A medical laser side-firing ablation surgical instrument and design method

Abstract

The application provides a medical laser side-emission ablation surgical instrument and a design method, and belongs to the field of surgical instruments. The medical laser side-emission ablation surgical instrument comprises a fiber connector, a soft sleeve coated fiber, a handle, a hard sleeve coated fiber and a light outlet end. The hard sleeve coated fiber comprises a fiber line composed of a fiber core and a cladding, a metal tube one, a metal tube two and a plastic tube which are sleeved on the periphery of the fiber line. The fiber line penetrates through the metal tube one, and the end of the fiber line is ground into an inclined plane. The plastic tube is coated on the outer layer of the metal tube one, and the length of the plastic tube is less than that of the metal tube one. The end of the metal tube one is sleeved with the metal tube two, the end of the metal tube two exceeds the end of the metal tube one to form a flared structure, and the light outlet end is connected to the fiber line and fixed by the flared structure. The side wall of the light outlet end is provided with a light outlet window, and the light outlet window is located on the acute side of the inclined plane structure of the end of the fiber line. The application theoretically designs the structure size of the side-emission light outlet end, and improves the handle, the flared end and other key components.

Description

Technical Field

[0001] This invention belongs to the field of surgical instruments, and particularly relates to a medical laser side-radiation ablation surgical instrument and its design method. Background Technology

[0002] Ablation surgical instruments using optical fibers as the primary laser delivery medium have been applied in minimally invasive laser ablation surgery. Because surgical methods based on these instruments offer numerous advantages in the treatment of diseases such as urinary tract stones, they can provide an effective alternative to traditional surgical treatments for some conditions. These ablation surgical instruments mainly include two types: direct-fire and side-fire. Side-fire ablation surgical instruments can meet specific surgical requirements in practice, allowing the delivered laser to be output laterally relative to the fiber optic axis, thus overcoming some limitations of direct-fire ablation instruments. Due to the unique application value of laser side-fire ablation surgical instruments, the development of this surgical instrument technology is of great significance.

[0003] The side-emitting end of the instrument is one of the key components, and its performance parameters directly affect the precise control of the emitted light field. Currently, proposed techniques for achieving side-guided light at the fiber optic output end mainly include adding micromirrors and grinding beveled surfaces to form mirrors. Among these, the method of directly grinding a micro-bevel on the fiber end face to form a mirror is widely used in side-emitting ablation surgical instruments due to its advantages of compact structure, simple processing, and low cost. However, the quantitative analysis of the actual emitted light field range of this side-emitting light field technology still needs further in-depth study, especially the relative positional relationship between the actual light field and the specific output end structure, which needs to be more precisely controlled to improve the final light field emission accuracy. Summary of the Invention

[0004] To overcome the aforementioned problems, this invention proposes a medical laser side-emitting ablation surgical instrument and its design method. For a specific lateral light-emitting end structure, by analyzing the optical field characteristics across the entire theoretical range of the inclined angle of the fiber optic cable's end face, a calculation method for the lateral emitted light field is proposed, thus providing a theoretical basis for the structural design of the light-emitting end. Simultaneously, improved implementation methods are proposed for key components such as the instrument's handle and the flared end of the metal tube.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A medical laser side-emission ablation surgical instrument includes an optical fiber connector, a soft-sleeved coated optical fiber, a handle, a hard-sleeved coated optical fiber, and an output end; the output port of the optical fiber connector is connected to one end of the handle through the soft-sleeved coated optical fiber, and the other end of the handle is connected to the output end through the hard-sleeved coated optical fiber; the laser enters from the input end of the optical fiber connector, passes sequentially through the soft-sleeved coated optical fiber, the handle, and the hard-sleeved coated optical fiber, and is finally output laterally through the output window of the output end;

[0007] The rigid sleeve-coated optical fiber includes an optical fiber line composed of an optical fiber core and its cladding, a first metal tube, a second metal tube, and a plastic tube sleeved around the optical fiber line; the optical fiber line passes through the first metal tube, and the end of the optical fiber line is ground into a bevel; the plastic tube covers the outer layer of the first metal tube and the length of the plastic tube is less than the length of the first metal tube, the first metal tube and the plastic tube constitute the rigid sleeve; the second metal tube is sleeved on the outer layer of the end of the first metal tube, and the end of the second metal tube extends beyond the end of the first metal tube to form a flared structure, the light-emitting end is connected to the optical fiber line and fixed by the flared structure; the side wall of the light-emitting end is provided with a light-emitting window, which is located on the acute angle side of the beveled structure at the end of the optical fiber line.

[0008] Preferably, the handle is a split, detachable structure, including an anti-bending component, a handle near-body component, and a handle far-body component; the anti-bending component is a snap-fit ​​structure with an optical fiber channel, the handle far-body component is a stepped shaft structure with an optical fiber channel, and the optical fiber channels of the anti-bending component and the handle far-body component are connected through the handle near-body component.

[0009] The handle's close-body component has a stepped channel running through both ends. The snap-fit ​​connection end of the anti-bending component passes through the small-diameter channel in the stepped channel of the handle's close-body component to achieve a snap-fit ​​connection. The small-diameter end of the handle's far-body component extends into the large-diameter interior of the stepped channel of the handle's close-body component to achieve a threaded connection. The soft sleeve in the fiber optic sheath is bonded and fixed to the non-snap-fit ​​connection end of the anti-bending component. The hard sleeve in the fiber optic sheath passes through the fiber optic channels inside the anti-bending component and the handle's far-body component in sequence.

[0010] Preferably, the optical fiber channel inside the small-diameter end of the handle remote component is widened into a stepped channel structure with the large diameter facing outward and the small diameter facing inward, and the hard sleeve tube wall of the hard sleeve tube covering the optical fiber located in the stepped channel structure of the handle remote component is provided with an exhaust hole.

[0011] Preferably, the soft-sleeved coated optical fiber and the hard-sleeved coated optical fiber share the same optical fiber line, and the soft-sleeved coated optical fiber is obtained by wrapping a soft material around the optical fiber line.

[0012] Preferably, the inclination angle of the inclined surface at the end of the optical fiber is in the range of (α2, α6), where:

[0013] α2=π / 2-arcsin(1 / n1) / 2-arcsin(n2 / n1) / 2

[0014] α6=arcsin(1 / n1) / 2+arcsin(n2 / n1) / 2

[0015] Where n1 and n2 are the refractive indices of the fiber core and cladding, respectively, and α2 and α6 are the critical values ​​of the tilt angle range of the inclined surface at the end of the fiber.

