Bragg sensor and detection method for detecting narrowing of curved blood vessels in space

Abstract

The present invention provides a Bragg sensor and a detection method for detecting the stenosis of curved blood vessels in space, which are used for sensing and measuring curved blood vessels in space and closed microchannels through FBG intervention. The present invention forms distributed measurement points for sensing and measuring curved blood vessels in space and closed microchannels. The central catheter of the present invention forms a non-contact area with the FBG grating measurement points of the sensor, so that the deformation of the grating area is not affected by the adhesion of the contact area. A flexible and deformable tendon is naturally formed, which bends, stretches, or twists with the overall sensor to form a free expansion and contraction state, so that the sensor can form spatial bending and twisting. The sensor can measure the stenosis of blood vessels in space, and multiple grating points are arranged in a 120° distribution in a plane. When the sensor can form spatial bending and twisting, the grating points become a spatial layout. When the sensor moves in the blood vessel, it can cover the entire inner wall of the blood vessel and detect all stenotic areas.

Description

Technical Field

[0001] The present invention relates to the field of medical detection, and in particular to a Bragg sensor for detecting the stenosis of a curved blood vessel in space and a detection method. Background Art

[0002] FBG has good magnetic compatibility, small size, and flexible changeability. The present invention combines the advantages of magnetic resonance imaging (MRI) and FBG sensing, and uses the magnetic compatibility, flexible and small size of optical fiber sensing to work together in a magnetic resonance environment, so that the medical intervention robot can accurately locate in a closed blood vessel cavity.

[0003] Interventional treatment of curved vessels in space is a difficult problem internationally due to the tortuous paths and complex deformations associated with medical devices such as catheters and endoscopes. Shape is usually obtained by integrating strain measurements at different angles along the optical fiber. The accuracy of the generated shape depends on the sensor's resolution of the deformation distribution. In other words, the more information obtained along the arc length of the sensor, the better the deformation resolution and the more accurate the constructed 3D shape.

[0004] There are several technologies for fiber optic strain sensing. The two most common ones rely on fiber Bragg gratings (FBGs) and Rayleigh scattering. FBG-based strain sensing relies on reflected wavelengths from the emission spectrum. The reflected light depends on the periodicity of the grating, which is a function of the internal strain. The technology typically provides a discrete distribution of FBGs, allowing bending strain measurements to be made at a large number of discrete locations. In general, shape detection of slender curved structures is more challenging because higher deflections and torsions can occur. Therefore, error analysis from measuring wavelength to sensing shape becomes more important. In addition, the shape accuracy must be very accurate because errors accumulate along the optical fiber. The present invention obtains spatial shape information of the blood vessel by forming distributed measurement points through three multi-core optical fibers. Summary of the invention

[0005] In view of the defects in the prior art, the object of the present invention is to provide a Bragg sensor and a detection method for detecting the stenosis of a curved blood vessel in space.

[0006] A Bragg sensor for detecting stenosis of a curved blood vessel in space provided by the present invention comprises a first elastic central catheter, a second elastic central catheter, an optical fiber sensor and an interventional instrument, wherein:

[0007] A plurality of optical fiber sensors are provided, and the plurality of optical fiber sensors are bonded to the outer surface of the first elastic central conduit at equal intervals along the circumference of the first elastic central conduit;

[0008] The interventional device is disposed inside the first elastic central catheter;

[0009] The second elastic central catheter is sleeved on the outer sides of the plurality of optical fiber sensors.

[0010] Preferably, the optical fiber sensor comprises a FBG sensor and a tight sleeve arranged outside the FBG sensor, and the tight sleeve is bonded to the outer surface of the first elastic central conduit.

[0011] Preferably, a plurality of FBG sensors are provided on the optical fiber sensor, and the plurality of FBG sensors are distributed at equal intervals.

[0012] Preferably, an optical fiber coating layer is provided on the outer periphery of the FBG sensor, and the coating layer is tightly wrapped by a tight sleeve.

[0013] Preferably, one end of the optical fiber sensor is provided with a pigtail length, and the other end is fused with an FC / APC connector.

