An intraocular micro-force sensing device and optical path connection system

Abstract

An intraocular micro-force sensing device and its optical path connection system are disclosed. The intraocular micro-force sensing device includes: a fiber Bragg grating (FBG) sensor array and an instrument sleeve; each FBG in the FBG sensor array is bonded to the instrument sleeve; wherein the number of FBGs in the FBG sensor array (1) is greater than or equal to 3, and the layout of the FBG sensor array on the instrument sleeve satisfies a preset temperature interference separation condition, which includes: the sum of the displacements of all FBG sensors to the x-axis is 0, and the sum of the displacements of all FBG sensors to the y-axis is 0. Thus, without the need for an additional temperature sensor, the force and temperature effects are separated directly through the statistical characteristics of the sensor array, significantly simplifying the temperature compensation process and improving the problems of large size and temperature interference in the field of intraocular micro-force sensing.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to an intraocular micro-force sensing device and optical path connection system. Background Technology

[0002] As ophthalmic surgery develops towards minimally invasive and precise techniques (such as subretinal injection and complex vitreoretinal surgeries like epiretinal membrane peeling), precise sensing of the contact force between surgical instruments and ocular tissues (such as the cornea, iris, and retina) has become a key technology for improving surgical safety and efficacy. For example, the vitrectomy tip needs to maintain a slight contact with the retina (usually at the submillinew level). Excessive contact force may cause retinal tears, while insufficient force may fail to effectively remove diseased tissue.

[0003] Fiber Bragg grating (FBG) sensors have attracted much attention in the field of biomedical sensing due to their advantages such as small size and high sensitivity. However, the wavelength changes of FBG are affected by both temperature (thermal expansion, thermo-optic effect) and force (strain), generally requiring the use of additional temperature sensors for measurement and temperature compensation. This increases the system complexity and instrument size, making it difficult to adapt to minimally invasive intraocular scenarios.

[0004] Therefore, how to provide an intraocular micro-force sensing device to improve the temperature interference problem in the field of intraocular micro-force sensing is a key research topic for those skilled in the art. Summary of the Invention

[0005] In a first aspect, this application provides an intraocular micro-force sensing device, comprising: a fiber Bragg grating (FBG) sensor array and an instrument sleeve; each FBG in the FBG sensor array is adhered to the instrument sleeve, the instrument sleeve being used to hold one or more flexible surgical instruments, and the FBG sensor array achieving in-situ measurement of the contact force between the surgical instruments and the eye tissue by sensing the deformation of the instrument sleeve due to contact with eye tissue; wherein, the number of FBGs in the FBG sensor array is greater than or equal to 3, and the arrangement of the FBG sensor array on the instrument sleeve satisfies a preset temperature interference separation condition, the preset temperature interference separation condition including: the sum of the displacements of all FBG sensors to the x-axis. =0, and the sum of the displacements of all FBG sensors to the y-axis. The value is 0, where n is the total number of FBG sensors, and the centers of the x-axis and y-axis are the geometric centers of the instrument cannula.

[0006] The intraocular microforce sensing device provided in this application addresses the issue of large size in the field of intraocular microforce sensing by combining sub-millimeter-scale miniaturized FBG sensors with a flexible sheath, achieving low invasiveness and high deformation transmission efficiency. Furthermore, the device features at least three FBG sensors arranged to meet preset temperature interference separation conditions. This eliminates the need for additional temperature sensors, directly utilizing the statistical characteristics of the sensor array to separate force and temperature effects, significantly simplifying the temperature compensation process, mitigating temperature interference, and enhancing measurement real-time performance and reliability.

[0007] In some possible implementations, the instrument cannula is used to attach one or more of the following instruments: surgical needles, surgical forceps, surgical hooks, and light guide pens.

[0008] Using this approach, this solution proposes a universal integrated framework of "FBG sensor + instrument cannula + surgical instruments," with the FBG sensor and cannula as basic components, adaptable to various instruments such as surgical needles, forceps, surgical hooks, and light guide pens. This "modular + universal" design significantly reduces the development and maintenance costs of the multi-instrument force sensing system for surgical robots.