[0016] Preferably, the light-emitting end includes a U-shaped quartz tube and a U-shaped metal tube. The quartz tube is sleeved on the end of the optical fiber and positioned by the flared structure. The metal tube is sleeved on the outer layer of the quartz tube and fixed to the end of the optical fiber covered by the hard sleeve. The circumferential sidewall of the metal tube is provided with a light-emitting window.

[0017] The above-mentioned design method for medical laser side-emitting ablation surgical instruments includes the design of the light emission window size, and the steps are as follows:

[0018] (1) Define the intersection of the fiber core axis and the end slope as point O. Determine the maximum angle between the light rays transmitted in the fiber line and the fiber core axis based on the refractive index of the fiber core and cladding.

[0019] (2) When the light in the fiber core is incident on the inclined plane, for the upper edge light at the maximum angle, according to the law of reflection and refraction, the critical deviation of the maximum edge of the opening of the light-emitting window near the three ends of the metal tube relative to point O is obtained; similarly, for the lower edge light at the maximum angle, the critical deviation of the maximum edge of the opening of the light-emitting window far from the three ends of the metal tube relative to point O is obtained.

[0020] (3) Introduce the processing error of the tilt angle of the bevel at the end of the optical fiber, correct the critical deviation calculation formula in step (2), and calculate the actual critical deviation based on the correction result.

[0021] (4) Design the optical window based on the actual critical deviation size.

[0022] Preferably, the critical deviation of the maximum edge of the opening of the corrected light-emitting window relative to point O at the three ends of the metal tube is calculated as follows:

[0023]

[0024]

[0025] L 1max =d1 / (2tgα)+(d2-d1)tg(arcsin{n1sin[arcsin(n2 / n1)+2α] / n2}) / 2

[0026] +(d3-d2)tg(arcsin{n1sin[arcsin(n2 / n1)+2α] / n3}) / 2

[0027] +(d4-d3)tg(arcsin{n1sin[arcsin(n2 / n1)+2α]}) / 2

[0028] L 2max =d1 / (2tgα)-d1tg[arcsin(n2 / n1)-2α]

[0029] -(d2-d1)tg(arcsin{n1sin[arcsin(n2 / n1)-2α] / n2}) / 2

[0030] -(d3-d2)tg(arcsin{n1sin[arcsin(n2 / n1)-2α] / n3}) / 2

[0031] -(d4-d3)tg(arcsin{n1sin[arcsin(n2 / n1)-2α]}) / 2

[0032]

[0033] θ8=arcsin{n1sin[arcsin(n2 / n1)+2α]}

[0034] α2=π / 2-arcsin(1 / n1) / 2-arcsin(n2 / n1) / 2

[0035] α4=arcsin(n2 / n1) / 2

[0036] α5=π / 2-arcsin(n2 / n1) / 2

[0037] α6=arcsin(1 / n1) / 2+arcsin(n2 / n1) / 2

[0038] Where D1′ and D2′ are the critical deviations of the maximum edge of the corrected light output window relative to point O at the three ends of the metal tube, respectively; n1 and n2 are the refractive indices of the fiber core and cladding, respectively; α is the tilt angle of the fiber end face after polishing; +σ and -υ are the positive and negative tolerances of the fiber end face tilt angle α, respectively; d1 is the fiber core diameter; d2 is the fiber cladding diameter; d3 is the outer diameter of the quartz tube; d4 is the outer diameter of the three metal tubes; and θ8 is the refraction angle of the upper edge optical path at the interface between the quartz tube and the air. L is the angle of refraction at the interface between the quartz tube and the air along the lower edge of the optical path; 1maxL is the theoretical maximum value of the deviation of the point where the light ray emitted from the upper edge along the optical path intersects the three outer surfaces of the metal tube relative to point O, towards the three ends of the metal tube. 2max The theoretical maximum value of the deviation of the intersection point of the light ray emitted from the lower edge along the optical path and the three outer surfaces of the metal tube relative to point O in the direction away from the three ends of the metal tube is α2, α4, α5, and α6, which are key angles related to the range of values ​​of α.

[0039] Preferably, the actual critical distance between the left and right edges of the corrected light-emitting window is expressed as:

[0040]

[0041] Where D′ is the actual critical distance between the left and right edges of the corrected light output window.

[0042] Preferably, the inclination angle of the inclined surface at the end of the optical fiber simultaneously satisfies the conditions of preventing light from incident on the cladding inclined surface and the condition of total internal reflection by the inclined surface, namely:

[0043] α≤π / 2-arcsin{n1sin[arcsin(n2 / n1)+2α] / n2}

[0044] α≤arcsin(n2 / n1)-arcsin(1 / n1)

[0045] Where α is the tilt angle of the fiber end face after polishing; n1 and n2 are the refractive indices of the fiber core and cladding, respectively.

[0046] The beneficial effects of this invention are:

[0047] (1) The present invention achieves the opening expansion by superimposing a metal short tube at the end of the optical fiber covered by a hard sleeve, and the light-emitting end is positioned by closely adhering to the flared structure, which reduces the complexity brought about by the mechanical flaring of the traditional metal tube; and since the wall thickness of the metal short tube and the length of the flared transition zone are controllable, the positioning of the light-emitting end in the whole mechanical structure can be achieved more accurately.

[0048] (2) This invention proposes a design method for the size of the light output window of a medical laser side-emitting ablation surgical instrument. Through this design, the relative positional relationship between the actual light field and the specific light output end structure can be accurately controlled, thereby improving the light field emission accuracy and light output efficiency. Attached Figure Description

[0049] Figure 1 This is a schematic diagram of the basic structure of a medical laser side-emitting ablation surgical instrument proposed in this invention;

[0050] Figure 2 This is a cross-sectional view of the bending-resistant component;

[0051] Figure 3This is a cross-sectional view of the handle's near-body components;

[0052] Figure 4 This is a cross-sectional view of the handle's rear component;

[0053] Figure 5 This is an axial section view of the structure near the light-emitting end;

[0054] Figure 6 This is the side-emitting optical path diagram at the light output end;

[0055] Figure 7 The relationship between the key angle and n2 was obtained through simulation.

[0056] Figure 8 Obtained through simulation The relationship between α and α;

[0057] Figure 9 The relationship between Ω and α was obtained through simulation.

