Fiber bragg grating sensor for multi-dimensional force measurement and minimally invasive cardiac surgery tool head

Abstract

The invention provides a fiber bragg grating sensor for multi-dimensional force measurement and a minimally invasive cardiac surgery tool head, and belongs to the technical field of fiber bragg grating sensing, and the fiber bragg grating sensor comprises a front integrated machined part which is cylindrical and is welded with a force sensitive element; the force sensitive element is of a cylindrical dumbbell-shaped hollow structure; the rear integrated processing part is cylindrical and is welded with the force sensitive element; and the four optical fibers are respectively engraved with customized Bragg gratings. The force sensing element can change the force measuring range, the force measuring precision and the force measuring sensitivity through carving optimization design, and can meet the force sensing requirements of wider minimally invasive surgical instruments.

Description

Technical Field

[0001] The present invention relates to the technical field of fiber grating sensing, and in particular to a fiber grating sensor for multi-dimensional force measurement and a minimally invasive cardiac surgery tool head. Background Art

[0002] Minimally invasive surgery has become a key area of development in modern cardiac surgery, significantly reducing surgical side effects, lowering complication rates, improving surgical safety, and improving outcomes compared to previous procedures. However, it also faces the serious challenge of lacking tactile perception during surgery.

[0003] Fiber Bragg grating (FBG) sensing technology can be used for force measurement and is well-suited for miniaturization. It not only addresses the integration challenges of force sensors within the confined spaces of minimally invasive instruments, but also uses light as a physical information carrier, offering robust immunity to electromagnetic interference in electromagnetic environments and enabling its use in surgical environments guided by MRI images. Furthermore, optical fiber is made of silica, which is heat-resistant and corrosion-resistant, making it easy to sterilize.

[0004] Minimally invasive cardiac surgery tool heads are mounted at the end of slender cylindrical surgical tools or serpentine arms to perform operations such as vascular clamping, soft tissue mobilization, and shearing. When a doctor or robot performs a surgical procedure, the lack of force sensing at the end of the tool head can easily cause accidental damage to blood vessels and soft tissue, posing a significant risk to the procedure. Summary of the Invention

[0005] The object of the present invention is to provide a fiber grating sensor for multi-dimensional force measurement and a minimally invasive cardiac surgery tool head to solve at least one technical problem existing in the above-mentioned background technology.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] In one aspect, the present invention provides a fiber Bragg grating sensor for multi-dimensional force measurement, comprising:

[0008] The front integrated processing part is cylindrical and welded to the force-sensitive element;

[0009] The force-sensitive element is a cylindrical dumbbell-shaped hollow structure;

[0010] The post-integrated processed part is cylindrical and welded to the force-sensitive element;

[0011] Four optical fibers, each engraved with a customized Bragg grating.

[0012] As a further limitation of the first aspect of the present invention, four customized Bragg gratings are used as sensing elements to measure the axial force and radial force exerted on the distal end of the surgical tool head, so that the optical fiber force sensor has higher measurement accuracy and stability.

[0013] As a further limitation of the first aspect of the present invention, the four optical fibers engraved with the Bragg gratings are fixed on the front integrated processing component and the back integrated processing component.

[0014] As a further limitation of the first aspect of the present invention, the four optical fibers are parallel to each other and to the central axis of the force-sensitive element, and the four Bragg gratings are placed in the middle of the force-sensitive element.

[0015] As a further limitation of the first aspect of the present invention, the force-sensitive element is a hollow cylindrical tube, the tube body of which is made of nickel-titanium alloy material and is allowed to undergo elastic deformation when subjected to force.

[0016] As a further limitation of the first aspect of the present invention, the force-sensitive element tube body is hollowed out with dumbbell-shaped slots, and the dumbbell-shaped slots have three layers, each layer has four slots, which are evenly distributed at 90 degrees on the circumference, and the slots in each layer are staggered 45 degrees from each other.

[0017] As a further limitation of the first aspect of the present invention, four circular holes are provided on the equal diameter circumferences of the right side of the front integrated processing piece and the left side of the rear integrated processing piece, and the four optical fibers can pass through and be fixed on the circular holes respectively.

[0018] As a further limitation of the first aspect of the present invention, a through hole is provided in the center of the right side of the front integrated processing piece and the left side of the rear integrated processing piece to allow the wire drawing driving the minimally invasive surgical tool head to pass through.

[0019] As a further limitation of the first aspect of the present invention, the right side of the front integrated processing piece and the left side of the rear integrated processing piece are respectively inserted into the left and right ends of the force sensitive element and are welded at high temperature.

[0020] In a second aspect, the present invention provides a minimally invasive cardiac surgical tool head, wherein the minimally invasive surgical tool head comprises the fiber Bragg grating sensor for multi-dimensional force measurement as described in the first aspect.