[0009] In some possible implementations, the instrument cannula includes a single-cannula design, with the FBG sensor array adhered to the outer wall of the instrument cannula; if the instrument fitted by the instrument cannula is not a surgical hook or a light guide pen, the single-cannula design also has a through hole for the injection needle to flow fluid or for installing detachable components; if the instrument fitted by the instrument cannula is a surgical hook or a light guide pen, the single-cannula design does not include a through hole.

[0010] In some possible implementations, the instrument cannula includes a dual-cannula scheme, comprising an outer cannula and an inner cannula, the outer cannula enclosing the inner cannula, and the FBG sensor array being attached to the outside of the inner cannula.

[0011] This dual-cannula design isolates the instrument surface from friction, protecting the FBG from mechanical damage. The spatial isolation provided by the outer cannula also reduces direct interference from the external environment (such as tissue fluid and blood) on the FBG, thereby improving the stability of force perception.

[0012] In application, the two schemes can be flexibly switched (the single-cannula scheme can be switched to the double-cannula scheme by adding an outer cannula, and the double-cannula scheme can be switched to the single-cannula scheme by removing the outer cannula, or both single-cannula and double-cannula devices can be selected as backups). In scenarios where the required volume is as small as possible, the single-cannula scheme is used; in scenarios where high sensitivity and accuracy of measurement are required, the double-cannula scheme is used. This allows the instrument to adapt to complex surgical environments (such as the narrow space under minimally invasive endoscopy) while ensuring high sensitivity of force measurement, thus meeting diverse needs.

[0013] In some possible implementations, when the instrument fitted by the instrument sheath is not a surgical hook or a light guide pen, the inner sheath has a pre-drilled hole for the injection needle to flow fluid or for installing detachable components; when the instrument fitted by the instrument sheath is a surgical hook or a light guide pen, the inner sheath does not include a through-hole design. This optimizes the adaptable structure and meets diverse needs.

[0014] In some possible implementations, the intraocular microforce sensing device is connected to a contact force calculation module. The contact force calculation module is used to eliminate the influence of temperature wavelength change based on the difference between the total wavelength change and the average wavelength change of the first FBG, and obtain the deformation wavelength change corresponding to the first FBG. The contact force F between the surgical instrument and the eye tissue is calculated based on the deformation wavelength change corresponding to the first FBG. The average wavelength change is the average of the sum of the wavelength differences of all FBGs, and the first FBG is any one of the FBGs in the FBG sensor array.

[0015] This method completely eliminates temperature interference by calculating the difference between the wavelength change of a single FBG and the average wavelength change, simplifying the temperature compensation process and improving the temperature interference problem.

[0016] In some possible implementations, the contact force calculation module is specifically used to calculate the contact force F between the surgical instrument and the eye tissue based on Formula 5, wherein Formula 5 is obtained based on the following derivation process: the strain at the i-th FBG The relationship between the force and the applied force F satisfies the following formula 1:

[0017]

[0018] Wherein, F represents the contact force at the end of the instrument cannula. Where M is the distance from the center of the FBG grid region to the end of the instrument cannula, and E is the torque at the center of the FBG grid region when the end of the instrument cannula is subjected to a contact force F. Let be the distance from the i-th FBG to the neutral plane of the flexible cantilever of the casing, and I be the moment of inertia of the casing section.

[0019] Wavelength change of the i-th FBG Caused by both deformation and temperature, it satisfies the following formula:

[0020]

[0021] in, This indicates the amount of change in the feedback wavelength caused by deformation. This indicates the amount of change in the feedback wavelength caused by temperature changes. Let i be the initial feedback wavelength of the i-th FBG. The elastic coefficient is 1. The coefficient of thermal expansion is... Thermo-optic coefficient, This represents the change in temperature.

