Laser scanning method, laser irradiation device, and laser treatment system

Abstract

The laser scanning method is a method of causing a laser beam (L) emitted from a front end (11b) of an optical fiber (11) in a medium (M) of a liquid to scan. The laser scanning method includes a process of emitting a pulsed laser beam (L) from the front end (11b) in the medium (M), the process of emitting the pulsed laser beam (L) including processes of generating a bubble (B) in contact with the front end (11b) and an acting member (13) by the laser beam (L) emitted from the front end (11b), the acting member (13) being disposed only on one side (t0, t1, t5) of the front end (11b) in a radial direction of the optical fiber (11); and shrinking the bubble (B) (t2, t3) by stopping the emission of the laser beam (L) from the front end (11b).

Description

Technical Field

[0001] This invention relates to a laser scanning method, a laser irradiation device, and a laser therapy system. Background Technology

[0002] Previously, a medical device for scanning a laser beam used for treatment or imaging was known (see, for example, Non-Patent Documents 1 and 2). In Non-Patent Documents 1 and 2, an optical fiber was vibrated by an actuator, thereby causing the laser beam emitted from the tip of the optical fiber to scan. Specifically, in Non-Patent Document 1, an electromagnetic actuator was used, having a magnetic bead fixed to the optical fiber and a solenoid disposed around the magnetic bead. In Non-Patent Document 2, a piezoelectric actuator was used, having a piezoelectric element fixed to the optical fiber.

[0003] Existing technical documents

[0004] Non-patent literature

[0005] Non-patent literature 1: Layton A. Hall, 2 others, “Thulium fiber laser stone dusting using an automated, vibrating optical fiber.”, Proceedings, Volume 10852, Therapeutics and Diagnostics in Urology 2019, 108520C, February 26, 2019

[0006] Non-patent literature 2: Lee, CM, and 4 others, “Scanning fiber endoscopy with highly flexible, 1mm catheter scopes for wide-field, full-color imaging.” Journal of Biophotonics, June 3, 2010, Volume 3, pp. 385-407. Summary of the Invention

[0007] The problem the invention aims to solve

[0008] In Non-Patent Documents 1 and 2, actuators are arranged around the optical fiber, thus increasing the diameter of the device. Furthermore, current needs to be supplied to the actuators, increasing power consumption. Additionally, the resonant frequency of the optical fiber differs in air and water, making it difficult to use the actuators described in Non-Patent Documents 1 and 2 to create a resonant state in the optical fiber in water, and thus difficult to achieve the vibration amplitude of the optical fiber required for laser beam scanning.

[0009] The present invention was made in view of the above circumstances, and its object is to provide a laser scanning method, a laser irradiation device, and a laser therapy system that enables a laser beam to scan in a liquid medium without requiring the addition of an actuator to drive the optical fiber and without increasing power consumption.

[0010] Solution for solving the problem

[0011] To achieve the above objectives, the present invention provides the following solution.

[0012] A first aspect of the present invention is a laser scanning method for scanning a laser beam emitted from the tip of an optical fiber in a liquid medium. The laser scanning method includes a step of emitting a pulsed laser beam from the tip of the optical fiber in the liquid medium. This step of emitting the pulsed laser beam includes the following steps: generating a bubble that contacts the tip of the optical fiber and an actuating member by means of the laser beam emitted from the tip of the optical fiber, the actuating member being radially disposed on one side of the tip of the optical fiber; and causing the bubble to contract by stopping the emission of the laser beam from the tip of the optical fiber.

[0013] A second aspect of the present invention is a laser irradiation device comprising: an optical fiber; a support member that cantilever beams the vibration region of the optical fiber, including the front end of the optical fiber; and an action member disposed radially on only one side of the front end of the optical fiber.

[0014] A third aspect of the present invention is a laser therapy system comprising: the laser irradiation device described above; and a laser oscillator that generates a therapeutic laser beam and supplies the therapeutic laser beam to the optical fiber of the laser irradiation device, wherein the laser oscillator generates a pulsed laser beam that generates bubbles in a liquid medium as the therapeutic laser beam.

[0015] The effects of the invention

[0016] According to the present invention, the following effects can be achieved: no additional actuator for driving the optical fiber is required and the power consumption is not increased, enabling the laser beam to scan in a liquid medium. Attached Figure Description

[0017] Figure 1 This is an overall structural diagram of a laser therapy system according to one embodiment of the present invention.

[0018] Figure 2 This is a structural diagram of a laser irradiation device according to one embodiment of the present invention.

[0019] Figure 3A It is a diagram illustrating the isotropic contraction of a bubble when no active component is present.

[0020] Figure 3B It is a diagram illustrating the anisotropic contraction of the bubble and the effect of the action component when an action component is present.

[0021] Figure 4 This is an explanation Figure 2 The diagram illustrates the process by which the optical fiber of a laser irradiation device vibrates due to the emission of a pulsed laser beam.

