Force sensor and force sensing catheter

Abstract

The utility model relates to a force sensor and a force sensing catheter. The force sensor comprises a sensor body (100), and the sensor body (100) comprises a first section (10), a second section (20) and a middle section (30) which is located between the first section (10) and the second section (20) and connects the first section (10) and the second section (20). At least a portion of the outer surface of the intermediate section (30) is recessed inwardly relative to the outer surface of the first section (10) and the outer surface of the second section (20) to form a gap (40) between the first section (10) and the second section (20). The sensor body (100) further comprises an annular portion defining at least a portion of an axial boundary of the gap (40), where the thickness of the annular portion is less than the width of its annular face.

Description

Technical Field

[0001] The present disclosure relates to the field of medical devices, and in particular to a force sensor. The force sensor is particularly suitable for a diagnosis and treatment system based on a catheter. The present disclosure also relates to a force sensing catheter having the force sensor. Background Art

[0002] Atrial fibrillation (AF) is one of the most common arrhythmias in clinical practice, with a prevalence of 0.4% to 1% in the general population, and its incidence rate increases significantly with age. The disease can lead to high disability and mortality rates. Catheter ablation can cure atrial fibrillation (AF) and improve patients' symptoms, and the effectiveness of ablation is closely related to the degree of contact between the ablation catheter and the atrial tissue. Permanent transmural damage to all atrial fibrillation ablation points is the key to ensuring a high success rate of the operation and reducing recurrence, and it is also the difficulty of ablation. The research and development of the new pressure contact monitoring catheter focuses on improving tissue adhesion, improving the safety of catheter operation, and being able to better control the size of the damage at the ablation point, thereby increasing the effectiveness of ablation.

[0003] It is desirable to provide a force sensor that can be used in this scenario, which has low sensitivity differences in various directions and high overall accuracy. Utility Model Content

[0004] In response to the above-mentioned problems and needs, the present disclosure proposes a force sensor, which solves the above-mentioned problems and brings other technical effects by adopting the following technical features.

[0005] The present disclosure provides a force sensor, the force sensor comprising a sensor body, the sensor body comprising a first section, a second section, and an intermediate section located between the first section and the second section and connecting the first section and the second section. At least a portion of the outer surface of the intermediate section is inwardly recessed relative to the outer surface of the first section and the outer surface of the second section to form a gap between the first section and the second section. The sensor body further comprises an annular portion, the annular portion defining at least a portion of the axial boundary of the gap, wherein the thickness of the annular portion is less than the width of its annular surface.

[0006] According to one embodiment, the annular portion includes a first annular portion and a second annular portion, wherein the first annular portion defines a portion of the axial boundary of the gap and connects the first end of the middle section with the first section, and the second annular portion defines a portion of the axial boundary of the gap and connects the second end of the middle section with the second section.

[0007] According to an embodiment, the annular portion extends in a transverse direction perpendicular to the axial direction or at an angle between 0 and 15° relative to the transverse direction.

[0008] According to an embodiment, the first section, the second section and the middle section each have a side wall surrounding the hollow portion, wherein the side wall of the middle section is parallel to the side wall of the first section and the side wall of the second section.

[0009] According to one embodiment, the first segment, the second segment and the middle segment all have a circular cross-section, wherein the outer diameter of the middle segment is smaller than the inner diameter of the first segment and smaller than the inner diameter of the second segment; and the first segment and the second segment have the same inner diameter and outer diameter.

[0010] According to an embodiment, one of the first segment and the second segment is directly connected to the middle segment, and the other of the first segment and the second segment is connected to the middle segment via the annular portion.

[0011] According to one embodiment, the middle section has a first recessed portion, a second recessed portion and a central section connecting the first recessed portion and the second recessed portion, and the first recessed portion and the second recessed portion are both recessed relative to the outer surfaces of the first section, the second section and the central section to form two gaps; wherein the annular portion includes a first annular portion and a second annular portion, the first annular portion connects the first end of the central section and the first recessed portion, and the second annular portion connects the second end of the central section and the second recessed portion.

[0012] According to an embodiment, the force sensor further comprises an optical sensor device extending through the first section and the second section in the axial direction.

[0013] According to one embodiment, the optical sensor device comprises: a plurality of reflective members passing through the first section in an axial direction; and a plurality of optical fibers passing through the second section in an axial direction and the number of the optical fibers being the same as the number of the reflective members, wherein one end of each reflective member extends into the gap and is opposite to an end of each optical fiber extending into the gap.