[0022] Combining Formula 1 and Formula 2, we obtain the following Formula 3:

[0023]

[0024] Because the layout of the FBG sensor array satisfies If the average wavelength change caused by temperature is only related to temperature, then the following formula 4 holds:

[0025]

[0026] Combining formulas 3 and 4, we obtain formula 5:

[0027]

[0028] In some possible implementations, the contact force calculation module is also used to determine the maximum force error based on error requirements. Determine the critical wavelength change using the following formula. :

[0029]

[0030] like If the measurement accuracy is greater than that of the demodulator, the contact force calculation module determines that the maximum force measurement error of the FBG sensor is less than or equal to the accuracy of the demodulator. To meet the accuracy requirements; if If the measurement accuracy is less than or equal to that of the demodulator, the contact force calculation module will adjust accordingly. , E, I or The value of increases So that The measurement accuracy is greater than that of the demodulator, ensuring that the measurement is feasible.

[0031] Using this method, this scheme addresses the theoretical error. It is directly related to the actual capabilities of the demodulator, avoiding the contradiction of high theoretical accuracy but hardware inability to achieve it, and enabling error pre-assessment before measurement to avoid invalid data acquisition due to unreasonable parameters, thereby improving measurement efficiency.

[0032] In some possible implementations, the aforementioned intraocular microforce sensing device is applied to an optical path connection system. In this system, the output signal of each FBG in the FBG sensor array is uniformly transmitted to an optical fiber coupler via an optical fiber. The optical fiber coupler is connected to a fiber optic grating demodulator. The fiber optic grating demodulator is used to emit broadband light to the optical fiber coupler and detect the wavelength difference between each FBG. It also transmits the wavelength difference data to a host computer via an Ethernet cable. The host computer is used to calculate the contact force between the surgical instruments and the ocular tissue.

[0033] This approach uses a chain structure of coupler multiplexing, demodulator detection, and host computer calculation to ensure real-time, high-precision transmission and processing of force signals.

[0034] Secondly, this application also provides an optical path connection system, characterized in that the optical path connection system includes: an intraocular micro-force sensing device, an optical fiber coupler, a fiber optic grating demodulator, and a host computer, as described in any possible implementation of the first aspect; in the optical path connection system, the output signal of each FBG in the FBG sensor array included in the intraocular micro-force sensing device is uniformly transferred to the optical fiber coupler via an optical fiber, the optical fiber coupler is connected to the fiber optic grating demodulator, the fiber optic grating demodulator is used to emit broadband light to the optical fiber coupler and detect the wavelength difference of each FBG, and transmit the wavelength difference data to the host computer via an Ethernet cable, the host computer is used to calculate the contact force between the surgical instrument and the eye tissue.

[0035] It is understood that the optical path connection system provided above includes an intraocular micro-force sensing device corresponding to any implementation of the first aspect. Therefore, its beneficial effects can be referred to the beneficial effects in the corresponding methods, and will not be repeated here. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the overall design of an intraocular micro-force sensing device provided in an embodiment of this application;

[0037] Figure 2 This is a schematic diagram of a potential layout of an FBG sensor array provided in an embodiment of this application;

[0038] Figure 3 This is a schematic diagram of a potential design scheme for an instrument cannula provided in an embodiment of this application;

[0039] Figure 4This is a schematic diagram illustrating the force application of an intraocular micro-force sensing device according to an embodiment of this application;

[0040] Figure 5 This is a schematic diagram of the optical path connection system corresponding to an intraocular micro-force sensing device provided in an embodiment of this application. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described below in conjunction with the accompanying drawings.

[0042] Please see Figure 1 , Figure 1 An intraocular micro-force sensing device is provided as an embodiment of this application. For example... Figure 1 As shown, the intraocular micro-force sensing device includes:

[0043] Fiber Bragg grating (FBG) sensor array (1) and instrument sleeve (2).

[0044] Each FBG in the FBG sensor array (1) is attached to the instrument sleeve (2). The instrument sleeve (2) is used to attach one or more flexible surgical instruments. The FBG sensor array (1) realizes in-situ measurement of the contact force between the instrument and the eye tissue by sensing the deformation of the instrument sleeve (2) due to contact with the eye tissue.

[0045] The number of FBG sensor arrays (1) is greater than or equal to 3, and the layout of the FBG sensor arrays (1) on the instrument cannula (2) satisfies the preset temperature interference separation condition, which includes: the sum of the displacements of all FBG sensors to the x-axis. =0, and the sum of the displacements of all FBG sensors to the y-axis. 0, n is the total number of FBG sensors in the FBG sensor array, and the center of the x-axis and y-axis is the geometric center of the instrument sleeve (2).

