The mechanism of action of laser thrombolysis is mainly divided into photochemical effect, photothermal effect and photomechanical effect. The action mechanism of laser thrombolysis is to apply laser of a specific wavelength to thrombus, destroy the molecular bonds of biological tissue or directly ablate tissue through thermal action to achieve the purpose of thrombolysis. Laser that can be effectively absorbed by biological tissue will make it easier to achieve accurate, effective and safe thrombolysis.

[0004] The therapeutic effect of existing thrombus ablation devices is not ideal, and how to provide a treatment system based on laser thrombus ablation has become a top priority. Summary of the invention

[0005] The present invention 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 includes: A thulium laser generating device, used for generating a Q-switched thulium laser; The thrombus ablation component comprises a thrombus ablation catheter and an optical fiber; the optical fiber is arranged in the thrombus ablation catheter and is used to obtain Q-switched thulium laser and emit the Q-switched thulium laser toward the thrombus in the blood vessel.

[0006] Optionally, the pulse width of the Q-switched thulium laser is in the nanosecond range of 30 to 1000 ns.

[0007] 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.

[0008] Optionally, the repetition rate of the Q-switched thulium laser is 200 Hz to 200 kHz.

[0009] Optionally, the diameter of the optical fiber is 50-600 μm.

[0010] Optionally, the thulium laser generating device adopts a master oscillator power amplification structure, comprising: A seed light generating component and a laser amplifying component connected in sequence via thulium-doped optical fibers; The seed light generating component is used to generate the seed light of the thulium laser, and includes: A first grating and a second grating, an acousto-optic modulation device, a first laser and a first pump light stripping unit sequentially arranged between the first grating and the second grating, and a first laser isolation unit arranged behind the second grating, wherein the first laser isolation unit is used to control unidirectional transmission of seed light; The laser amplification component is used to amplify the seed light to form a thulium laser that meets the requirements, including: a plurality of second lasers coupled to the thulium-doped optical fiber, a second pump light stripping unit and a second laser isolation unit, wherein the second laser isolation unit is used to control the unidirectional transmission of the thulium laser.

[0011] Optionally, the thrombus ablation catheter comprises a first channel, a second channel and a third channel; the optical fiber and the positioning member are respectively arranged in the first channel and the second channel, and the third channel is used for the passage of the ablated thrombus.

[0012] Optionally, the first channel is disposed at the center of the thrombus ablation catheter, the third channel is disposed at the edge of the thrombus ablation catheter, and the third channel surrounds the first channel and the second channel.

[0013] Optionally, the thrombus ablation component further includes: The thrombus attracting unit is communicated with the third channel of the thrombus ablation catheter and is used for attracting thrombus.

[0014] Optionally, the thrombus aspiration unit comprises a negative pressure aspirator.

[0015] The beneficial effects brought by the technical solution provided by the present invention are: The present invention provides a Q-switched thulium laser treatment system for thrombus ablation, comprising a thulium laser generating device and a thrombus ablation component, wherein the thrombus ablation component comprises a thrombus ablation catheter and an optical fiber. The thulium laser generating device is used to generate a Q-switched thulium laser, and the thrombus ablation component is used to deliver the Q-switched thulium laser to the thrombus in the patient's blood vessel through an 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 present invention, a nanosecond optical fiber thulium laser (Q-switched thulium laser) with a high peak power is formed and output to the in vivo lumen environment for surgical treatment. The high peak power of the Q-switched thulium laser can better achieve thermal ablation and thermal explosion effects, 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 the extent of damaging normal tissue. By using the Q-switched thulium laser for thrombus ablation, the thrombus ablation effect can be ensured, and the laser can also be prevented from causing damage to the human body. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 A schematic diagram of the structure of a Q-switched thulium laser treatment system for thrombus ablation provided by the present invention; Figure 2 A schematic diagram of the structure of another Q-switched thulium laser treatment system for thrombus ablation provided by the present invention; Figure 3 A schematic diagram of the structure of a thrombus ablation catheter provided in this embodiment.

[0018] The reference numerals are as follows: 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 amplifying assembly; 121: second laser; 122: second beam combiner; 123: second pump light stripping unit; 124: second laser isolation unit; 13: Thulium-doped fiber; 2: thrombus ablation component; 21: thrombus ablation catheter; 211: first channel; 212: second channel; 213: third channel; 22: optical fiber; 23: positioning piece; 24: thrombus attraction unit. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Before formally introducing the technical solution of this application, the main inventive concept of this application is briefly introduced: First, about thulium laser.