[0014] Preferably, a spacer is provided between adjacent FBG sensors, and the optical fiber sensor is bonded to the first elastic central conduit via the spacer.

[0015] Preferably, the first elastic central conduit and the second elastic central conduit are central conduits made of non-magnetic materials.

[0016] Preferably, three optical fiber sensors are provided, and six FBG sensors are evenly distributed on each optical fiber sensor.

[0017] Preferably, the FBG sensor is not in contact with the first elastic central catheter.

[0018] Preferably, the optical fiber coating layer is coated with acrylate.

[0019] According to the present invention, a detection method based on the Bragg sensor for detecting the stenosis of a curved blood vessel in space, comprising the following steps:

[0020] Assembling steps: arranging a plurality of optical fiber sensors, each optical fiber sensor comprising a plurality of FBG sensors, and a spacing area being arranged between adjacent FBG sensors;

[0021] Bonding step: a plurality of optical fiber sensors are distributed at equal intervals along the radial direction of the first elastic central conduit, and the optical fiber sensors are bonded to the outer surface of the first elastic central conduit through the spacing area;

[0022] Shape information acquisition step: acquiring the blood vessel spatial shape information based on the test results of multiple FBG sensors.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The present invention obtains the spatial shape information of blood vessels by setting three multi-core optical fibers to form distributed measurement points.

[0025] 2. The present invention bonds the optical fiber sensor to the first elastic central catheter through the spacer area, so that the FBG sensor is not affected by the bonding point and naturally forms a flexible and deformable tendon. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0027] Figure 1 Schematic diagram of the integration of three fiber 18 grating sensors and a blood vessel model.

[0028] Figure 2 Schematic diagram of the optical fiber sensor in the FBG grating area.

[0029] Figure 3 Schematic diagram of the Bragg sensor structure for detecting narrowing of curved blood vessels in space.

[0030] Figure 4 Schematic diagram of the cross section of a Bragg sensor for detecting stenosis in a spatially curved blood vessel.

[0031] Figure 5 Explosion diagram of a Bragg sensor for detecting narrowing of curved blood vessels in space.

[0032] The figure shows:

[0033] Interventional Devices1

[0034] First elastic central catheter 2

[0035] Fiber Optic Sensor 3

[0036] FBG sensor 301

[0037] Coating 302

[0038] Tight casing 303

[0039] Second elastic central catheter 4 DETAILED DESCRIPTION

[0040] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0041] like Figures 1 to 5As shown, a technique and method for sensing and measuring curved blood vessels and closed microchannels in space through FBG intervention is provided according to the present invention. In vascular interventional treatment, navigation of curved blood vessels is an internationally difficult problem due to the tortuous paths and complex deformations associated with medical devices such as catheters and endoscopes. The shape is usually obtained by integrating strain measurements at different angles along optical fiber multi-point sensors. The present invention senses and measures curved blood vessels and closed microchannels in space by forming distributed measurement points through three multi-core optical fibers.

[0042] The Bragg sensor for detecting spatially curved blood vessel stenosis of the present invention comprises three optical fibers (Fiber), and the optical fibers comprise 18 grating FBG sensor segments spatially distributed along the longitudinal extension of the blood vessel. The first elastic central catheter, namely the catheter TubeⅠ, guides the intervention device (needle) and is configured to be inserted into the artery (blood vessel model MX), so that the optical fiber can be placed in the artery (blood vessel model MX) and contact the blood flowing in the artery. Furthermore, the longitudinal extension, bending, and compression of the optical fiber follow the extension, bending, and compression of the artery.

[0043] The system includes a human coronary artery model connected to a flow control pump, which adjusts the flow pump to control the flow and velocity of blood. The FBG sensor is integrated with the vascular simulation system, and the vascular simulation system, optical fiber integration, and test pipeline are connected with a three-way connection. The FBG sensor is connected to the modem to measure the output wavelength and strain. Figure 1 .Three fiber 18 grating FBG sensor segments are integrated with the blood vessel model MX.