[0046] In some possible implementations, the instrument cannula (2) and the FBG sensor array (1) are bonded together with medical adhesive, such as 4013 adhesive or UV adhesive.

[0047] In some possible implementations, the instrument cannula (2) is used to attach one or more of the following instruments: surgical needle (3), surgical forceps (4), surgical hook (5), and light guide pen (6). Alternatively, other surgical instruments as required may be attached, which is not limited herein. When the end of an instrument (such as a surgical needle, forceps, hook, or light guide pen) comes into contact with the eye tissue, a contact force F is applied to the end of the instrument cannula (2). At this time, the instrument cannula (2), as a flexible cantilever beam structure, undergoes bending deformation due to the force on its end. Based on material mechanics, the strain at the location of the FBG is directly related to the contact force F. In some possible implementations, medical-grade sealant is applied to the connecting end face of the surgical instrument (e.g., light guide pen) and the cannula to form a continuous sealing interface; and / or, O-rings are added to the overlapping area of ​​the cannula and the surgical instrument to ensure sealing and strong adhesion.

[0048] In this application embodiment, the layout of the FBG sensor on the sleeve is not unique; several potential layout methods are as follows: Figure 2 As shown. Figure 2 As shown, the number of FBG sensors should be ≥3. They can be arranged uniformly or non-uniformly, but regardless of the method, the total displacement of all FBG sensors to the x-axis and y-axis should be zero.

[0049] For example, with Figure 2 Taking the top left subplot as an example, let's define the topmost FBG as 'FBG-1', the bottom left FBG as 'FBG-2', and the bottom right FBG as 'FBG-3'. Let the sleeve radius be R. Then the displacements of the three FBGs to the x-axis are R, ... 0.5R, and 0.5R, the sum of the three is zero. The distance from the three FBGs to the y-axis is 0. ,as well as The sum of the three is zero. The significance of this design is that if the instrument is subjected to forces in the x and y directions, the sum of the wavelength differences at the three FBGs should be zero. Therefore, if the sum of the measured wavelength differences of the FBGs is not zero, the non-zero part is due to temperature changes. This layout can be used to isolate the interference of temperature on the measurement results.

[0050] Based on the FBG sensor layout provided in this application (meeting the preset temperature interference separation conditions), the temperature drift of a single FBG can be expressed as the average wavelength change caused by temperature. Subsequently, by calculating the difference between the wavelength change of a single FBG and the average wavelength change, temperature interference can be completely eliminated, retaining only the wavelength change component caused by force. For example, for a one-dimensional force, the wavelength change of a single FBG can be calculated... The average wavelength change of the sum of wavelength differences measured by each FBG The difference This completely eliminates temperature interference. For two-dimensional or three-dimensional forces, the wavelength changes of a single FBG in various directions are calculated (e.g., The difference between the average temperature drift of all FBG sensors in the corresponding direction and the statistical average temperature drift of all FBG sensors in the corresponding direction is considered. Since the temperature field is isotropic in all directions under a uniform environment, ideally, the average wavelength change of all FBG sensors in each direction is the same (e.g., all are equal). ).

[0051] The intraocular micro-force sensing device provided in this application, on the one hand, solves the problem of large size in the field of intraocular micro-force sensing by combining a sub-millimeter miniaturized FBG sensor with a flexible sleeve, and achieves low invasiveness and high deformation transmission efficiency of the intraocular micro-force sensing device.

[0052] On the other hand, the number of FBG sensors is ≥3, and they adopt a layout that meets the preset temperature interference separation condition (the sum of the displacements of all FBGs to the x-axis and y-axis is 0). This eliminates the need for additional temperature sensors, directly utilizing the statistical characteristics of the sensor array, separation force, and temperature effects. This significantly simplifies the temperature compensation process, improves temperature interference issues, and enhances measurement real-time performance and reliability. For example, the wavelength change of a single FBG can be calculated subsequently. The average wavelength change of the sum of wavelength differences measured by each FBG The difference This will completely eliminate temperature interference.