[0058] Figure 10 The relationship between η and ε is obtained through simulation;

[0059] Figure 11 L was obtained through simulation 1max / L 2max The relationship between α and α;

[0060] Figure 12 The relationship between L and α is obtained through simulation;

[0061] Figure 13 The relationship between ζ and ε was obtained through simulation.

[0062] Figure 14 The relationship between D1 / D2 and α is obtained through simulation.

[0063] Figure 15 The relationship between D′ and α is obtained through simulation. Detailed Implementation

[0064] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0065] The following is in conjunction with the appendix Figure 1-8 The embodiments of the present invention will be described in further detail below.

[0066] like Figure 1 As shown, the medical laser side-emission ablation surgical instrument proposed in this invention consists of five parts: an optical fiber connector, a soft-sleeved coated optical fiber, a handle, a hard-sleeved coated optical fiber, and a light-emitting end. The laser enters through the input end of the optical fiber connector, passes sequentially through the soft-sleeved coated optical fiber, the handle, and the hard-sleeved coated optical fiber, and is finally output laterally through the light-emitting window of the light-emitting end.

[0067] In one specific embodiment of the present invention, the handle is composed of three parts: an anti-bending component, a handle near-body component, and a handle far-body component. The handle as a whole is approximately cylindrical in structure and symmetrical about the central axis. Figure 2 This is an axial cross-sectional view of the anti-bending component of the handle. The anti-bending component is a snap-fit ​​structure with a fiber optic channel, which can prevent the fiber optic cable from bending. Figure 3 This is a cross-sectional view of the handle's near-body component. The handle's near-body component has a stepped channel running through both the front and rear ends. The smaller diameter end of the stepped channel is used to connect to the anti-bending component, and the larger diameter end of the stepped channel is used to connect to the handle's far-body component. Figure 4 This is a cross-sectional view of the handle's distal body component, which is a stepped shaft structure with an optical fiber channel.

[0068] The three components mentioned above are connected by mechanical fixing, and the fiber optic channels of the anti-bending component and the handle remote component are connected through the handle close component. Figure 2 The snap-fit ​​connection end (right end) of the component shown is inserted... Figure 3 The small-diameter channel (left end) in the stepped channel of the component shown achieves a snap-fit ​​connection; Figure 3 The inner side of the large-diameter channel (right end) in the stepped channel of the component and Figure 4 The outer side of the smaller diameter end (left end) of the component is threaded, by... Figure 4 Screw in at the left end of the component Figure 3 The right end of the component enables a threaded connection between the two. The soft sleeve in the soft-sleeved fiber is bonded and fixed to the non-clamping connection end of the bending-resistant component, and the hard-sleeved fiber passes through the fiber optic channels inside the bending-resistant component and the handle extension component in sequence. In this embodiment, the soft-sleeved fiber and the hard-sleeved fiber share the same fiber optic cable. The soft-sleeved fiber is obtained by wrapping a soft material, such as PVC plastic soft sleeve material, around the fiber optic cable. The inner diameter of the soft sleeve needs to be slightly larger than the outer diameter of the fiber optic cable.

[0069] The above method creatively enables the traditional handle of this type of device to be detachable. The advantage of this detachable handle is that during actual production and assembly, it is sometimes necessary to inspect internal defects in the handle, confirm the firmness of the connections between various internal components, check the bonding strength between the fiber optic flexible sleeve and the anti-bending component, and sometimes it is also necessary to clean the inside of the handle. These processes often require disassembling the handle. The multi-component combined handle used in this invention facilitates repeated installation and disassembly of the handle, improving the flexibility of the actual installation and manufacturing process.

[0070] Figure 3 and 4 An optical fiber with a metal rigid sleeve is inserted and fixed in the hollow middle section. To facilitate the release of heated gas from the sealed part at the ablation end during laser ablation, several small holes are made on the side of the rigid sleeve. The location of these small holes is... Figure 3 The hollowed-out part in the middle of the component and Figure 4 The left end of the component has two relatively large hollow sections with relatively large inner diameters. These positions are located in areas with a large internal space in the handle, facilitating the release of gas.

[0071] Figure 5 The image shows an axial cross-section near the optical output end. The fiber end face here undergoes a certain polishing process, resulting in an angle α between the end face and the central axis, where α is less than π / 2 rad. The selected axial cross-section coincides with the fiber meridional plane, which is perpendicular to the polished fiber end face. The rigid-coated optical fiber includes an optical fiber line composed of an optical fiber core and its cladding, a metal tube 1, a metal tube 2, and a plastic tube surrounding the optical fiber line; the light-emitting end includes a U-shaped quartz tube and a U-shaped metal tube 3; the optical fiber line passes through the metal tube 1, and the end of the optical fiber line is ground into a bevel; the plastic tube covers the outer layer of the metal tube 1, and the length of the plastic tube is less than the length of the metal tube 1; the metal tube 2 is fitted over the outer layer of the end of the metal tube 1, and the end of the metal tube 2 extends beyond the end of the metal tube 1 to form a flared structure; the quartz tube is fitted over the end of the optical fiber line and fixed by the flared structure; the metal tube 3 is fitted over the quartz tube and fixed to the end of the rigid-coated optical fiber; the circumferential sidewall of the metal tube 3 has a light-emitting window, which is located on the acute angle side of the beveled structure at the end of the optical fiber line. In this embodiment, a coating layer, a protective sheath, etc., can also be added outside the cladding of the optical fiber line.

[0072] Compared to the traditional method of flaring the end of metal tube 1, this invention uses adhesive to bond the opening of metal tube 1 to a metal tube 2 with a larger inner diameter, thereby enlarging the opening to accommodate the installation of other mechanical components. The left end of the quartz tube and the right end of the metal tube 2 are positioned by close contact.

[0073] This invention reduces the complexity of traditional mechanical flaring of metal tubes. At the same time, because this method uses a metal short tube 2 of a predetermined size to bond with the metal tube 1, the wall thickness at the flare and the length of the flare transition zone can be precisely controlled in practice. In addition, the smaller transition area between the metal tube 1 and the metal short tube 2 can more accurately position the quartz tube in the entire mechanical structure.

[0074] Figure 6 This is the side-projection optical path diagram of the axial section at the light-emitting end. The selected axial section is... Figure 5 The description is the same. Since the maximum axial light field distribution range is mainly related to the meridional rays in the meridional plane corresponding to the axial section, this invention only discusses the characteristics of the meridional rays in the aforementioned meridional plane, and proposes the critical deviation of the maximum edge of the light-emitting window near and away from the three ends of the metal tube relative to the intersection point (O point) of the central axis and the end face in the direction of the central axis, as well as the design scheme of the actual critical distance of the left and right edges of the light-emitting window.