[0022] Figure 5A This is a diagram showing the preferred positional relationship between the front end of the optical fiber and the functional component.

[0023] Figure 5B This is a diagram showing the non-preferred positional relationship between the front end of the optical fiber and the functional component.

[0024] Figure 6A This is a diagram showing the preferred positional relationship between the front end of the optical fiber and the functional component.

[0025] Figure 6B This is a diagram showing the non-preferred positional relationship between the front end of the optical fiber and the functional component.

[0026] Figure 7 This is a flowchart of a laser treatment method according to one embodiment of the present invention.

[0027] Figure 8A This is a diagram illustrating the experimental conditions of an embodiment of the present invention.

[0028] Figure 8B The experimental results of an embodiment of the present invention are a graph showing the relationship between pulse frequency and vibration amplitude at the front end of the optical fiber.

[0029] Figure 9A This is a partial structural diagram of a laser irradiation device according to another embodiment of the present invention.

[0030] Figure 9B This is a partial structural diagram of a laser irradiation device according to another embodiment of the present invention.

[0031] Figure 10A This is an overall structural diagram of a laser therapy system according to another embodiment of the present invention.

[0032] Figure 10B This is an overall structural diagram of a laser therapy system according to another embodiment of the present invention.

[0033] Figure 11 This is a structural diagram of a laser irradiation device according to another embodiment of the present invention.

[0034] Figure 12AThis diagram illustrates the anisotropic contraction of bubbles and the function of the working components.

[0035] Figure 12B It is a diagram illustrating the function of the components.

[0036] Figure 13 This is an explanation Figure 11 The diagram illustrates the process by which the optical fiber of a laser irradiation device vibrates due to the emission of a pulsed laser beam.

[0037] Figure 14A This is a partial longitudinal cross-sectional view showing the structure of a laser irradiation device according to another embodiment of the present invention.

[0038] Figure 14B yes Figure 14A A top view of the laser irradiation device.

[0039] Figure 14C yes Figure 14A Front view of the laser irradiation device.

[0040] Figure 15A This is a top view showing the structure of a laser irradiation apparatus according to another embodiment of the present invention.

[0041] Figure 15B yes Figure 15A Front view of the laser irradiation device. Detailed Implementation

[0042] Hereinafter, a laser scanning method, a laser irradiation device, and a laser treatment system according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0043] like Figure 1 As shown, the laser therapy system 100 according to this embodiment is a system that uses a laser beam L to treat a treatment subject A. The laser therapy system 100 includes a laser irradiation device 1, an endoscope 2, a laser oscillator 3, a frequency control unit 4, a dynamic detection unit 5, a resonance determination unit 6, and a display unit 7.

[0044] Endoscope 2 is, for example, a rigid or flexible ureteroscope. Endoscope 2 has a treatment instrument channel 2a extending through the endoscope 2 along its long side.

[0045] like Figure 2 As shown, the laser irradiation device 1 includes an optical fiber 11, a tubular outer sheath (support member) 12 supporting the optical fiber 11, and an action member 13. Figure 2 It is a longitudinal section view obtained by cutting along the long axis of the optical fiber 11 and the outer sheath 12.

[0046] Optical fiber 11 is, for example, a single-mode optical fiber with a cladding diameter of 125 μm. Optical fiber 11 can also be a multimode optical fiber or a double-clad optical fiber.

[0047] The outer sheath 12 can be inserted into the treatment device channel 2a. The optical fiber 11 extends through the outer sheath 12 along the long side, and the front end portion of the optical fiber 11 protrudes from the front end of the outer sheath 12.

[0048] The front end 12a of the outer sheath 12 is a support portion that supports the optical fiber 11 at a distance spaced from the front end 11b of the optical fiber 11 toward the base end. The inner diameter of the support portion 12a is smaller than the inner diameter of the other parts of the outer sheath 12, and the inner diameter of the support portion 12a is equal to or slightly larger than the outer diameter of the optical fiber 11. Therefore, the position of the optical fiber 11 is fixed radially within the support portion 12a. As a result, the vibration region 11a of the optical fiber 11, which is located on the front end side of the support portion 12a and includes the front end 11b, is supported by the outer sheath 12 in a cantilever beam shape, and the vibration region 11a can vibrate radially with the portion at the support portion 12a of the optical fiber 11 as a fulcrum.

[0049] The actuating member 13 is a plate-shaped component arranged parallel to the vibration region 11a and fixed to the outer sheath 12. The actuating member 13 is disposed only on one side of the optical fiber 11 in the radial direction, and is separated from the front end of the optical fiber 11 by a distance d in the radial direction of the optical fiber 11. The surface of the actuating member 13 on the optical fiber 11 side can be either a flat surface or a curved surface protruding towards the optical fiber 11 side.