[0053] On the other hand, this solution proposes a universal integrated framework of "FBG sensor + instrument cannula + surgical instruments", using the FBG sensor and cannula as basic components, which can be adapted to various instruments such as surgical needles (3), surgical forceps (4), surgical hooks (5), and light guide pens (6). This "modular + universal" design significantly reduces the development and maintenance costs of the multi-instrument force perception system of the surgical robot.

[0054] In some possible implementations, such as Figure 3 As shown in the left sub-figure, the instrument cannula (2) includes a single cannula scheme (7), wherein the FBG sensor array (1) is bonded to the outer wall of the instrument cannula (2).

[0055] As an example, if the instrument fitted to the instrument sheath (2) is not a surgical hook (5) or a light guide pen (6), the single-sheath design (7) may also have a through hole for the injection needle to carry the liquid or for installing a detachable component (e.g., the detachable component can be a surgical forceps core). For example, the injection needle (such as a micro-syringe needle) is inserted into the through hole of the single sheath, the syringe pushes the liquid, and the liquid is delivered into the eye through the injection needle and the through hole of the single sheath. If the instrument fitted to the instrument sheath (2) is a surgical hook (5) or a light guide pen (6), the single-sheath design (7) does not include a through hole design.

[0056] That is, when the instrument requires liquid transfer (such as liquid flow through an injection needle) or detachable component installation (such as the core of a surgical forceps), the through hole is retained to better assist the operation. When the instrument being fitted is a light guide pen (6), the light guide pen requires optical path integrity and has no liquid or component installation requirements, or when the instrument being fitted is a surgical hook (5), the surgical hook requires structural rigidity and smooth operation and has no internal hole function requirements. In this case, the through hole design is cancelled, the structure is optimized to meet the diverse needs.

[0057] In some other possible implementations, such as Figure 3 As shown in the right sub-figure, the instrument cannula (2) includes a double cannula scheme, which includes an outer cannula (8) and an inner cannula (9). The outer cannula (8) encloses the inner cannula (9), and the FBG sensor array (1) is attached to the outside of the inner cannula (9).

[0058] In this embodiment, when the instrument fitted by the instrument sleeve (2) is not a surgical hook (5) or a light guide pen (6), the inner sleeve (9) may have a through hole for the injection needle to flow fluid or for installing detachable parts. When the instrument fitted by the instrument sleeve (2) is a surgical hook (5) or a light guide pen (6), the inner sleeve (9) does not include a through hole design.

[0059] This dual-cannula design isolates the instrument surface from friction, protecting the FBG from mechanical damage. The spatial isolation provided by the outer cannula also reduces direct interference from the external environment (such as tissue fluid and blood) on the FBG, thereby improving the stability of force perception.

[0060] In application, the two schemes can be flexibly switched. When the required volume is as small as possible, the single-cannula scheme is used; when the required measurement is highly sensitive and accurate, the double-cannula scheme is used. This allows the instrument to adapt to complex surgical environments while ensuring high sensitivity of force measurement, thus meeting diverse needs.

[0061] In some possible implementations, the contact force calculation module connected to the intraocular microforce sensing device can calculate the wavelength change of a single FBG. The average wavelength change of the sum of wavelength differences measured by each FBG The difference This method eliminates temperature interference. Specifically, the contact force calculation module is used to calculate the contact force F between the surgical instrument and the eye tissue based on Formula 5.

[0062] Formula 5 is derived from the following deduction process:

[0063] like Figure 4 As shown, the contact force at the ends of the two bushings is defined as F, and the distance from the center of the FBG grid region (the solid black dot) to the end of the bushing is... Then the torque M at the center of the gate region = The relationship between the strain and the force F at the i-th FBG on the outer side of the casing is shown in Formula 1 below:

[0064] Strain at the i-th FBG The relationship between the force and the applied force F satisfies the following formula 1:

[0065]

[0066] Where E is the Young's modulus of the casing material. Let I be the distance from the i-th FBG to the neutral plane of the flexible cantilever of the casing, and let I be the moment of inertia of the casing section.