[0021] The beneficial effects of the present invention are as follows: the force-sensitive element of the sensor is designed through engraving optimization, which can change the force measurement range, force measurement accuracy and force measurement sensitivity, and can be suitable for a wider range of minimally invasive surgical instrument force sensing requirements.

[0022] Additional aspects and advantages of the present invention will be set forth in part in the following description, will become apparent from the following description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 Schematic diagram of the structure of the fiber Bragg grating force sensor according to an embodiment of the present invention.

[0025] Figure 2 Pictured Figure 1 The front integrated processing structure at the far end of the force sensor.

[0026] Figure 3 Pictured Figure 1 The structure of the force sensitive element in the middle of the force sensor.

[0027] Figure 4 Pictured Figure 1 The structure of the post-integration processing part located near the force sensor.

[0028] Figure 5 This is a structural diagram of a minimally invasive cardiac surgery tool head according to an embodiment of the present invention.

[0029] Among them: 1-front integrated processing part; 2-force sensitive element; 3-rear integrated processing part; 4-first Bragg grating; 5-second Bragg grating; 6-third Bragg grating; 7-fourth Bragg grating; 8-center through hole on the right side of the front integrated processing part; 9-optical fiber fixing circular hole on the right side of the front integrated processing part; 10-fan-shaped hole on the right side of the front integrated processing part; 11-multi-layer dumbbell-shaped hollow structure of the force sensitive element; 12-center through hole on the left side of the rear integrated processing part; 13-optical fiber fixing circular hole on the left side of the rear integrated processing part; 14-fan-shaped hole on the left side of the rear integrated processing part. DETAILED DESCRIPTION

[0030] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention and are not to be construed as limiting the present invention.

[0031] Those skilled in the art will understand that unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which this invention belongs.

[0032] It should also be understood that terms, such as those defined in commonly used dictionaries, should be understood to have a meaning consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless as defined herein.

[0033] Those skilled in the art will appreciate that, unless otherwise stated, the singular forms "a," "an," "said," and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present invention refers to the presence of the stated features, integers, steps, operations, elements, and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, and / or groups thereof.

[0034] In the description of this specification, reference to the terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and integrate different embodiments or examples described in this specification, as well as features of different embodiments or examples, unless otherwise inconsistent.

[0035] In the description of this specification, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0036] In the description of this specification, the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing the present technology and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, they should not be understood as limiting the present technology.

[0037] Unless otherwise specified or limited, the terms "installed," "connected," "connected," and "disposed" should be understood broadly. For example, they may refer to fixed connection or disposition, detachable connection or disposition, or integral connection or disposition. Those skilled in the art will understand the specific meanings of these terms in this technology based on specific circumstances.

[0038] To facilitate understanding of the present invention, the present invention is further explained below with reference to specific embodiments in conjunction with the accompanying drawings. However, the specific embodiments do not constitute a limitation on the embodiments of the present invention.

[0039] Those skilled in the art should understand that the drawings are merely schematic diagrams of embodiments, and the components in the drawings are not necessarily necessary for implementing the present invention.

[0040] In this embodiment, a fiber grating sensor for sensing the force acting on the distal end of a cardiac surgical tool head is provided. The fiber grating sensor can measure the axial and radial forces acting on the distal end of the cardiac surgical tool head.

[0041] The fiber Bragg grating sensor of this embodiment is as follows Figure 1 As shown, it includes a front integrated processing part 1, a rear integrated processing part 3, a force sensitive element 2, and four optical fibers engraved with a first Bragg grating 4, a second Bragg grating 5, a third Bragg grating 6, and a fourth Bragg grating 7 for realizing axial and radial force measurement.

[0042] In the above-mentioned fiber Bragg grating sensor, the front integrated processing part 1, the rear integrated processing part 3, and the force-sensitive element 2 are made of medical nickel-titanium alloy material with superelastic properties.

[0043] In the above-mentioned fiber Bragg grating sensor, the force applied to the end of the tool head during surgery is transmitted to the force sensitive element 3 connected to the right side of the front integrated processing piece 1 through the left side of the front integrated processing piece 1 .

[0044] In the above-mentioned fiber Bragg grating sensor, the front integrated processing part 1 is an integral cylindrical part, such as Figure 2 As shown, the left side is a through hole for mounting with the surgical tool head, the right side is processed with four fan-shaped holes 10, the center is reserved with a through hole 8 for passing the wire drawing that drives the surgical tool head, and a circular hole 9 for fixing the distal ends of four optical fibers.

[0045] In the above-mentioned fiber Bragg grating sensor, Figure 1 As shown, the central wavelength changes of the four Bragg gratings 4, 5, 6, and 7 due to the force applied can be used to calculate the axial and radial forces acting on the sensor. The use of four Bragg gratings makes the fiber Bragg grating sensor have higher measurement accuracy and stability.