[0021] Existing thulium lasers are usually used to crush stones in the medical field, while the present application uses thulium lasers for thrombus ablation. The basic principle is as follows: the wavelength of thulium lasers is at the strong absorption peak of water, and can be completely absorbed by water within a very short distance in water, which can better vaporize and cut tissues and has higher cutting accuracy. When the thulium laser is close to water-rich tissues, precise ablation can be achieved without further transmission and diffusion; when the thulium laser is far away from the target tissue in a liquid environment, liquid media such as water absorb the laser energy to form cavitation, generating strong shock waves and high-speed microjets. This photomechanical effect can also effectively remove plaques such as thrombi, and the effect of clearing plaques is more significant. However, since the thulium laser energy is completely absorbed by water at a very short distance, it is easy to cause excessive local temperature rise, resulting in unnecessary thermal damage.

[0022] Second, perform Q-switching on the thulium laser.

[0023] The extremely high instantaneous power of the Q-switched pulsed thulium laser can produce a micro-explosion effect on biological tissues, combining the advantages of the photothermal effect and the photomechanical effect, concentrating the impact force and the heat-affected zone in the target area, greatly reducing the damage to the surrounding tissues caused by the shock wave and heat diffusion. In addition, the beam quality and collimation characteristics of the Q-switched thulium laser are good, and it has a high energy density and low loss, making it an ideal choice for laser medical treatment. In this application, the ultra-short pulse width and ultra-high peak power output of the thulium laser are achieved through the self-developed Q-switched optical path. During the implementation process, the same output energy can be concentrated in a shorter time, so that the thermal relaxation time per unit time will be more sufficient. Combined with pulse shaping technology, the additional thermal effect of the thulium laser is greatly reduced. (That is, first, ultra-short pulse width and ultra-high peak power output are achieved through Q-switching; second, high peak power and short pulse width are beneficial to reduce long-term heat accumulation, making up for the inherent disadvantages of traditional thulium lasers in thrombus ablation.) Based on the above principle, the present application forms a Q-switched thulium laser treatment system for thrombus ablation, which ensures the ablation effect on thrombus while preventing the thulium laser from causing damage to the human body. For the specific technical solution, please refer to the following embodiment.

[0024] Figure 1 This is a schematic diagram of the structure of a Q-switched thulium laser treatment system for thrombus ablation provided by the present invention. Figure 1 ,include: Thulium laser generating device 1, used for generating Q-switched thulium laser; The thrombus ablation assembly 2 includes a thrombus ablation catheter 21, an optical fiber 22 and a positioning member (in Figure 3 ); The thrombus ablation catheter 21 includes a first channel, a second channel and a third channel; the optical fiber and the positioning member are respectively arranged in the first channel and the second channel, and the third channel is used for the ablated thrombus to pass through.

[0025] The present invention provides a Q-switched thulium laser treatment system for thrombus ablation, comprising a thulium laser generating device and a thrombus ablation component, wherein the thrombus ablation component comprises a thrombus ablation catheter and an optical fiber. The thulium laser generating device is used to generate a Q-switched thulium laser, and the thrombus ablation component is used to deliver the Q-switched thulium laser to the thrombus in the patient's blood vessel through an 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 present invention, a nanosecond optical fiber thulium laser (Q-switched thulium laser) with a high peak power is formed and output to the in vivo lumen environment for surgical treatment. The high peak power of the Q-switched thulium laser can better achieve thermal ablation and thermal explosion effects, 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 the extent of damaging normal tissue. By using the Q-switched thulium laser for thrombus ablation, the thrombus ablation effect can be ensured, and the laser can also be prevented from causing damage to the human body.

[0026] Figure 2 This is a schematic diagram of the structure of another Q-switched thulium laser treatment system for thrombus ablation provided by the present invention. Figure 2 The thulium laser generating device 1 adopts a main oscillator power amplification structure, including: A seed light generating component 11 and a laser amplifying component 12 connected in sequence via a thulium-doped optical fiber 13; The seed light generating component 11 is used to generate the seed light of the thulium laser, and includes: A first grating 111 and a second grating 116, an acousto-optic modulation device 112, a first laser 113 and a first pump light stripping unit 115 arranged in sequence between the first grating 111 and the second grating 116, and a first laser isolation unit 117 arranged behind the second grating, wherein the first laser isolation unit is used to control the unidirectional transmission of the seed light; The laser amplification component 12 is used to amplify the seed light to form a thulium laser that meets the requirements, including: a plurality of second lasers 121 coupled to the thulium-doped optical fiber, a second pump light stripping unit 123 and a second laser isolation unit 124, wherein the second laser isolation unit 123 is used to control the unidirectional 21 transmission of the thulium laser.

[0027] In this embodiment, the first laser 113 is coupled to the thulium-doped optical fiber 13 through the first beam combiner 114 , and the second laser 121 is coupled to the thulium-doped optical fiber 13 through the second beam combiner 122 .