[0067] Wavelength change of the i-th FBG Caused by both deformation and temperature, it satisfies the following formula:

[0068]

[0069] in, This indicates the amount of change in the feedback wavelength caused by deformation. This indicates the amount of change in the feedback wavelength caused by temperature changes. Let i be the initial feedback wavelength of the i-th FBG. The elastic coefficient is 1. The coefficient of thermal expansion is... Thermo-optic coefficient, This refers to the change in temperature.

[0070] Combining Formula 1 and Formula 2, we obtain the following Formula 3:

[0071]

[0072] Because the layout of the FBG sensor array (1) satisfies If the average wavelength change caused by temperature is only related to temperature, then the following formula 4 holds:

[0073]

[0074] Combining formulas 3 and 4, we obtain formula 5:

[0075]

[0076] In this embodiment, regardless of whether the force measured by the FBG is one-dimensional, two-dimensional, or three-dimensional, the number and distribution of the FBG sensors must meet the following requirements. , All are 0. In some possible implementations, for three-dimensional force scenes, if conditions permit, the distribution of the FBG sensors can also satisfy... It equals 0.

[0077] In two-dimensional or three-dimensional force scenarios, the deformation wavelength change of a single FBG is determined by calculating the difference between the wavelength change of a single FBG in each direction and the statistical average of the temperature drift of all FBG sensors in the corresponding direction.

[0078] Since the temperature field is isotropic in all directions under uniform conditions, ideally, the average wavelength change of the FBG sensor is the same in all directions. Therefore, the average wavelength change can be obtained by calculating the average of the wavelength changes in one direction (or two directions) (allowing for some error). For example, in a three-dimensional force scenario, the average wavelength change can be obtained by calculating the average of the wavelength changes in the x-direction (or the x-direction and y-direction).

[0079] In two-dimensional or three-dimensional force scenarios, the force vector With wavelength change vector A linear relationship exists. It can be represented in vector form as shown in Formula 6 below, where, These are matrix coefficients, designed by comprehensively considering factors such as material properties, grating structure, and working environment.

[0080]

[0081] For example, formulas 1 to 5 above can correspond to two-dimensional or three-dimensional forces. The derivation process of the force in a certain direction.

[0082] In some possible implementations, the aforementioned contact force calculation module can also be used to calculate the maximum force error based on error requirements. Determine the critical wavelength change using the following formula 7. :

[0083]

[0084] like If the measurement accuracy of the demodulator is greater than that of the demodulator (the demodulator's measurement accuracy is designed based on specific requirements, such as 1pm, 5pm, or 10pm), then the contact force calculation module determines that the maximum force error of the FBG sensor is less than or equal to the required accuracy. This meets the accuracy requirements.

[0085] like If the measurement accuracy is less than or equal to that of the demodulator, the contact force calculation module will adjust accordingly. , E, I or The value of increases So that The measurement accuracy is greater than that of the demodulator, ensuring that the measurement is feasible.

[0086] Generally, traditional force sensing systems typically determine whether the accuracy meets the standard by using error statistics after measurement.

[0087] However, this scheme uses Formula 7 to account for the theoretical error. This is directly related to the actual capabilities of the demodulator, avoiding the contradiction of high theoretical accuracy that cannot be achieved by hardware, and enabling error pre-assessment before measurement to avoid invalid data acquisition due to unreasonable parameters, thereby improving measurement efficiency. Furthermore, by adjusting... , E, I or It can increase dS in a targeted manner, supports dynamic parameter optimization, and improves the system's adaptability to different application scenarios.

[0088] In some possible implementations, the intraocular microforce sensing device provided in this application is applied to an optical path connection system. In the optical path connection system, the output signal of each FBG in the FBG sensor array (1) is uniformly transferred to the fiber coupler (10) through an optical fiber. The fiber coupler (10) is connected to the fiber optic demodulator (11). The fiber optic demodulator (11) is used to emit broadband light to the fiber coupler (10) and detect the wavelength difference of each FBG, and transmit the wavelength difference data to the host computer (12) through an Ethernet cable. The host computer (12) is used to calculate the contact force between the surgical instrument and the eye tissue.