[0046] In the above-mentioned fiber Bragg grating sensor, the force sensitive element 2 is a hollow cylindrical tube, and its tube body is hollowed out and optimized. Figure 3 As shown, the hollow structure 11 is a dumbbell-shaped multi-layer continuous beam stack, which meets the performance requirements of force measurement range, force measurement accuracy, force measurement sensitivity, and axial and radial force decoupling in minimally invasive cardiac surgery.

[0047] In the above-mentioned fiber Bragg grating sensor, the post-integrated processing part 3 is an integral component, such as Figure 4 As shown, the left side is connected to the force-sensitive element 2, four fan-shaped holes 14 are processed on the left side, and a through hole 12 for driving the drawing wire of the surgical tool head and a circular hole 13 for fixing the proximal ends of four optical fibers are reserved in the center.

[0048] In the above-mentioned fiber Bragg grating sensor, the circular holes 9 and 13 for fixing four optical fibers on the front integrated processing component 1 and the rear integrated processing component 3 are evenly distributed at 90 degrees on the circumference of the equal diameter.

[0049] In the above-mentioned fiber Bragg grating sensor, Bragg gratings 4, 5, 6, and 7 are suspended and packaged in the lumen of the force-sensitive element 2. The axial and radial deformations of the force-sensitive element 2 are transmitted to the four fiber Bragg gratings, generating strain and changing their central wavelengths.

[0050] like Figure 5 As shown, the fiber Bragg grating sensor for measuring multidimensional force in this embodiment includes an integrated minimally invasive cardiac surgical tool head. The sensor's force-sensitive element has been optimized through engraving to adjust the force measurement range, accuracy, and sensitivity, adapting to a wider range of minimally invasive surgical instrument force sensing requirements.

[0051] The fiber Bragg grating (FBG) sensor described in this embodiment is connected front-to-back to a cardiac surgical tool head and a serpentine arm. The minimally invasive cardiac surgical tool head is sealed to the front integrated component of the fiber Bragg grating sensor. The serpentine arm controls the position and opening and closing of the minimally invasive surgical tool head and is fixed to the rear integrated component of the fiber Bragg grating sensor. In one specific embodiment, the fiber Bragg grating sensor and serpentine arm are sealed together, thereby preventing bodily fluids from entering the lumen of the fiber Bragg grating sensor and serpentine arm during surgery.

[0052] In a specific embodiment, the front integrated processing part 1, the rear integrated processing part 3 and the force sensitive element 2 are medical nickel-titanium round tubes with an outer diameter of 6 mm. The protruding cylinder on the right side of the front integrated processing part 1 is adapted to the left cavity of the force sensitive element 2, and the protruding cylinder on the left side of the rear integrated processing part 2 is adapted to the right cavity of the force sensitive element 2.

[0053] In a specific embodiment, the optical fiber fixing circular hole 9 on the right side of the front integrated processing part 1 and the optical fiber fixing circular hole 13 on the left side of the rear integrated processing part 3 are coaxially positioned, and the front integrated processing part 1 and the rear integrated processing part 3 are installed and fixed to the force sensitive element by high-temperature welding.

[0054] In a specific embodiment, the four optical fibers are parallel to the axis of the force-sensitive element 2 , and the customized Bragg gratings 4 , 5 , 6 , 7 on the four optical fibers are evenly arranged on the circumference and are located in the middle of the force-sensitive element 2 .

[0055] In a specific embodiment, the four optical fibers pass through the inner cavity of the serpentine arm and enter the fiber optic Bragg grating sensor, one end is fixed to the front integrated processing part 1, and the middle is fixed to the rear integrated processing part 3, and the Bragg gratings 4, 5, 6, and 7 are placed in the middle 3 between the front integrated processing part 1 and the rear integrated processing part. The other end of the optical fiber is connected to the grating demodulator outside the serpentine arm through an extended optical fiber line.

[0056] In a specific embodiment, the force sensitive element 2 is a hollow circular tube, and three layers of dumbbell-shaped slots are processed on the tube body of the force sensitive element 2 using laser processing technology. Each layer has four slots, which are evenly distributed at 90 degrees on the circumference. The slots in each layer are staggered by 45 degrees, forming a hollow structure on the force sensitive element 2.

[0057] In a specific embodiment, it should also be understood that the packaging process of the fiber Bragg grating sensor of the present invention is key to ensuring its performance. The four optical fibers, respectively fixed to the front integrated processing component 1 and the rear integrated processing component 2, must be as parallel as possible to the central axis of the force-sensitive element 2; the prestress applied to the Bragg grating on each optical fiber must be as consistent as possible; the fiber fixing adhesive material used must minimize deformation transmission losses of the force-sensitive element 2; and the impact of ambient temperature changes must be eliminated as much as possible during the packaging process. In addition, the use of four Bragg gratings (FBGs) ensures that the fiber Bragg grating sensor has higher measurement accuracy, and even in the event of failure of one of the FBGs, highly accurate multi-dimensional force measurements can still be achieved.