[0028] In this embodiment, the first laser 113 and the second laser 121 are pump sources, including semiconductor lasers.

[0029] In this embodiment, a pulse signal generator may be used to provide an input signal to the acousto-optic modulation device 112 .

[0030] In this embodiment, the thulium-doped optical fiber 13 is a double-clad thulium-doped optical fiber.

[0031] In this embodiment, the first pump light stripping unit 115 and the second pump light stripping unit 123 include cladding light strippers.

[0032] In this embodiment, the first laser isolation unit 117 and the second laser isolation unit 124 are isolators.

[0033] In this embodiment, the seed source of the acousto-optic Q-switching mainly consists of a first grating (i.e., a high-reflection grating), an acousto-optic modulation device, a first laser (i.e., a semiconductor laser), a first beam combiner, a double-clad thulium-doped optical fiber, a cladding light stripper, and a second grating (i.e., a low-reflection grating). An acousto-optic modulator with pigtail output at both ends is inserted into the cavity as an active Q-switching device. A pulse signal generator provides a driving signal for the acousto-optic modulator, which can conveniently adjust the parameters such as the frequency and duty cycle of the laser. The pump source is a 30 W semiconductor laser (103). The pump light is coupled into a double-clad thulium-doped optical 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- and low-reflection gratings with a central wavelength of 1940 nm form a resonant cavity to oscillate and select the laser's emission wavelength. The cladding light stripper is used to strip the remaining pump light. After being emitted from the low-reflection device, the laser passes through the first laser isolation unit (also known as the isolator) to prevent the return light from causing adverse effects on the optical path and ensure the unidirectional propagation of the light beam.

[0034] The amplifier stage (i.e., the laser amplification component) uses two 35 W 793 nm semiconductor lasers, which 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 gain-amplify the seed light. The remaining pump light is then stripped off through the second laser stripping unit (i.e., the cladding light stripper). Finally, the timing-adjustable nanosecond pulse thulium laser is output through the second laser isolation unit (i.e., the isolator). The central wavelength of the output light is 1940 nm.

[0035] In this embodiment, the pulse width of the Q-switched thulium laser is in the nanosecond range of 30 to 1000 ns.

[0036] Exemplarily, the pulse width of the Q-switched thulium laser may be 500ns.

[0037] In this embodiment, a Q-switched thulium laser with a pulse width of nanoseconds is used. The duration of a single laser pulse is one order of magnitude less than the laser-induced bubble annihilation time (the latter is in microseconds), which can ensure that the laser will not penetrate the liquid layer and damage human tissue when operating at a certain distance.

[0038] In this 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.

[0039] 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.

[0040] In this embodiment, the increase in peak power is beneficial to the explosive ablation of hard thrombus. The average power is within 30 watts, which meets the tissue ablation requirements and avoids the temperature rise caused by high average power, which causes additional thermal damage.

[0041] In this embodiment, the repetition rate of the Q-switched thulium laser is 200 Hz to 200 kHz.

[0042] Exemplarily, the repetition rate of the Q-switched thulium laser is 100 kHz.

[0043] In this embodiment, the repetition rate is adjustable over a wide range. A low repetition rate is beneficial to the ablation of soft thrombi, while a high repetition rate is beneficial to the ablation of hard thrombi. At the same time, it has a larger pulse width shaping space and can achieve complex time domain distribution of pulse width, such as pulse trains, Moses pulses, etc.

[0044] In this embodiment, the peak power, pulse width and repetition rate distribution that can be tunable over a wide range are combined to achieve complex spatiotemporal distribution of pulse width, such as pulse trains, Moses pulses, etc. Both are combinations of multiple pulses. Ordinary pulse lasers are one pulse after another, while each pulse of a pulse train and a 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 be set as needed, which has a large editing space. This mode has a wide range of uses and can flexibly allocate energy. For example, when ablating biological tissue, micro-drilling, cutting, and surface treatment can be performed. Distributing energy through multiple pulses can ensure the uniformity and controllability of material removal, and can be used to cope with more complex application scenarios.

[0045] Figure 3 This is a schematic diagram of the structure of a thrombus ablation catheter provided in this embodiment. Figure 3 The thrombus ablation catheter 21 includes a first channel 211, a second channel 212 and a third channel 213; the optical fiber 22 and the positioning member 23 are respectively arranged in the first channel 211 and the second channel 212, and the third channel 213 is used for the passage of the ablated thrombus. The positioning member 23 plays a positioning role when the thrombus ablation catheter moves.

[0046] In this embodiment, the first channel 211 is disposed at the center of the thrombus ablation catheter 21 , the third channel 213 is disposed at the edge of the thrombus ablation catheter 21 , and the third channel 213 surrounds the first channel 211 and the second channel 212 .