[0075] In an optical fiber, the light rays that can be transmitted are contained within a certain conical area, and this cone has an upper edge and a lower edge. When the light rays from the upper and lower edges are incident on the end face, they will pass through different optical paths and eventually exit from the window. Figure 6 In this diagram, β is the angle between the upper and lower edge light rays and the central axis; θ1 and θ2 are the incident and reflection angles of the upper edge light ray at the interface between the fiber core and air, respectively; θ3 and θ4 are the incident and refraction angles of the upper edge light path at the interface between the fiber core and cladding, respectively; θ5 and θ6 are the incident and refraction angles of the upper edge light path at the interface between the fiber cladding and the quartz tube, respectively; and θ7 and θ8 are the incident and refraction angles of the upper edge light path at the interface between the quartz tube and air, respectively. arrive These are the incident angle and reflection angle of the lower edge light at the interface between the fiber core and the air; arrive These are the incident angle and the refraction angle at the interface between the fiber core and cladding, respectively, along the lower edge of the optical path. arrive These are the incident angle and the refraction angle at the interface between the optical fiber cladding and the quartz tube, respectively, along the lower edge of the optical path. arrive These are the incident angle and refraction angle of the lower edge light path at the interface between the quartz tube and the air; point O is the intersection of the central axis and the end face; point A is the intersection of the outgoing ray corresponding to the upper edge light and the outer surface of the metal tube 3; point B is the intersection of the outgoing ray corresponding to the lower edge light and the outer surface of the metal tube 3; the right boundary ray corresponds to the outgoing ray of the upper edge light, and this upper edge light is incident on the lower boundary of the end face of the fiber core; the left boundary ray corresponds to the outgoing ray of the lower edge light, and this lower edge light is incident on the upper boundary of the end face of the fiber core.

[0076] According to the total internal reflection theorem, the total internal reflection angle at the fiber core and cladding interface can be expressed as:

[0077] θ c1 =arcsin(n2 / n1) (1)

[0078] In the formula, n1 and n2 are the refractive indices of the fiber core and cladding, respectively. Therefore, the maximum angle β between the light rays propagating in the fiber and the fiber's central axis can be expressed as:

[0079] β=π / 2-arcsin(n2 / n1) (2)

[0080] Based on the typical parameters of n1 and n2 (e.g., n1 = 1.457, n2 = 1.440), we can obtain β < θ. c1 This invention assumes θ c1 Since θ and β satisfy the above relationship, θ c1 Satisfying π / 4 < θ c1 <π / 2, and β satisfies 0<β<π / 4. In this invention, for the incident angle and refraction angle of light at the transmission interface, it is defined that when the light turns towards the normal at an acute angle, clockwise rotation is positive and counterclockwise rotation is negative. The incident angle of the upper edge light at the interface between the fiber core and the air can be expressed as:

[0081] θ1=arcsin(n2 / n1)+α-π (3)

[0082] When α satisfies 0 < α ≤ β, according to equation (3), the range of θ1 is arcsin(n2 / n1) - π < θ1 ≤ -π / 2. This means that the upper edge light cannot directly reach the end face. Simultaneously, some light rays near the upper edge that could reach the end face, after being reflected by the end face, will be unable to pass through the interface between the fiber core and cladding due to total internal reflection, which will reduce power transmission efficiency. Therefore, to avoid the above situation, the range of α must satisfy β < α < π / 2.

[0083] The incident angle at the interface between the fiber core and cladding along the upper edge of the optical path can be expressed as:

[0084] θ3=π-arcsin(n2 / n1)-2α (4)

[0085] When the range of α must satisfy β < α < π / 2, it can be found that θ3 and θ c1 The relation satisfies |θ3|<θ c1 This indicates that light at the upper edge can pass through the interface between the fiber core and the cladding.

[0086] Similarly, the incident angle of the lower edge light at the interface between the fiber core and the air can be expressed as:

[0087]

[0088] The incident angle of the lower edge optical path at the interface between the fiber core and cladding can be expressed as:

[0089]

[0090] In order for the lower edge light to pass through the fiber core and cladding interface Must meet Therefore, α must satisfy 0 < α < θ c1 Combining the condition β < α < π / 2, we can conclude that α must satisfy β < α < θ. c1 The present invention will discuss the optical field characteristics within this scope.

[0091] The incident angle along the upper edge of the optical path at the interface between the fiber cladding and the quartz tube can be expressed as:

[0092] θ5=arcsin{n1sin[arcsin(n2 / n1)+2α] / n2} (7)

[0093] The angle of incidence along the upper edge of the optical path at the interface between the quartz tube and the air can be expressed as:

[0094] θ7=arcsin{n1sin[arcsin(n2 / n1)+2α] / n3} (8)

[0095] In the formula, n3 is the refractive index of the quartz tube.

[0096] The total internal reflection angle at the interface between the quartz tube and air can be expressed as:

[0097] θ c2 =arcsin(1 / n3) (9)

[0098] For the light from the upper edge to pass through the interface, θ7 must satisfy |θ7| < θ c2 Therefore, according to equations (8) and (9), α must satisfy π / 2-arcsin(1 / n1) / 2-arcsin(n2 / n1) / 2<α<π / 2+arcsin(1 / n1) / 2-arcsin(n2 / n1) / 2.

[0099] The angle of refraction along the upper edge of the light path at the interface between the quartz tube and the air can be expressed as:

[0100] θ8=arcsin{n1sin[arcsin(n2 / n1)+2α]} (10)

[0101] When the output light of the upper edge optical path exits to the right side of the normal, θ8 needs to satisfy θ8>0, therefore, α needs to satisfy π / 2-arcsin(1 / n1) / 2-arcsin(n2 / n1) / 2<α<π / 2-arcsin(n2 / n1) / 2; on the other hand, when the output light of the upper edge optical path exits to the left side of the normal, θ8 needs to satisfy θ8<0, therefore, α needs to satisfy π / 2-arcsin(n2 / n1) / 2<α<π / 2+arcsin(1 / n1) / 2-arcsin(n2 / n1) / 2; specifically, when the output light is perpendicular to the interface between the quartz tube and air, θ8 needs to satisfy θ8=0, therefore, α needs to satisfy α=π / 2-arcsin(n2 / n1) / 2.