[0050] The vibrating region 11a and the actuating member 13, disposed on the outside of the outer sheath 12, are exposed to the outside of the laser irradiation device 1. Therefore, when the laser irradiation device 1 is used in the medium M, the vibrating region 11a and the actuating member 13 are covered by the medium M. The resonant frequency of the vibrating region 11a varies depending on the diameter and length of the vibrating region 11a, and the medium M surrounding the vibrating region 11a. For example, in the case of a vibrating region 11a with a core diameter of 272 μm, a cladding diameter of 322 μm, and a length of 45 mm, the resonant frequency is 126 Hz in air and 70 Hz to 80 Hz in water.

[0051] The base end of optical fiber 11 is connected to laser oscillator 3 via a connector or other connecting component (not shown). A pulsed infrared laser beam L is supplied from laser oscillator 3 to optical fiber 11, and the laser beam L exits from the front end 11b of optical fiber 11. In the liquid medium M, the laser beam L is absorbed by the medium M, causing the temperature of the medium M to rise, thereby generating a bubble B at the front end 11b (see reference). Figures 3A to 4The medium M is a bodily fluid such as water, saline, perfusion fluid, non-electrolyte solution, or urine. The formation and collapse of bubble B are repeated synchronously with the pulse frequency of the laser beam L. Specifically, during the emission of the laser beam L, bubble B is formed and grows, and by stopping the emission of the laser beam L, bubble B rapidly contracts and collapses.

[0052] The action component 13 is positioned at the point where bubble B will come into contact, so that the contraction force generated when bubble B contracts acts on the vibration region 11a of optical fiber 11.

[0053] like Figure 3A As shown, when there are no objects around bubble B, water pressure P acts equally on bubble B from all directions, causing bubble B to contract isotropically. On the other hand, as... Figure 3B As shown, when the actuating member 13 is present only on one side of bubble B and bubble B is in contact with the actuating member 13, the water pressure P acts unevenly on bubble B, causing bubble B to contract in the direction toward the actuating member 13. Therefore, by virtue of the presence of the actuating member 13, the contraction force of bubble B in the radial direction of the vibration region 11a can be applied to the front end 11b, causing the front end 11b to vibrate radially.

[0054] The material of the actuating member 13 is not particularly limited. When the surface of the actuating member 13 is hydrophobic, the contraction force of bubble B becomes greater compared to when the surface is hydrophilic. Therefore, it is preferable that the surface of the actuating member 13 on the fiber 11 side is hydrophobic.

[0055] Figure 4 This explains the process by which bubble B is generated, contracts, and collapses along with the emission of a pulsed laser beam L, thereby causing the optical fiber 11 to vibrate.

[0056] First, a bubble B (t = t0) is generated in contact with the action member 13 by starting to emit a laser beam L from the front end 11b of the optical fiber 11. During the emission of the laser beam L, the bubble B grows to a specified size (t = t1).

[0057] Next, the laser beam L is stopped, causing bubble B to contract. The radial contraction force F of the optical fiber 11 towards the action member 13 acts on the front end 11b (t = t2). During the contraction of bubble B, the front end 11b moves radially towards the action member 13 along the contraction force F (t = t3).

[0058] Then, when bubble B bursts and the contraction force F disappears, the front end 11b moves radially in the optical fiber 11 toward the side opposite to the action member 13 due to the elastic restoring force of the vibration region 11a (t = t4).

[0059] Next, by emitting a laser beam L from the front end 11b of the optical fiber 11, a bubble B (t = t5) is generated again to contact the action member 13. The timing of starting to emit the laser beam L is controlled in such a way that the bubble B grows to a specified size when the front end 11b returns to the position at t = t0 and t1, i.e., the initial position.

[0060] Subsequently, by repeating t2 to t5, the front end 11b vibrates radially, causing the laser beam L emitted from the front end 11b to scan in one dimension.

[0061] Figure 5A and Figure 5B This describes the radial positional relationship between the front end 11b of optical fiber 11 and the functional member 13. For example... Figure 5A As shown, to ensure reliable contact between bubble B and the actuating member 13, the distance d between the front end 11b and the actuating member 13 is less than or equal to the radius r of bubble B, which is a predetermined upper limit. The radius r is the radius of bubble B generated by the laser beam L when there are no objects around the front end 11b. Figure 5B As shown, when the interval d is larger than the radius r, the bubble B contracts isotropically, thus preventing the radial contraction force of the optical fiber 11 from acting on the front end 11b.

[0062] Furthermore, the contraction force varies depending on the spacing d, the diameter of the fiber 11, and the irradiation conditions of the laser beam L. When the spacing d is too small, the contraction force weakens. The optimal spacing d that yields sufficient contraction force is uniquely determined based on the diameter of the fiber 11 and the irradiation conditions of the laser beam L.