[0044] The FBG sensor is 3 optical fibers evenly arranged at 120 degrees around the deformable elastic central conduit Tube 1. There are 3 optical fibers (Fiber1, Fiber2, Fiber3), and 6 FBGSensor points are evenly distributed on each optical fiber, for a total of 18 FBG detection points.

[0045] The grating core diameter is 0.125mm, the grating area length is 5mm, and the distance is 10mm. The sensor grating process is to use ultraviolet light and phase mask template writing technology to make wavelength reflective optical devices on optical fibers. First, the excimer laser is used to carve the optical fiber string.

[0046] Through the optical fiber coating process, acrylic is coated with a diameter of 0.25mm, and then the optical fiber string is wrapped with a 0.9mm diameter PVC tight sleeve for tight packaging. The single-end pigtail length is 2.5m, and the other end is fused with an FC / APC connector. Figure 2 , 3 、4.

[0047] Since the space-bent and twisted blood vessels are not on the same plane, the narrow area is also not on the same plane. The grating points of the sensor of the present invention are arranged in the space area. Tube Ι is a central catheter (PVC tube) that can be bent and deformed but has elasticity. It is integrated with the Fiber sensor and can guide the Fiber sensor into the bent blood vessels. Three multi-core optical fibers (MCF) form a distributed measurement. Three optical fibers Fiber1, Fiber2, and Fiber3 are located on the outer surface of the elastic central catheter Tube Ι, evenly distributed at intervals of 120°.

[0048] It is very important that the sensor has the ability to bend and twist in space. The relationship between the deformable elastic central conduit and the optical fiber sensors FiberⅠ, FiberⅡ, and FiberⅢ of the present invention is as follows: the optical fiber sensor is placed on the outer surface of the deformable elastic central conduit, and the three optical fiber tight sleeves are bonded to the outer surface of the elastic central conduit Tube Ι, but the FBG grating area is not bonded to the conduit Tube Ι. Instead, the grating spacing area is bonded to the conduit Tube Ι. The FBG grating area should not be affected by the bonding point.

[0049] In order to form a spatial bending and twisting effect, during bonding, the elastic central catheter forms a non-contact area with the sensor's FBGSensor, so that the deformation of the grating area is not affected by the bonding of the contact area. Naturally formed flexible deformable tendons Tendons, which bend, stretch, or twist with the overall sensor to form a free expansion and contraction state.

[0050] When the elastic central catheter enters a curved blood vessel, the fiber sensor is guided through the cannula, and the fiber sensor has a certain spatial redundancy in the cannula, which can form a free degree of freedom of stretching and bending of the moving catheter, causing positive and negative strains of the FBG due to bending.

[0051] The experimental results show that the sensor can form The sensor can detect the multi-curved blood vessel model in depth. Since 6 FBG gratings are etched on each optical fiber, a total of 18 FBG grating measurement points can be achieved, which can realize multi-point and multi-directional measurement.

[0052] Based on the magnetic interference requirements of the MRI environment, the materials are non-magnetic materials: Silica, PVC, silicone, etc.

[0053] Three-fiber multi-core FBG sensor forms distributed measurement: The accuracy of the generated shape depends on the sensor's resolution of the deformation distribution. That is, the more information obtained along the arc length of the sensor, the better the deformation resolution effect, and the more accurate the constructed 3D shape. The shape is usually obtained by integrating multiple strain measurements along the fiber sensor due to the tensile strain or compressive strain formed by bending.

[0054] The FBG sensor consists of a multi-point grating area distributed longitudinally on the three optical fiber axes, with a light area length of 5mm and a grating area interval of 10mm, integrated in the circumscribed circle of Tube Ι, and cross section AA shows 3 FBGs. Three optical fibers Fiber1, Fiber2, and Fiber3. The three optical fibers Fiber1, Fiber2, and Fiber3 are located on the outer surface of Tube Ι, and 6 FBGSensor points are evenly distributed on each optical fiber, for a total of 18 FBG detection points. They are evenly distributed at intervals of 120°. The optical fiber sensor is placed on the outer surface of the deformable elastic central catheter, and the three optical fiber tight sleeves are bonded to the outer surface of the elastic central catheter Tube Ι, but the FBG grating area is not bonded to the catheter Tube Ι. Instead, the grating interval area is bonded to the catheter Tube Ι. The FBG grating area should not be affected by the bonding point. During bonding, the elastic central catheter and the FBGSensor of the sensor form a non-contact area, so that the deformation of the grating area is not affected by the bonding of the contact area. Naturally formed flexible and deformable tendons Tendons bend, stretch, or twist with the overall sensor to form a free expansion and contraction state.