[0102] The incident angle of the lower edge optical path at the interface between the fiber cladding and the quartz tube can be expressed as:

[0103]

[0104] The incident angle of the lower edge optical path at the interface between the quartz tube and air can be expressed as:

[0105]

[0106] In order for the lower edge light to pass through the interface, it is required to satisfy Therefore, according to formulas (9) and (12), α needs to satisfy arcsin(-1 / n1) / 2+arcsin(n2 / n1) / 2<α<arcsin(1 / n1) / 2+arcsin(n2 / n1) / 2.

[0107] The refraction angle of the lower edge optical path at the interface between the quartz tube and air can be expressed as:

[0108]

[0109] When the output light of the lower edge optical path exits to the left side of the normal, it is required to satisfy Therefore, α needs to satisfy arcsin(n2 / n1) / 2<α<arcsin(1 / n1) / 2+arcsin(n2 / n1) / 2; on the other hand, when the output light of the lower edge optical path exits to the right side of the normal, it is required to satisfy Therefore, α needs to satisfy arcsin(-1 / n1) / 2+arcsin(n2 / n1) / 2<α<arcsin(n2 / n1) / 2; specifically, when the output light is perpendicular to the interface between the quartz tube and air, it is required to satisfy Therefore, α must satisfy α=arcsin(n2 / n1) / 2.

[0110] According to equations (10) and (13), the divergence angle of the emitted beam along the central axis of the optical fiber can be expressed as:

[0111]

[0112] In the formula, Ω reflects the degree of divergence of the emitted beam. The expression for the derivative of Ω with respect to α is:

[0113]

[0114] When α is π / 4 rad, Ω' is 0. Therefore, the value of α corresponds to the extreme point of Ω.

[0115] On the other hand, the amount of light totally internally reflected at the fiber endface is one of the key factors in the final transmission efficiency. It depends on the total internal reflection angle at the fiber core-air interface, and this total internal reflection angle can be expressed as:

[0116] θ c3 =arcsin(1 / n1) (16)

[0117] For all light rays incident on the end face of an optical fiber to be totally internally reflected, the following condition must be met. Therefore, α must satisfy α≤arcsin(n2 / n1)-arcsin(1 / n1); conversely, when no ray incident on the fiber end face is totally internally reflected, the condition θ1>-θ is satisfied. c3 At this point, α satisfies α>π-arcsin(n2 / n1)-arcsin(1 / n1).

[0118] Based on the different ranges of α corresponding to the different optical path characteristics mentioned above, 10 key angles can be obtained, as shown in Table 1.

[0119] Key Angles in Table 1α

[0120] <![CDATA[α0]]> β <![CDATA[α5]]> <![CDATA[π / 2-arcsin(n2 / n1) / 2]]> <![CDATA[α1]]> <![CDATA[arcsin(-1 / n1) / 2+arcsin(n2 / n1) / 2]]> <![CDATA[α6]]> <![CDATA[arcsin(1 / n1) / 2+arcsin(n2 / n1) / 2]]> <![CDATA[α2]]> <![CDATA[π / 2-arcsin(1 / n1) / 2-arcsin(n2 / n1) / 2]]> <![CDATA[α7]]> <![CDATA[π-arcsin(n2 / n1)-arcsin(1 / n1)]]> <![CDATA[α3]]> <![CDATA[arcsin(n2 / n1)-arcsin(1 / n1)]]> <![CDATA[α8]]> <![CDATA[π / 2+arcsin(1 / n1) / 2-arcsin(n2 / n1) / 2]]> <![CDATA[α4]]> <![CDATA[arcsin(n2 / n1) / 2]]> <![CDATA[α9]]> <![CDATA[θ c1 ]]>

[0121] The change in the light emission angle with α causes fluctuations in the coverage area of ​​the emitted beam, which directly affects the ablation range. Generally, during ablation, the outer surface of the metal tube 3 is very close to the target tissue; therefore, this discussion focuses on the variation of the coverage area of ​​the emitted beam along the fiber's central axis on this surface with α. The offset of point A relative to point O along the central axis can be expressed as:

[0122] L1=m+(d1 / 2-mtgα)tgθ3+(d2-d1)tgθ5 / 2+(d3-d2)tgθ7 / 2+(d4-d3)tgθ8 / 2 (17)

[0123] In the formula, m is the offset of the incident point of the upper edge ray at the end face of the optical fiber relative to point O in the direction of the central axis. Here, positive and negative m correspond to the incident point being to the right and left of point O, respectively; positive and negative L1 correspond to point A being to the right and left of point O, respectively.

[0124] Specifically, when the incident point of the upper edge light is at the lower boundary of the end face of the fiber core, m can be expressed as:

[0125] m=d1 / (2tgα) (18)

[0126] In this case, the maximum value of L1 can be expressed as:

[0127] L 1max =d1 / (2tgα)+(d2-d1)tg(arcsin{n1sin[arcsin(n2 / n1)+2α] / n2}) / 2

[0128] +(d3-d2)tg(arcsin{n1sin[arcsin(n2 / n1)+2α] / n3}) / 2

[0129] +(d4-d3)tg(arcsin{n1sin[arcsin(n2 / n1)+2α]}) / 2(19)

[0130] The offset of point B relative to point O along the central axis can be expressed as:

[0131]

[0132] In the formula, n is the offset of the upper edge ray incident point on the fiber end face relative to point O along the central axis. Here, positive and negative n correspond to the incident point being to the left and right of point O, respectively; L2 corresponds to positive and negative L2 corresponding to point B being to the left and right of point O, respectively. In particular, when the incident point of the lower edge ray is at the upper boundary of the fiber core end face, n can be expressed as:

[0133] n=d1 / (2tgα) (21)

[0134] In this case, the maximum value of L2 can be expressed as:

[0135] L 2max =d1 / (2tgα)-d1tg[arcsin(n2 / n1)-2α]

[0136] -(d2-d1)tg(arcsin{n1sin[arcsin(n2 / n1)-2α] / n2}) / 2

[0137] -(d3-d2)tg(arcsin{n1sin[arcsin(n2 / n1)-2α] / n3}) / 2

[0138] -(d4-d3)tg(arcsin{n1sin[arcsin(n2 / n1)-2α]}) / 2(22)

[0139] According to equations (19) and (22), the distance between the left and right edges of the output light field distributed on the outer surface of the metal tube 3 can be expressed as:

[0140] L = L 1max +L 2max (twenty three)

[0141] Table 1 summarizes 10 key angles of α.