[0089] It should be noted that the contact force calculation module can be a module in the host computer (12), or the contact force calculation module is the host computer (12).

[0090] This approach uses a chain structure of coupler multiplexing, demodulator detection, and host computer calculation to ensure real-time, high-precision transmission and processing of force signals.

[0091] like Figure 5As shown, this application embodiment also provides an optical path connection system, which includes: any of the intraocular micro-force sensing devices described above, an optical fiber coupler (10), a fiber optic demodulator (11), and a host computer (12); in the optical path connection system, the output signal of each FBG in the FBG sensor array (1) included in the intraocular micro-force sensing device is uniformly transferred to the optical fiber coupler (10) through an optical fiber, the optical fiber coupler (10) is connected to the fiber optic demodulator (11), the fiber optic demodulator (11) is used to emit broadband light to the optical fiber coupler (10) and detect the wavelength difference of each FBG, and transmit the wavelength difference data to the host computer (12) through an Ethernet cable, the host computer (12) is used to calculate the contact force between the surgical instrument and the eye tissue.

[0092] It is understood that the optical path connection system provided above includes the intraocular micro-force sensing device provided in this application. Therefore, the beneficial effects it can achieve can be referred to the beneficial effects in the corresponding intraocular micro-force sensing device, which will not be described in detail here.

[0093] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it includes the processes of the embodiments of the above methods.

[0094] The term "at least one" in this application refers to one or more items. "More than one item" means two or more items. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship. Furthermore, it should be understood that although the terms "first," "second," etc., may be used to describe objects in this application, these objects should not be limited to these terms. These terms are only used to distinguish the objects from each other.

[0095] The terms “including” and “having” mentioned above, and any variations thereof, are intended to cover non-exclusive inclusion.

[0096] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An intraocular micro-force sensing device, characterized in that, include: Fiber Bragg grating (FBG) sensor array (1) and instrument sleeve (2); Each FBG in the FBG sensor array (1) is attached to the instrument sleeve (2), which is used to fit a flexible surgical instrument. The FBG sensor array (1) realizes in-situ measurement of the contact force between the surgical instrument and the eye tissue by sensing the deformation of the instrument sleeve (2) due to contact with the eye tissue. Wherein, the number of FBGs in the FBG sensor array (1) is greater than or equal to 3, and the layout of the FBG sensor array (1) on the instrument cannula (2) satisfies a preset temperature interference separation condition, the preset temperature interference separation condition including: the sum of the displacements of all FBG sensors to the x-axis =0, and the sum of the displacements of all FBG sensors to the y-axis. The value is 0, where n is the total number of FBG sensors, the center of the x-axis and the y-axis is the geometric center of the instrument cannula (2), and the n FBGs in the FBG sensor array (1) are allowed to be arranged uniformly or non-uniformly. The instrument sleeve (2) is used to attach any one or more of the following instruments: surgical needle (3), surgical forceps (4), surgical hook (5), and light guide pen (6). The intraocular micro-force sensing device is connected to the contact force calculation module. The contact force calculation module is used to eliminate the influence of temperature wavelength change based on the difference between the total wavelength change and the average wavelength change of the first FBG, and obtain the deformation wavelength change corresponding to the first FBG. The contact force F between the surgical instrument and the eye tissue is calculated based on the deformation wavelength change corresponding to the first FBG. The average wavelength change is the average value of the sum of the wavelength differences of all FBGs. The first FBG is any one of the FBGs in the FBG sensor array. The contact force calculation module is specifically used to calculate the contact force F between the surgical instrument and the eye tissue based on Formula 5, which is derived from the following deduction process: Strain at the i-th FBG The relationship between the contact force F and the contact force F satisfies the following formula 1: ； Wherein, F represents the contact force at the end of the instrument cannula (2), M is the distance from the center of the FBG grid region to the end of the instrument sleeve (2), M is the torque at the center of the FBG grid region when the end of the instrument sleeve (2) is subjected to contact force F, and E is the Young's modulus of the sleeve material. Let I be the distance from the i-th FBG to the neutral plane of the flexible cantilever of the casing, and let I be the moment of inertia of the casing section. Wavelength change of the i-th FBG Caused by both deformation and temperature, it satisfies the following formula: ； in, This indicates the amount of change in the feedback wavelength caused by deformation. This indicates the amount of change in the feedback wavelength caused by temperature changes. Let i be the initial feedback wavelength of the i-th FBG. The elastic coefficient is 1. The coefficient of thermal expansion is... Thermo-optic coefficient, This refers to the change in temperature. Combining Formula 1 and Formula 2, we obtain the following Formula 3: ； Because the layout of the FBG sensor array (1) satisfies If the average wavelength change caused by temperature is only related to temperature, then the following formula 4 holds: ； Combining formulas 3 and 4, we obtain formula 5: 。 2. The intraocular micro-force sensing device as described in claim 1, characterized in that, The instrument cannula (2) includes a single cannula scheme (7), and the FBG sensor array (1) is bonded to the outer wall of the instrument cannula (2); If the instrument fitted to the instrument sleeve (2) is not a surgical hook (5) or a light guide pen (6), the single sleeve solution (7) also has a through hole for the injection needle to flow liquid or for installing detachable parts. When the instrument fitted to the instrument sleeve (2) is a surgical hook (5) or a light guide pen (6), the single sleeve scheme (7) does not include a through hole design.