[0055] The three-fiber grating area interval is bonded to the Tendons tube, and several bonding points are distributed to make it integrated with the Tube Ι catheter to achieve the telescopic bending of the fiber axis. All parts are fixed with medical glue. The glue used during assembly is Loctite4013, which is a transparent medical glue suitable for the assembly of medical equipment.

[0056] It also includes a catheter guide sleeve, which is concentric with Tube 1 to guide the sensor into the blood vessel. Tube 2 is sleeved on the circumscribed circle formed by three fibers to protect the fiber sleeve. It also includes a support rod for bearing external force support.

[0057] The sensor of the present invention can form spatial bending and twisting. First, the central conduit of the grating elasticity forms a non-contact area with the FBG Sensor of the sensor, so that the deformation of the grating area is not affected by the adhesion of the contact area. Naturally formed flexible and deformable tendons Tendons, which bend, stretch, or twist with the overall sensor to form a free expansion and contraction state. Second, all plastic materials are selected, which have certain flexibility and elasticity.

[0058] The sensor can measure spatial vascular stenosis: 18 grating points are arranged in a 120° distribution in the plane, but when the sensor can form a spatial bending and twisting, the grating points become a spatial layout. When the sensor moves in the blood vessel, it covers the entire inner wall of the blood vessel and can detect all stenotic areas.

[0059] The present invention also provides a detection method based on the above-mentioned Bragg sensor for detecting spatial curved blood vessel stenosis, comprising an assembly step: arranging a plurality of optical fiber sensors, each optical fiber sensor comprising a plurality of FBG sensors, and a spacer area being arranged between adjacent FBG sensors; a bonding step: the plurality of optical fiber sensors are distributed at equal intervals along the radial direction of a first elastic central catheter, and the optical fiber sensors are bonded to the outer surface of the first elastic central catheter through the spacer area; and a shape information acquisition step: acquiring the spatial shape information of the blood vessel based on the test results of the plurality of FBG sensors.

[0060] In the description of the present application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0061] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A Bragg sensor for detecting narrowing of curved blood vessels in space, characterized in that: The invention comprises a first elastic central catheter, a second elastic central catheter, an optical fiber sensor and an interventional device, wherein: There are three optical fiber sensors, and the radial directions of the three optical fiber sensors surrounding the first elastic central conduit are 120 degrees apart. Each optical fiber sensor is evenly distributed with six FBG sensors; a spacing area is provided between adjacent FBG sensors, the spacing area of ​​the optical fiber sensor is bonded to the first elastic central conduit, and the three optical fiber sensors are evenly spaced along the radial direction of the first elastic central conduit; The interventional device is disposed inside the first elastic central catheter; The second elastic central catheter is sleeved on the outside of the three optical fiber sensors; The optical fiber sensor further comprises a tight sleeve arranged outside the FBG sensor, wherein the tight sleeve is bonded to the outer surface of the first elastic central conduit; The FBG sensor is not in contact with the first elastic central catheter, and when the first elastic central catheter is bent in space, the FBG sensor can form a space bending torsion; The outer periphery of the FBG sensor is provided with an acrylic optical fiber coating layer, and the tight sleeve tightly wraps the acrylic optical fiber coating layer.

2. The Bragg sensor for detecting narrowing of curved blood vessels in space according to claim 1, characterized in that: One end of the optical fiber sensor is provided with a pigtail, and the other end is fused with an FC / APC connector.

3. The Bragg sensor for detecting narrowing of curved blood vessels in space according to claim 1, characterized in that: The first elastic central conduit and the second elastic central conduit are central conduits made of non-magnetic materials.

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