[0142] Clearly, the above angles vary with refractive indices n1 and n2. Figure 7 The relationship between the critical angle and n2 was obtained through simulation. The fiber core refractive index n1 was set to 1.457; the fiber cladding refractive index n2 was set to range from 1.409 to 1.452. The numerical aperture (NA) of the fiber corresponding to the above parameters ranged from 0.37 to 0.12. It can be observed that there exists a value n for n2. 20 When n2 is less than n 20 When n2 is greater than n, the critical angles of α satisfy α0 < α1 < α2 < α3 < α4 < α5 < α6 < α7 < α8 < α9, while when n2 is greater than n 20 When α is constant, the key angles satisfy α0 < α1 < α2 < α3 < α4 < α5 < α7 < α6 < α8 < α9. By solving α6 = α7, n... 20 It can be represented as:

[0143] n 20 =n1sin[2π / 3-arcsin(1 / n1)] (24)

[0144] According to equation (24), when n1 = 1.457, n 20 Approximately 1.418. Based on the aforementioned relationship between the key angles, in order for all light rays transmitted in the optical fiber to exit from the side, α should satisfy α2 < α < α6. It can be observed that α2 and α6 decrease and increase respectively with increasing n2, which means that reducing the numerical aperture is beneficial to increasing the range of α. The key angle α3 increases with increasing n2, which means that reducing the numerical aperture is also beneficial to increasing the range of α that ensures all light rays undergo total internal reflection at the end face.

[0145] Within the range of α2 < α < α6, further subdivisions can be made to obtain different optical field characteristics corresponding to different subdivision ranges. Table 2 shows the 6 and 7 different optical field characteristics that exist when n2 ≤ 1.418 and n2 > 1.418, respectively. It can be found that when n2 ≤ 1.418, there will always be some light that is totally reflected by the end face; however, when n2 > 1.418, once α increases to greater than α7, there will be no light that is totally reflected by the end face. Since this situation will severely reduce the transmission efficiency, it needs to be avoided. Although this problem can be solved by coating the end face, this will increase the complexity and cost of the manufacturing process.

[0146] In practice, the required overall radiation angle of the output beam varies in different application scenarios. Clearly, the angle of each output beam lies between the angles of the upper and lower edge output beams. Therefore, according to Table 2, by selecting different suitable ranges for α, different overall radiation angles of the emitted beam can be clearly achieved.

[0147] Table 2. Optical field characteristics of α under different range conditions

[0148]

[0149] When the range of α is designed to be α2 < α < α4, all output rays are deflected to the right of their respective normals. In this case, the entire emitted beam is deflected towards the distal end of the instrument. Specifically, to improve transmission efficiency, α is sometimes designed to be in the range α2 < α ≤ α3, causing total internal reflection at the end face. In this case, the entire emitted beam will always be deflected in the aforementioned direction. On the other hand, when the range of α is designed to be α5 < α < α6, all output rays are deflected to the left of their respective normals. Therefore, the entire emitted beam will be deflected away from the distal end of the instrument. Furthermore, when the range of α is designed to be α4 < α < α5, a portion of the output rays are deflected to the left of their respective normals, while the remaining rays are deflected to the right of their respective normals. This means the entire beam is divided into two parts, and these two parts are deflected towards the distal end of the instrument, respectively. Specifically, when α = π / 4 rad (e.g., ... Figure 7 As shown, this angle is included in the range α4 < α < α5, and the entire emitted beam will be symmetrically distributed in the two directions mentioned above.

[0150] According to equations (10) and (13), Figure 8 Obtained through simulation The relationship between α and δ. Here, the range of α is set to vary from α² + δ to α⁶ - δ, where δ is set to 10. -3rad, thus satisfying α2 < α < α6; the refractive index n2 of the fiber cladding is set to 1.409, 1.440, and 1.452, corresponding to numerical apertures of 0.37, 0.22, and 0.12, respectively. It can be observed that θ8 and Generally, it increases with increasing numerical aperture. For a given numerical aperture, θ8 and Both decrease as α increases, and θ8 decreases more rapidly when α is less than a certain value. The rate of decrease is faster when α is greater than a certain value. Furthermore, according to equations (10) and (13), when α = π / 4 rad, This corresponds to an axisymmetric outgoing beam.

[0151] According to equation (14), Figure 9 The relationship between Ω and α is obtained through simulation. It can be found that Ω generally increases with the increase of numerical aperture. For a certain numerical aperture, when α = π / 4 rad (according to equation (15), corresponding to the extreme value of Ω), Ω reaches its minimum value, which corresponds to the numerical aperture and can be expressed as:

[0152] Ω0=2arcsin{n1cos[arcsin(n2 / n1)]} (25)

[0153] When α is less than π / 4 rad, Ω decreases as α increases, and the rate of decrease is faster when α is less than a certain value; when α is greater than π / 4 rad, Ω increases as α increases, and the rate of decrease is faster when α is greater than a certain value. Therefore, in order to prevent Ω from becoming too large and causing the output beam to diverge excessively, α needs to be limited to a certain range. When α deviates from π / 4 rad by ε, according to equation (14), Ω can be expressed as:

[0154] Ω=arcsin{n1cos[arcsin(n2 / n1)+2ε]}+arcsin{n1cos[2ε-arcsin(n2 / n1)]}(26)

[0155] Therefore, when α deviates from π / 4 rad, the growth rate of Ω can be expressed as:

[0156] η=(Ω-Ω0) / Ω0

[0157] =(arcsin{n1cos[arcsin(n2 / n1)+2ε]}+arcsin{n1cos[2ε-arcsin(n2 / n1)]}

[0158] -2arcsin{n1cos[arcsin(n2 / n1)]}) / (2arcsin{n1cos[arcsin(n2 / n1)]})(27)

[0159] According to equation (27), Figure 10 The relationship between η and ε is obtained through simulation. It can be observed that as |ε| increases, η grows faster for larger numerical apertures. Here, it is assumed that η needs to be limited to a value less than η. t When η t When set to 5%, for numerical apertures of 0.37, 0.22, and 0.12, |ε| needs to be controlled to be less than 0.1258, 0.1350, and 0.1385, respectively. Therefore, a smaller numerical aperture corresponds to a larger range of α, limiting the growth rate of Ω to a certain range. When the numerical apertures are 0.37, 0.22, and 0.12, α3 is 0.5570, 0.6614, and 0.7315 rad, respectively. When α is set to the above values ​​of α3, η is 28.29%, 4.12%, and 0.68%, respectively. Therefore, for the case where all light is totally internally reflected at the fiber endface, η is less than 5% when the numerical aperture is 0.22 or 0.12; however, when the numerical aperture is 0.37, η increases to greater than 5%.