[0063] Figure 6A and Figure 6B This describes the positional relationship between the front end 11b of optical fiber 11 and the functional member 13, along the long side of optical fiber 11. For example... Figure 6A As shown, in order to ensure reliable contact between bubble B and the actuating member 13, the front end 13a of the actuating member 13 is positioned at the same location as or protruding beyond the front end 11b. Figure 6B As shown, when the front end 13a retracts to a position closer to the base end than the front end 11b, there is a possibility that bubble B may not contact the actuating member 13. To allow a greater contraction force to act on the front end 11b, it is preferable that the contact area between bubble B and the actuating member 13 is large. Therefore, it is preferable that... Figure 5A As shown, the front end of the functional member 13 protrudes beyond the front end 11b.

[0064] Laser oscillator 3 generates and outputs a pulsed laser beam L for treating the subject A. For example, the laser beam L is infrared light with a pulse frequency from a few Hz to 1000 Hz. Laser oscillator 3 is, for example, a thulium fiber laser, a holmium YAG laser, a thulium YAG laser, an erbium YAG laser, a pulsed dye laser, or a Q-switched Nd:YAG laser. Laser oscillator 3 is connected to a foot switch 8; when foot switch 8 is pressed, laser oscillator 3 generates and outputs the laser beam L.

[0065] The frequency control unit 4 controls the pulse frequency of the laser beam L generated by the laser oscillator 3. Additionally, during calibration operations to measure the resonant frequency of the vibration region 11a, the frequency control unit 4 changes the pulse frequency generated by the laser oscillator 3. For example, the calibration operation can be performed by the operator inputting an instruction for the calibration operation using an input device (not shown) and pressing the foot switch 8.

[0066] The dynamic detection unit 5 detects the dynamics of the vibrating optical fiber 11. The dynamics include at least the vibration amplitude of the front end 11b of the optical fiber 11, and may also include the vibration frequency. Specifically, the dynamic detection unit 5 has a vibration detection element 5a fixed to the outer sheath 12. The vibration detection element 5a is, for example, a vibration sensor, a pressure sensor, or a strain gauge. The vibration of the vibration region 11a is transmitted to the vibration detection element 5a via the support portion 12a and detected by the vibration detection element 5a. The detection signal output by the vibration detection element 5a varies at the same frequency as the vibration frequency of the vibration region 11a; the larger the vibration amplitude of the front end 11b, the larger the amplitude of the detection signal. The dynamic detection unit 5 detects the vibration frequency and vibration amplitude of the optical fiber 11 based on the vibration frequency and vibration amplitude of the detection signal.

[0067] During the calibration process, the resonance determination unit 6 determines whether the vibration of the optical fiber 11 resonates with the frequency of the laser beam L based on the dynamics detected by the dynamic detection unit 5. Specifically, the resonance determination unit 6 determines the vibration frequency at which the vibration amplitude reaches its maximum as the resonant frequency of the vibration region 11a.

[0068] After the resonance determination unit 6 determines the resonance frequency, the frequency control unit 4 sets the pulse frequency of the laser beam L generated by the laser oscillator 3 to a frequency equal to the resonance frequency.

[0069] Display unit 7 can be any type of display device such as a liquid crystal display. Display unit 7 displays an endoscopic image of the endoscope 2, including the tip 11b of the optical fiber 11 and the patient A. Additionally, display unit 7 displays the dynamics of the optical fiber 11 detected by the dynamic detection unit 5. For example, display unit 7 displays a graph obtained during calibration that shows the relationship between pulse frequency and vibration amplitude. Display unit 7 may also display the resonant frequency determined by the resonance determination unit 6.

[0070] Next, the laser treatment method using the laser irradiation device 1 and the laser treatment system 100 will be described.

[0071] like Figure 7 As shown, the laser treatment method includes: step S1, configuring a laser irradiation device 1 inside the body; steps S2 to S6, calibrating the resonant frequency of the vibration region 11a of the optical fiber 11; and step S7, irradiating the treatment object A with a laser beam L from the laser irradiation device 1 to scan the laser beam L. Steps S2 to S7 are a laser scanning method according to one embodiment of the present invention.

[0072] In step S1, the operator inserts endoscope 2 into the patient C's body, for example, into the ureter, inserts laser irradiation device 1 into the body through the treatment instrument channel 2a, and positions the vibration region 11a of the optical fiber 11 on the outside of the endoscope 2. The endoscope 2 and the vibrating region 11a are surrounded by a liquid medium M.

[0073] Next, in steps S2 to S6, the practitioner causes the laser therapy system 100 to perform a calibration operation to measure the resonant frequency of the vibration region 11a. During the calibration operation, the frequency control unit 4 causes the laser oscillator 3 to generate a pulsed laser beam L, thereby repeatedly emitting the pulsed laser beam L from the tip 11b of the optical fiber 11 (step S2). In addition, the pulse frequency of the laser beam L is continuously or gradually changed by the frequency control unit 4 (step S3).

[0074] In step S2, the following steps are repeated alternately: a bubble B is generated using a laser beam L emitted from the front end 11b, which contacts the front end 11b and the actuating member 13, and the bubble B grows ( Figure 4 (t = t0, t1, t5); and by stopping the laser beam L emitted from the front end 11b, the bubble B contracts ( Figure 4 (t = t2, t3). When bubble B contracts, a radial force F acts on the front end 11b, causing the front end 11b to vibrate radially.