[0047] In this embodiment, the first to third channels are arranged in the above manner, which can ensure the positioning effect of the positioning member and can also ensure that the third channel can better lead out the ablated thrombus.

[0048] In this embodiment, the optical fiber 22 is a medical optical fiber with a diameter of 50-600 μm.

[0049] Exemplarily, the diameter of the optical fiber 22 is 100 μm.

[0050] In this embodiment, the smallest diameter of the medical optical fiber that can be matched is 50 microns, which meets the application scenarios in various small blood vessels. For thicker arterial blood vessels, a conventional 500-micron optical fiber diameter 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 overall accuracy and safety while meeting the requirements of thrombus ablation.

[0051] In this embodiment, the positioning member 23 includes a guide wire. By providing the guide wire, the positioning function can be achieved.

[0052] In this embodiment, the thrombus ablation component 2 further includes: The thrombus aspirating unit 24 is connected to the third channel 213 of the thrombus ablation catheter 21 and is used for aspirating thrombus.

[0053] The thrombus aspirating unit 24 is disposed outside the blood vessel.

[0054] In this embodiment, for a larger thrombus, a thrombus suction unit is provided to better draw it out. When the thrombus is smaller, the thrombus can be brought out by blood flow.

[0055] In this embodiment, the thrombus aspirating unit 24 includes a negative pressure aspirator, which can ensure the aspiration effect on the thrombus.

[0056] In this embodiment, the thrombus ablation catheter is combined with a medical guide wire and a thrombus suction unit, and the medical optical fiber is fixed to the cross-sectional edge of the thrombus ablation catheter. This design can enter the thrombus lesion in a minimally invasive manner through the guide wire; the position of the medical optical fiber allows the laser to be close to the edge of the blood vessel, and by rotating the thrombus ablation catheter, the Q-switched thulium laser can surround the entire blood vessel wall to ablate the thrombus, achieving the effect of all-round thrombus cutting; thrombus fragments can be fully circulated through a larger, round-shaped cavity without forming a secondary blockage.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A Q-switched thulium laser treatment system for thrombus ablation, characterized in that: include: A thulium laser generating device, used for generating a Q-switched thulium laser; The thrombus ablation component comprises a thrombus ablation catheter and an optical fiber; the optical fiber is arranged in the thrombus ablation catheter and is used to obtain Q-switched thulium laser and emit the Q-switched thulium laser toward the thrombus in the blood vessel.

2. The Q-switched thulium laser treatment system for thrombus ablation according to claim 1, characterized in that: The pulse width of the Q-switched thulium laser is in the nanosecond range, with a value range of 30-1000ns.

3. The Q-switched thulium laser treatment system for thrombus ablation according to claim 1, characterized in that: 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.

4. The Q-switched thulium laser treatment system for thrombus ablation according to claim 1, characterized in that: The repetition rate of the Q-switched thulium laser is 200 Hz to 200 kHz.

5. The Q-switched thulium laser treatment system for thrombus ablation according to claim 1, characterized in that: The diameter of the optical fiber is 50-600 μm.

6. The Q-switched thulium laser treatment system for thrombus ablation according to any one of claims 1 to 5, characterized in that: The thulium laser generating device adopts a main oscillation power amplification structure, comprising: A seed light generating component and a laser amplifying component connected in sequence via thulium-doped optical fibers; The seed light generating component is used to generate the seed light of the thulium laser, and includes: A first grating and a second grating, an acousto-optic modulation device, a first laser and a first pump light stripping unit sequentially arranged between the first grating and the second grating, and a first laser isolation unit arranged behind the second grating, wherein the first laser isolation unit is used to control unidirectional transmission of seed light; The laser amplification component is used to amplify the seed light to form a thulium laser that meets the requirements, including: a plurality of second lasers coupled to the thulium-doped optical fiber, a second pump light stripping unit and a second laser isolation unit, wherein the second laser isolation unit is used to control the unidirectional transmission of the thulium laser.

7. The Q-switched thulium laser treatment system for thrombus ablation according to any one of claims 1 to 5, characterized in that: The thrombus ablation catheter comprises a first channel, a second channel and a third channel; the optical fiber and the positioning member are respectively arranged in the first channel and the second channel, and the third channel is used for the passage of the ablated thrombus.

8. The Q-switched thulium laser treatment system for thrombus ablation according to claim 7, 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.

9. The Q-switched thulium laser treatment system for thrombus ablation according to claim 7 or 8, characterized in that: The thrombus ablation assembly further comprises: The thrombus attracting unit is communicated with the third channel of the thrombus ablation catheter and is used for attracting thrombus.

10. The Q-switched thulium laser treatment system for thrombus ablation according to claim 9, characterized in that: The thrombus aspiration unit includes a negative pressure aspirator.

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