[0058] In a specific embodiment, it should be understood that the resolution of the grating interrogator and the force-wavelength relationship model of the fiber Bragg grating sensor will affect the measurement accuracy and sensitivity of the fiber Bragg grating sensor of the present invention. Specifically, using a higher-resolution grating interrogator and a more accurate force-wavelength deep learning relationship model can improve the measurement accuracy and sensitivity of the fiber Bragg grating sensor.

[0059] In summary, the fiber Bragg grating force sensor described in the embodiment of the present invention is used to measure the axial and radial forces on the end of a cardiac minimally invasive surgical tool. The fiber Bragg grating force sensor is placed between the cardiac surgical tool head and the serpentine arm, and includes four optical fibers, a force-sensitive element, a front integrated processing piece, and a rear integrated processing piece. The optical fiber is engraved with a Bragg grating, passes through the inner cavity of the serpentine arm, and is fixed to the front integrated processing piece and the rear integrated processing piece. The force on the cardiac surgical tool head is modulated by the force-sensitive element and transmitted to the optical fiber, causing the center wavelength of the Bragg grating to drift. The drift signal is input into the grating demodulator through the extended optical fiber. The center wavelength of the Bragg grating measured by the grating demodulator is used to establish a relationship model between wavelength drift and force, and calculate the force on the end of the cardiac surgical tool head. By varying the design of the force-sensitive element, fiber Bragg grating force sensors with different measurement ranges, accuracy, and sensitivity can be obtained, which can meet a wider range of multi-dimensional force perception requirements at the end of minimally invasive surgical instruments.

[0060] Although the above describes the specific embodiments of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solutions disclosed in the present invention without the need for creative work should be included in the scope of protection of the present invention.

Claims

1. A fiber Bragg grating sensor for multi-dimensional force measurement, characterized in that: include: The front integrated processing part is cylindrical and welded to the force-sensitive element; The force-sensitive element is a cylindrical dumbbell-shaped hollow structure; The post-integrated processed part is cylindrical and welded to the force-sensitive element; Four optical fibers, each engraved with a customized Bragg grating.

2. The fiber Bragg grating sensor for multi-dimensional force measurement according to claim 1, characterized in that: Four customized Bragg gratings are used as sensing elements to measure the axial force and radial force exerted on the distal end of the surgical tool head, so that the optical fiber force sensor has higher measurement accuracy and stability.

3. The fiber Bragg grating sensor for multi-dimensional force measurement according to claim 2, characterized in that: The four optical fibers engraved with the Bragg gratings are fixed on the front integrated processing component and the rear integrated processing component.

4. The fiber Bragg grating sensor for multi-dimensional force measurement according to claim 3, characterized in that: The four optical fibers are parallel to each other and to the central axis of the force-sensitive element, and the four Bragg gratings are placed in the middle of the force-sensitive element.

5. The fiber Bragg grating sensor for multi-dimensional force measurement according to claim 4, characterized in that: The force-sensitive element is a hollow cylindrical tube, the tube body of which is made of nickel-titanium alloy material and is allowed to undergo elastic deformation when subjected to force.

6. The fiber Bragg grating sensor for multi-dimensional force measurement according to claim 5, characterized in that: The force-sensitive element tube body is hollowed out with dumbbell-shaped slots, which have three layers, each layer has four slots, which are evenly distributed at 90 degrees on the circumference, and the slots in each layer are staggered at 45 degrees.

7. The fiber Bragg grating sensor for multi-dimensional force measurement according to claim 6, characterized in that: Four circular holes are provided on the equal-diameter circumferences of the right side of the front integrated processing piece and the left side of the rear integrated processing piece, and the four optical fibers can pass through and be fixed on the circular holes respectively.

8. The fiber Bragg grating sensor for multi-dimensional force measurement according to claim 7, characterized in that: A through hole is provided in the center of the right side of the front integrated processing piece and the left side of the rear integrated processing piece, allowing the wire drawing driving the minimally invasive surgery tool head to pass through.

9. The fiber Bragg grating sensor for multi-dimensional force measurement according to claim 8, characterized in that: The right side of the front integrated processing piece and the left side of the rear integrated processing piece are respectively inserted into the left and right ends of the force sensitive element and are welded at high temperature.

10. A minimally invasive cardiac surgical tool head, characterized in that: The minimally invasive surgical tool head includes the multi-dimensional force measurement fiber Bragg grating sensor according to any one of claims 1 to 9.

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