[0075] The front end 11b vibrates synchronously with the pulse frequency of the laser beam L. The vibration amplitude of the front end 11b reaches its maximum when the pulse frequency matches the resonant frequency of the vibration region 11a. The dynamic detection unit 5 detects the dynamics including the vibration amplitude of the front end 11b (step S4), and the resonance determination unit 6 determines that the pulse frequency at which the vibration amplitude is maximum is the resonant frequency of the vibration region 11a (step S5). The frequency control unit 4 sets the pulse frequency of the therapeutic laser beam L to the resonant frequency determined by the resonance determination unit 6 (step S6). In one example, the pulse frequency is 50Hz to 100Hz, preferably 70Hz to 80Hz.

[0076] Next, in step S7, the practitioner uses a foot switch 8 to irradiate a pulsed laser beam L from the tip 11b of the optical fiber 11 onto the treatment subject A, thereby treating the treatment subject A. Similar to step S2, in step S7, the following steps are alternately repeated: a bubble B is generated using the laser beam L emitted from the tip 11b, which contacts the tip 11b and the action member 13, and the bubble B grows; and the bubble B contracts by stopping the emission of the laser beam L from the tip 11b. During the contraction of the bubble B, a radial force F acts on the tip 11b, causing the tip 11b to vibrate radially.

[0077] In step S7, the pulse frequency of the laser beam L is equal to its resonant frequency. Therefore, during the irradiation of the laser beam L, the vibration region 11a vibrates with sufficient amplitude, and the laser beam L scans the treatment object A. Consequently, compared to the case where the tip 11b is stationary, the laser beam L can be irradiated over a wider area, thus treating a larger area of ​​the treatment object A. For example, if the treatment object A is a stone, the tip of the endoscope 2 can be kept in the same position to pulverize a large area of ​​the stone A.

[0078] In this way, the laser irradiation device 1 of this embodiment uses the contraction force of the bubble B generated at the tip 11b of the optical fiber 11 as the driving force to vibrate the tip 11b. The bubble B is generated using a therapeutic laser beam L emitted from the tip 11b. That is, it is not necessary to add an actuator to the optical fiber 11 to drive the optical fiber 11. Therefore, a narrow-diameter laser irradiation device 1 can be easily realized. In addition, the function of scanning the laser beam L can be added to the laser treatment system 100 without increasing the power consumption of the laser treatment system 100.

[0079] Furthermore, if an electromagnetic actuator or piezoelectric actuator is used in the vibration of the optical fiber 11, the electromagnetic field generated by the actuator may affect the endoscopic image. According to this embodiment, the laser beam L used for treatment is infrared light, thus preventing any interference with the endoscopic image.

[0080] Furthermore, the resonant frequency of the vibration region 11a differs between air and the liquid medium M, making it difficult to accurately predict the resonant frequency of the vibration region 11a in the operating environment. Moreover, to obtain the vibration amplitude of the front end 11b required for scanning the laser beam L in the liquid medium M, it is crucial to match the pulse frequency with the resonant frequency of the vibration region 11a to achieve resonance. When the pulse frequency and resonant frequency differ, sufficient vibration amplitude of the vibration region 11a is difficult to obtain due to the viscous resistance of the medium M. According to this embodiment, the resonant frequency can be calibrated by positioning the vibration region 11a in the treatment environment, allowing for accurate measurement of the resonant frequency of the vibration region 11a in the treatment environment. Therefore, during treatment, the vibration region 11a can vibrate with maximum amplitude to obtain the maximum scanning range of the laser beam L.

[0081] Figure 8A and Figure 8B An example of calibrating the resonant frequency of optical fiber 11 is shown.

[0082] like Figure 8A As shown, the vibration region 11a of the optical fiber 11 and the action member 13 are placed in water as a medium M. A pulsed laser beam L is supplied from the laser oscillator 3 to the optical fiber 11, and the vibration amplitude of the front end 11b of the optical fiber 11 is measured while changing the pulse frequency of the laser beam L.

[0083] The length of the vibration region 11a is 45 mm, and the distance d between the front end 11b and the active component 13 is 453 μm. The optical fiber 11 is a MedTech HLFDBX0270C Dornier (core diameter 270 μm, manufactured by Olympus). The active component 13 is a tube. A thulium fiber laser (TLR-50 / 500-QCW AC, manufactured by IPG Photonics) is used as the laser oscillator 3. The laser beam L is irradiated under the following conditions: 500 W, 0.4 ms, 0.2 J, 5 Hz to 200 Hz. Motion images of the vibrating optical fiber 11 are captured at 250 fps using a high-speed camera (FASTCAM-1024PCI, manufactured by Photron).

[0084] The experimental procedure is as follows.

[0085] (1) The pulse frequency is changed from 5Hz to 35Hz in 5Hz intervals, and the laser beam L is irradiated every 0.5 seconds.