3. The intraocular micro-force sensing device as described in claim 1, characterized in that, The instrument cannula (2) includes a double cannula scheme, which includes an outer cannula (8) and an inner cannula (9). The outer cannula (8) encloses the inner cannula (9), and the FBG sensor array (1) is attached to the outside of the inner cannula (9).

4. The intraocular micro-force sensing device as described in claim 3, characterized in that, If the instrument fitted to the instrument sleeve (2) is not a surgical hook (5) or a light guide pen (6), the inner sleeve (9) also has a through hole for the injection needle to flow liquid or for installing detachable parts. When the instrument fitted to the instrument sleeve (2) is a surgical hook (5) or a light guide pen (6), the inner sleeve (9) does not contain a through hole design.

5. The intraocular micro-force sensing device as described in claim 1, characterized in that, The contact force calculation module is also used to determine the maximum force error based on the error requirement. Determine the critical wavelength change using the following formula. : like If the measurement accuracy is greater than that of the demodulator, then the contact force calculation module determines that the maximum force error of the FBG sensor is less than or equal to the measurement accuracy of the demodulator. This meets the accuracy requirements; like If the measurement accuracy is less than or equal to that of the demodulator, the contact force calculation module can adjust... , E, I or The value of increases So that The measurement accuracy is greater than that of the demodulator, ensuring that the measurement is feasible.

6. The intraocular micro-force sensing device as described in claim 1, 4, or 5, characterized in that, Used in optical path connection systems, In the optical path connection system, the output signal of each FBG in the FBG sensor array (1) is uniformly transferred to the fiber coupler (10) through the optical fiber, and the fiber coupler (10) is connected to the fiber optic demodulator (11). The fiber grating demodulator (11) is used to emit broadband light to the fiber coupler (10) and detect the wavelength difference of each FBG, and transmit the wavelength difference data to the host computer (12) via Ethernet cable. The host computer (12) is used to calculate the contact force between the surgical instruments and the eye tissue.

7. An optical path connection system, characterized in that, The optical path connection system includes: an intraocular micro-force sensing device as described in any one of claims 1 to 6, an optical fiber coupler (10), a fiber optic demodulator (11), and a host computer (12). In the optical path connection system, the output signal of each FBG in the FBG sensor array (1) of the intraocular micro-force sensing device is uniformly transferred to the fiber coupler (10) through the optical fiber. The fiber coupler (10) is connected to the fiber optic demodulator (11). The fiber optic demodulator (11) is used to emit broadband light to the fiber coupler (10) and detect the wavelength difference of each FBG, and transmit the wavelength difference data to the host computer (12) through the Ethernet cable. The host computer (12) is used to calculate the contact force between the surgical instrument and the eye tissue.

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