[0160] According to equations (19) and (22), Figure 11 L was obtained through simulation 1max / L 2max The relationship between L and α. Here, the refractive index n3 of the quartz tube is set to 1.457, the fiber core diameter d1 is set to 0.6 mm, the fiber cladding diameter d2 is set to 0.66 mm, the outer diameter of the quartz tube d3 is set to 1.65 mm, and the outer diameter of the metal tube 3 d4 is set to 2 mm. It can be observed that L 1max and L 2max Generally, it increases with increasing numerical aperture. When α is at a value close to π / 4 rad, α... e At that time, L 1max =L 2max , and α e It increases as the numerical aperture decreases. For a given numerical aperture, L 1max and L 2max The values ​​decrease and increase respectively as α increases. In particular, when α is less than a certain value, L... 1max The rate of decrease is relatively fast; on the other hand, when α is greater than a certain value, L... 1max The rate of increase is relatively fast.

[0161] According to equation (23), Figure 12 The relationship between L and α was obtained through simulation. It can be observed that L generally increases with increasing numerical aperture. When α is at a value close to π / 4 rad... m When L reaches its minimum value, this minimum value can be expressed as:

[0162] L0=L(α=α m (28)

[0163] Based on numerical simulation results, when the numerical aperture is 0.37, 0.22, and 0.12, α m The values ​​are 0.7771, 0.7809, and 0.7835 rad, respectively. Therefore, α... m It increases as the numerical aperture decreases. For a given numerical aperture, when α is less than α... m When α increases, L decreases, and the rate of decrease is faster when α is less than a certain value; on the other hand, when α is greater than α... m When α increases, L increases with increasing α, and when α is greater than a certain value, the rate of increase of L is faster.

[0164] When α is relative to α m When deviating from ε, according to equation (23), L can be expressed as:

[0165] L=L(α=α m+ ε) (29)

[0166] Therefore, the rate of increase of L can be expressed as:

[0167] ζ=(L-L0) / L0 (30)

[0168] According to equation (30), Figure 13 The relationship between ζ and ε was obtained through simulation. It can be observed that for larger numerical apertures, ζ increases more rapidly when ε deviates from 0. Here, it is assumed that ζ needs to be controlled to be less than ζ. t When ζ t When α is set to 5%, for numerical apertures of 0.37, 0.22, and 0.12, the range of ε needs to be controlled within -0.1036 < ε < 0.1051, -0.1171 < ε < 0.1176, and -0.1284 < ε < 0.1285, respectively. Therefore, a smaller numerical aperture corresponds to a larger range of α, limiting the growth rate of L to a certain range. When α is set to α3, ζ is 44.74%, 5.22%, and 0.78% for different numerical apertures of 0.37, 0.22, and 0.12, respectively. Therefore, for the case where all light is totally internally reflected at the fiber end face, η can be limited to less than 5% when the numerical aperture is 0.12; however, when the numerical aperture is 0.37 or 0.22, η increases to greater than 5%.

[0169] To prevent the output light from being blocked, the size of the light-emitting window boundary on metal tube 3 needs to be designed according to the range of the light field distribution. Based on the above analysis, different values ​​of α will cause the output boundary light to deflect towards different sides of the normal. Since the wall of metal tube 3 has a certain thickness, according to geometric relationships, the expression for the size of the light-emitting window boundary will differ when the output boundary light deflects towards different sides of the normal. Considering the above factors, the minimum offset of the right boundary of the light-emitting window relative to point O in the direction of the central axis can be expressed as:

[0170]

[0171] Meanwhile, the minimum offset of the left boundary of the light-emitting window relative to point O along the central axis can be expressed as:

[0172]

[0173] According to equations (31) and (32), Figure 14 The relationship between D1 / D2 and α was obtained through simulation. It can be observed that D1 and D2 decrease and increase respectively as α increases. Compared to... Figure 11 The simulation results show that the overall variation characteristics of D1 / D2 are similar to those of L. 1max / L 2max Similarly, for the corresponding set of curves, there exists a common value of α, and the curves are steeper before and after this value; however, when α is greater than α5, D1 is steeper than L. 1max It will be slightly larger, and when α is less than α4, D2 compared to L 2max It will be slightly larger, and this characteristic can be obtained from equations (31) and (32).

[0174] In practice, there will be machining tolerances for the angle α after grinding. Here, the positive and negative tolerances of α are defined as +σ and -υ, respectively. When considering machining tolerances, in order to ensure that the output light is not blocked, according to... Figure 14 The monotonicity of D1 and D2 shown can be expressed as follows: The actual value of D1 can be expressed as:

[0175]

[0176] The actual value of D2 can be expressed as:

[0177]

[0178] Here, to ensure that the actual α is within the range of α2 < α < α6, this designed range of α is further restricted to α2 + υ < α < α6 - σ. Therefore, the actual critical distance between the left and right edges of the light-emitting window can be expressed as:

[0179]

[0180] In practice, the distance between the left and right edges of the light-emitting window should be as close as possible to -′ while ensuring it is not less than D′. This is to better shield the reflected light from the ablated tissue. According to equation (35), Figure 15 The relationship between d′ and α is obtained through simulation. Here, the positive tolerance +σ and the negative tolerance -υ are set to +2×10. -4 and -2×10 -4 rad; the range of α is set to vary from α² + δ + υ to α⁶ - δ - σ, where δ is set to 10. -3 rad, thus satisfying α² + υ < α < α⁶ - σ. Compared to Figure 12 The simulation results show that the overall variation characteristics of D′ are similar to those of L. D′ also has a minimum value when α is close to π / 4 rad. However, D′ is slightly larger than L, and when α is less than α4 or greater than α5, that is, when all the output rays are distributed on the same side of their respective normals, the curve corresponding to D′ is significantly steeper.