[0086] (2) The pulse frequency is changed from 40Hz to 200Hz in 10Hz increments, and the laser beam L is irradiated every 0.5 seconds.

[0087] (3) Measure the maximum amplitude of the front end 11b of the active component 13 at each pulse frequency based on the motion image.

[0088] Figure 8B The results of the above experiment are shown, with the horizontal axis representing the pulse frequency and the vertical axis representing the vibration amplitude of the front end 11b. For example... Figure 8B As shown, it has been confirmed that the vibration amplitude is largest at 70Hz and 80Hz, and the resonant frequency of vibration region 11a is 70Hz to 80Hz. In addition, according to the motion image, it has been confirmed that vibration region 11a begins to vibrate when bubble B contracts, as it is attracted to the action member 13.

[0089] In the above embodiment, the laser irradiation device 1 is provided with an outer sheath 12 for housing the optical fiber 11 as a support member, and the outer sheath 12 and the optical fiber 11 are inserted into the treatment device channel 2a together. However, the structure of the support member is not limited to this. As long as the optical fiber 11 can be supported in a cantilever beam shape at the fulcrum, it can be changed to any other way. Figure 9A and Figure 9B Other examples of support members are shown.

[0090] Figure 9A The support member 121 is an external type that is mounted on the outer surface of the front end of the endoscope 2. The support member 121 is a long strip extending along the long side of the endoscope 2, having a mounting portion 121a mounted on the side of the front end of the endoscope 2 and a support portion 121b for supporting the optical fiber 11. An actuating member 13 is fixed to the front end of the support member 121. The support portion 121b is a plate-shaped member disposed in front of the front end face of the endoscope 2, having a hole through which the optical fiber 11 passes. The portion of the optical fiber 11 at the support portion 121b serves as a fulcrum. To ensure that the distance between the front end 11b of the optical fiber 11 and the actuating member 13 is appropriate, the actuating member 13 protrudes from the support member 121 toward the optical fiber 11 side.

[0091] Figure 9B The support member 122 is a ring-shaped or cylindrical component fixed to the outer surface of the optical fiber 11. The optical fiber 11 passes through the support member 122, and the portion of the optical fiber 11 at the support member 121 becomes a fulcrum.

[0092] In the above embodiment, the dynamic detection unit 5 is configured to use the vibration detection element 5a to detect the dynamics of the vibration region 11a. However, the specific structure of the dynamic detection unit 5 is not limited to this, and other means can also be used to detect the dynamics.

[0093] Figure 10A and Figure 10B Other examples of the dynamic detection unit 5 are shown.

[0094] Figure 10AThe dynamic detection unit 51 of the laser treatment system 100 detects dynamics based on the endoscopic image including the front end 11b acquired by the endoscope 2 during calibration. The dynamic detection unit 51 includes an image information extraction unit 51a and a dynamic recognition unit 51b.

[0095] The image information extraction unit 51a extracts image information related to the vibration of the tip 11b from the endoscopic image. For example, the image information is the tip 11b of the optical fiber 11, the bubble B, or the reflected light of the guide light. The guide light shines from the tip 11b onto an object such as the treatment subject A and is reflected by the object.

[0096] The dynamic recognition unit 51b identifies the dynamic vibration amplitude and vibration frequency of the front end 11b based on changes in image information (e.g., changes in position).

[0097] Figure 10B The dynamic detection unit 52 of the laser therapy system 100 detects dynamics based on the measurement light L' returned from the treatment object A or the like via the optical fiber 11. The dynamic detection unit 52 includes a light source 52a, a photodetector 52b, and a light intensity recognition unit 52c.

[0098] The laser beam output by the light source 52a is used as the measurement light L'. The measurement light L' is combined with the laser beam L through mirrors 52d and 52e and then incident on the base end of the optical fiber 11. It then passes through the front end 11b of the optical fiber 11, the treatment object A, the front end 11b, the base end 11c, mirror 52e, and mirror 52d before being incident on the photodetector 52b.

[0099] When the front end 11b is stationary, the intensity of the measuring light L' incident on the photodetector 52b is constant. When the front end 11b vibrates, the intensity of the measuring light L' incident on the photodetector 52b varies depending on the vibration amplitude and frequency of the front end 11b.

[0100] The light intensity recognition unit 52c identifies the dynamic vibration amplitude and vibration frequency of the vibration region 11a based on the intensity of the measurement light L' detected by the photodetector 52b.

[0101] In the above embodiments, such as Figure 10A and Figure 10B As shown, the laser therapy system 100 may also include a setting unit 9 for the operator to manually set the pulse frequency of the laser beam L. The operator can observe the endoscopic image displayed on the display unit 7 during calibration, determine the pulse frequency at which the vibration amplitude of the front end 11b is at its maximum, and use the setting unit 9 to set the determined pulse frequency to the frequency control unit 4.

[0102] In the above embodiment, the actuating member 13 is positioned radially at a distance d from the front end 11b of the optical fiber 11. However, alternatively, it can be positioned as follows: Figure 11As shown, the actuating member 13 contacts and is fixed to the front end 11b of the optical fiber 11. That is, the interval d can also be zero. In this case, the actuating member 13 is not fixed relative to the supporting member 12 and vibrates integrally with the front end 11b.

[0103] Figure 11 The laser irradiation device 1's working component 13 causes the jet of water generated when bubble B contracts to act on the vibration region 11a of optical fiber 11.

[0104] like Figure 12A As shown, when the actuating member 13 exists only on one side of bubble B and bubble B is in contact with the actuating member 13, the water pressure acts unevenly on bubble B, causing bubble B to contract towards the actuating member 13. During bubble B's contraction, a radial jet of water (refer to) is generated towards the vibration zone 11a of the actuating member 13. Figure 12A (The arrow.) The actuating member 13 bears the jet of water. Therefore, through the presence of the actuating member 13, it is possible to... Figure 12B As shown, the vibration region 11a vibrates radially.

[0105] To generate a stronger jet of water when bubble B contracts, it is preferable that... Figures 11 to 12B The surface of the optical fiber 11 side of the functional component 13 is also hydrophobic.

[0106] Figure 13 This explains the process by which bubble B is generated, contracts, and collapses along with the emission of a pulsed laser beam L, thereby causing the optical fiber 11 to vibrate.

[0107] First, a bubble B (t = t0) is generated in contact with the action member 13 by starting to emit a laser beam L from the front end 11b of the optical fiber 11. During the emission of the laser beam L, the bubble B grows to a specified size (t = t1).

[0108] Next, the laser beam L is stopped, causing bubble B to contract and generate a radial jet of water towards the optical fiber 11 of the action member 13 (refer to the arrow) (t = t2). During the contraction of bubble B, the action member 13 and the front end 11b move radially together along the jet of water (t = t3).

[0109] Then, when the jet of water disappears, the front end 11b and the action member 13 move radially to opposite sides due to the elastic restoring force of the vibration region 11a (t = t4).

[0110] Next, by emitting a laser beam L from the front end 11b of the optical fiber 11, a bubble B (t = t5) is generated again to contact the action member 13. The timing of starting to emit the laser beam L is controlled in such a way that the bubble B grows to a specified size when the front end 11b returns to the position at t = t0 and t1, i.e., the initial position.

[0111] Subsequently, by repeating t2 to t5, the front end 11b vibrates radially, causing the laser beam L emitted from the front end 11b to scan in one dimension.

[0112] In the above embodiment, the laser beam L is scanned in one dimension by the one-dimensional vibration of the front end 11b of the optical fiber 11. However, alternatively, the laser beam L can also be scanned in two dimensions by the two-dimensional vibration of the front end 11b of the optical fiber 11.

[0113] Figures 14A to 14C An example of the structure of a laser irradiation device 1 that causes the front end 11b of the optical fiber 11 to vibrate in two dimensions is shown. Figure 14A This is a longitudinal cross-sectional view obtained by cutting along the long axis of the optical fiber 11 and the outer sheath 12. Figure 14B Viewed from above Figure 14A A top view obtained from a laser irradiation device. Figure 14C Viewed from the front side along the long axis Figure 14A The front view is obtained by using a laser irradiation device.

[0114] A displacement member 14 is fixed on the surface of the action member 13 on the fiber 11 side. The displacement member 14 protrudes from the action member 13 toward the fiber 11 side and is used to displace the vibration region 11a in a direction that intersects the movement direction of the front end 11b based on the contraction force of the bubble B. Figure 14C The displacement member 14 shown has a generally elliptical cross-sectional shape, but the shape of the displacement member 14 is not limited to this and can be appropriately modified. For example, the displacement member 14 may also have a triangular cross-sectional shape.

[0115] exist Figure 14C In the process, bubble B is generated when the front end 11b is positioned to the left of the displacement member 14. As the front end 11b moves to the right due to the contraction force of bubble B, it also moves vertically by crossing the displacement member 14. Thus, the laser beam L scans two-dimensionally along an arc-shaped trajectory.

[0116] Next, bubble B is generated when the front end 11b reaches the right side of the displacement member 14. As the front end 11b moves to the left using the contraction force of bubble B, it also moves vertically by crossing the displacement member 14. Thus, the laser beam L scans two-dimensionally along an arc-shaped trajectory.

[0117] Figure 15A and Figure 15B Other structural examples of the laser irradiation device 1 that causes the front end 11b of the optical fiber 11 to vibrate in two dimensions are shown. Figure 15A This is a top view of the laser irradiation device taken from above. Figure 15B Viewed from the front side along the long axis Figure 15A The front view is obtained by using a laser irradiation device.