[0181] The above examples are merely specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments and many variations are possible. All variations that can be directly derived or conceived by those skilled in the art from the disclosure of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A design method for a medical laser side-radiation ablation surgical instrument, characterized in that, The medical laser side-emission ablation surgical instrument includes an optical fiber connector, a soft-sleeved coated optical fiber, a handle, a hard-sleeved coated optical fiber, and an output end; the output port of the optical fiber connector is connected to one end of the handle through the soft-sleeved coated optical fiber, and the other end of the handle is connected to the output end through the hard-sleeved coated optical fiber; the laser enters from the input end of the optical fiber connector, passes sequentially through the soft-sleeved coated optical fiber, the handle, and the hard-sleeved coated optical fiber, and is finally output from the output window of the output end; The rigid-coated optical fiber includes an optical fiber line composed of an optical fiber core and its cladding, a first metal tube, a second metal tube, and a plastic tube surrounding the optical fiber line; the optical fiber line passes through the first metal tube, and the end of the optical fiber line is ground into a bevel; the plastic tube covers the outer layer of the first metal tube, and the length of the plastic tube is less than the length of the first metal tube, the first metal tube and the plastic tube constitute the rigid sleeve; the second metal tube is fitted outside the end of the first metal tube, and the end of the second metal tube extends beyond the end of the first metal tube to form a flared structure, the light-emitting end is connected to the optical fiber line and fixed by the flared structure; the side wall of the light-emitting end is provided with a light-emitting window, which is located on the acute angle side of the beveled structure at the end of the optical fiber line. The light-emitting end includes a U-shaped quartz tube and a U-shaped metal tube. The quartz tube is sleeved on the end of the optical fiber and positioned by the flared structure. The metal tube is sleeved on the outer layer of the quartz tube and fixed to the end of the optical fiber covered by the hard sleeve. The circumferential sidewall of the metal tube has a light-emitting window. The design method includes the design of the light-emitting window size, and the steps are as follows: (1) Define the intersection of the fiber core axis and the end slope as point O. Determine the maximum angle between the light transmitted in the fiber line and the fiber core axis based on the refractive index of the fiber core and cladding. (2) When the light in the fiber core is incident on the inclined plane, for the upper edge light at the maximum angle, according to the law of reflection and refraction, the critical deviation of the maximum edge of the opening of the light-emitting window near the three ends of the metal tube relative to point O is obtained; similarly, for the lower edge light at the maximum angle, the critical deviation of the maximum edge of the opening of the light-emitting window far from the three ends of the metal tube relative to point O is obtained. (3) Introduce the processing error of the tilt angle of the inclined surface at the end of the optical fiber line, correct the critical deviation calculation formula in step (2), and calculate the actual critical deviation based on the correction result. (4) Design the optical window according to the actual critical deviation size.

2. The design method of the medical laser side-emitting ablation surgical instrument according to claim 1, characterized in that, The formula for calculating the critical deviation of the maximum edge of the light-emitting window relative to point O at the three ends of the metal tube (near and far from the ends) after modification is as follows: ； ； ； ； ； ； ； ； ； ； in, and d1, n2, and n3 are the critical deviations of the maximum edge of the opening of the corrected light-emitting window relative to point O at the three ends of the metal tube, respectively; n1, n2, and n3 are the refractive indices of the fiber core, cladding, and quartz tube, respectively; α is the tilt angle of the fiber end face after polishing; +σ and –υ are the positive and negative tolerances of the fiber end face tilt angle α, respectively; d1 is the diameter of the fiber core; d2 is the diameter of the fiber cladding; d3 is the outer diameter of the quartz tube; d4 is the outer diameter of the three ends of the metal tube; θ8 is the refraction angle of the upper edge of the optical path at the interface between the quartz tube and air; φ8 is the refraction angle of the lower edge of the optical path at the interface between the quartz tube and air; L 1max L is the theoretical maximum value of the deviation of the point where the light ray emitted from the upper edge along the optical path intersects the three outer surfaces of the metal tube relative to point O, towards the three ends of the metal tube. 2max The theoretical maximum value of the deviation of the intersection point of the light ray emitted from the lower edge along the optical path and the three outer surfaces of the metal tube relative to point O in the direction away from the three ends of the metal tube is α2, α4, α5, and α6, which are key angles related to the range of values ​​of α.

3. The design method of the medical laser side-emitting ablation surgical instrument according to claim 2, characterized in that, The actual critical distance between the left and right edges of the corrected light output window is expressed as follows: ； in, This represents the actual critical distance between the left and right edges of the corrected light-emitting window.

4. The design method of the medical laser side-emitting ablation surgical instrument according to claim 1, characterized in that, The tilt angle of the inclined surface at the end of the optical fiber simultaneously satisfies the conditions for preventing light from incident on the cladding inclined surface and for total internal reflection by the inclined surface, namely: ； ； Where α is the tilt angle of the fiber end face after polishing; n1 and n2 are the refractive indices of the fiber core and cladding, respectively.

5. The design method of the medical laser side-emitting ablation surgical instrument according to claim 1, characterized in that, The handle is a split, detachable structure, including an anti-bending component, a handle near-body component, and a handle far-body component; the anti-bending component is a snap-fit ​​structure with an optical fiber channel, and the handle far-body component is a stepped shaft structure with an optical fiber channel; the optical fiber channels of the anti-bending component and the handle far-body component are connected through the handle near-body component. The handle's close-body component has a stepped channel running through both ends. The snap-fit ​​connection end of the anti-bending component passes through the small-diameter channel in the stepped channel of the handle's close-body component to achieve a snap-fit ​​connection. The small-diameter end of the handle's far-body component extends into the large-diameter interior of the stepped channel of the handle's close-body component to achieve a threaded connection. The soft sleeve in the fiber optic cable is bonded and fixed to the non-snap-fit ​​connection end of the anti-bending component. The hard sleeve in the fiber optic cable passes through the fiber optic channels inside the anti-bending component and the handle's far-body component in sequence.

6. The design method of the medical laser side-emitting ablation surgical instrument according to claim 5, characterized in that, The optical fiber channel inside the small-diameter end of the handle remote component is widened into a stepped channel structure with the large diameter facing outward and the small diameter facing inward. The hard sleeve tube wall of the hard sleeve tube covering the optical fiber located in the stepped channel structure of the handle remote component has an exhaust hole.

7. The design method of the medical laser side-emitting ablation surgical instrument according to claim 1 or 5, characterized in that, The soft-sleeved and hard-sleeved optical fibers share the same optical fiber line, and the soft-sleeved optical fiber line is obtained by wrapping a soft material around the optical fiber line.

8. The design method of the medical laser side-emitting ablation surgical instrument according to claim 1, characterized in that, The inclination angle of the inclined surface at the end of the optical fiber ranges from (α2, α6), where: ； ； Where n1 and n2 are the refractive indices of the fiber core and cladding, respectively, and α2 and α6 are the critical values ​​of the tilt angle range of the inclined surface at the end of the fiber.

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