[0118] Fins 15 are fixed to the side of the vibration region 11a. Figure 15B In the vibration region 11a, when it vibrates in the left-right direction due to the contraction force of bubble B or the jet of water, the fin 15 is subjected to the resistance of the medium M, thereby causing the front end 11b to move in the up-down direction. Therefore, the front end 11b can be moved in two dimensions as shown by the arrow, thereby enabling the laser beam L to scan in two dimensions.

[0119] Furthermore, the laser therapy system 100 includes at least one processor, such as a central processing unit, and memories such as RAM (random access memory) and ROM (read-only memory). At least a portion of the functions described above in the frequency control unit 4, dynamic detection units 5, 51, 52, and resonance determination unit 6 are implemented by the processor executing programs stored in the memory. Some functions of the frequency control unit 4, dynamic detection units 5, 51, 52, and resonance determination unit 6 can also be implemented using dedicated logic circuits, etc.

[0120] Explanation of reference numerals in the attached figures

[0121] 1: Laser irradiation device; 2: Endoscope (image acquisition unit); 3: Laser oscillator; 4: Frequency control unit; 5, 51, 52: Dynamic detection unit; 6: Resonance determination unit; 7: Display unit; 11: Optical fiber; 11a: Vibration area; 11b: Front end; 12, 121, 122: Supporting components; 13: Acting component; 100: Laser treatment system; A: Treatment object; B: Bubble; L: Laser beam; M: Medium.

Claims

1. A laser irradiation device, comprising: A laser oscillator that supplies a pulsed laser beam, emitted from the tip of an optical fiber in a liquid medium, to an optical fiber; and The control unit controls the emission of the pulsed laser beam generated by the laser oscillator. in, The control unit repeatedly controls the supply of the laser beam to the optical fiber and the cessation of the supply of the laser beam to the optical fiber. The laser beam is emitted from the tip of the optical fiber under control by the control unit to generate bubbles at the tip of the optical fiber. The control unit stops the laser beam emitted from the tip of the optical fiber, causing the bubble to shrink. The contraction force of the bubble is applied between the optical fiber and the adjacent working member to bring the optical fiber closer to the working member. When the contraction force disappears due to the collapse of the bubble, the elastic restoring force of the optical fiber is used to move the optical fiber toward the side opposite to the working member, thereby causing the optical fiber to vibrate.

2. The laser irradiation device according to claim 1, wherein, The laser beam is used to treat the patient.

3. The laser irradiation device according to claim 1, wherein, It also has a dynamic detection unit for detecting the dynamics of the optical fiber. The control unit performs the following processing: Changing the pulse frequency of the pulsed laser beam; and The dynamic detection unit detects the dynamics of the optical fiber at each of the pulse frequencies, and the dynamics include at least the vibration amplitude of the front end of the optical fiber.

4. The laser irradiation device according to claim 3, wherein, The control unit performs the following processing: The resonant frequency of the optical fiber in the medium is determined based on the dynamics of the optical fiber; and The pulse frequency of the laser beam is set at the resonant frequency.

5. The laser irradiation device according to claim 4, wherein, The pulse frequency of the laser beam is 50Hz to 100Hz.

6. The laser irradiation device according to claim 4, wherein, The pulse frequency of the laser beam is 70Hz to 80Hz.

7. A laser treatment system, comprising: Optical fiber, which is placed in a liquid medium; A laser oscillator that supplies the optical fiber with a pulsed laser beam emitted from the tip of the optical fiber; and The control unit controls the emission of the pulsed laser beam generated by the laser oscillator. in, The control unit repeatedly controls the supply of the laser beam to the optical fiber and the cessation of the supply of the laser beam to the optical fiber. The laser beam is emitted from the tip of the optical fiber under control by the control unit to generate bubbles at the tip of the optical fiber. The control unit stops the laser beam emitted from the tip of the optical fiber, causing the bubble to shrink. The contraction force of the bubble is applied between the optical fiber and the adjacent working member to bring the optical fiber closer to the working member. When the contraction force disappears due to the collapse of the bubble, the elastic restoring force of the optical fiber is used to move the optical fiber toward the side opposite to the working member, thereby causing the optical fiber to vibrate.

8. The laser therapy system according to claim 7, wherein, The laser beam is used to treat the patient.

9. The laser therapy system according to claim 7, wherein, It also has a dynamic detection unit for detecting the dynamics of the optical fiber. The control unit performs the following processing: Changing the pulse frequency of the pulsed laser beam; and The dynamic detection unit detects the dynamics of the optical fiber at each of the pulse frequencies, and the dynamics include at least the vibration amplitude of the front end of the optical fiber.

10. The laser treatment system according to claim 9, wherein, The control unit performs the following processing: The resonant frequency of the optical fiber in the medium is determined based on the dynamics of the optical fiber; and The pulse frequency of the laser beam is set at the resonant frequency.

11. The laser treatment system according to claim 9, wherein, It also has: An image acquisition unit acquires an image including the front end of the optical fiber and the treatment object; and The display unit displays the image. The display unit shows the dynamics of the optical fiber as detected by the dynamic detection unit.

Images