[0014] According to one embodiment, the width-to-thickness ratio of the annular portion is between 2-3.

[0015] According to one embodiment, the sensor body is an integrated structure.

[0016] The present disclosure also provides a force sensing catheter, comprising a flexible elongated body having a distal end; and a force sensor according to any one of the above items, the force sensor being arranged at the distal end within the flexible elongated body.

[0017] The best embodiments for implementing the present disclosure will be described in more detail below with reference to the accompanying drawings so that the features and advantages of the present disclosure can be easily understood. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings of the embodiments of the present disclosure are briefly introduced below. The drawings are only used to show some embodiments of the present disclosure, but not to limit all embodiments of the present disclosure thereto.

[0019] Figure 1A , 1B , 1C, 1D, 1E show various views of a force sensor according to a first embodiment of the present disclosure;

[0020] Figure 2A , 2B 2C, 2D, and 2E show various views of the force sensor according to the first embodiment of the present disclosure, compared to Figure 1A , 1B , 1C, 1D, 1E, the optical sensor device is omitted;

[0021] Figure 3A , 3B 3C shows various views of a force sensor according to a second embodiment of the present disclosure;

[0022] Figure 4A , 4B 4C shows various views of a force sensor according to a third embodiment of the present disclosure;

[0023] Figure 5A , 5B 5C shows various views of a force sensor according to a fourth embodiment of the present disclosure;

[0024] Figure 6 shows a dimensioned cross-sectional view of a force sensor according to a first embodiment of the present disclosure;

[0025] Fig. 7A , 7B 7C and 7D show various views of a force sensor according to a fifth embodiment of the present disclosure;

[0026] Fig. 8A , 8B , 8C, 8D, 8E show various views of a force sensor according to a sixth embodiment of the present disclosure;

[0027] Fig.9A , 9B 9C show various views of a force sensor according to a seventh embodiment of the present disclosure.

[0028] Reference numerals list

[0029] 100 sensor body

[0030] 10 First Segment

[0031] 20 Second Segment

[0032] 30 Middle section

[0033] 31 First end of the middle section

[0034] 32 Second end of the middle section

[0035] 41 First annular part

[0036] 42 Second annular portion

[0037] 40 Gap

[0038] 33 First recess

[0039] 34 Second recessed portion

[0040] 35 Central Area

[0041] 351 The first end of the central section

[0042] 352 The second end of the central section

[0043] 36 Accommodation

[0044] 200 optical sensors

[0045] 51 Reflective component

[0046] 52 Fiber Optic

[0047] 43 holes DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solution and advantages of the technical solution of the present disclosure clearer, the technical solution of the embodiment of the present disclosure will be clearly and completely described in conjunction with the drawings of the specific embodiments of the present disclosure. The same figure marks in the drawings represent the same parts. It should be noted that the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0049] Compared to the embodiments shown in the drawings, feasible implementations within the scope of the present disclosure may have fewer components, other components not shown in the drawings, different components, differently arranged components, or differently connected components, etc. In addition, two or more components in the drawings may be implemented in a single component, or a single component shown in the drawings may be implemented as multiple separate components.

[0050] Unless otherwise defined, the technical terms or scientific terms used herein shall have the usual meanings understood by persons of ordinary skill in the field to which the present disclosure belongs. The words "first", "second" and similar words used in the patent application specification and claims of the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one" or "one" do not necessarily indicate a quantity restriction. Words such as "include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0051] In various embodiments of the present disclosure, including those shown in the accompanying drawings and those not shown in the accompanying drawings, the sensor body of the force sensor includes at least two sections that are deformable relative to each other, and the two sections may be cylindrical or cylindrical-like structures. The two parts are connected by an annular portion, and the annular portion is configured so that the deformation between the two sections that are movable relative to each other mainly occurs in the annular portion.

[0052] First refer to Figure 1A-Figure 2E The force sensor of the first embodiment of the present disclosure is described. It should be noted that in the present disclosure, the features described for any embodiment can also be used in other embodiments without causing any contradiction.

[0053] Figure 1A , 1B , 1C, 1D, and 1E respectively show a side view, a stereoscopic view, a side view from another angle, a cross-sectional view taken along the center plane, and a top view of the force sensor. Figures 1A-1E , Figure 2A-2E Only the sensor body 100 is shown, and the optical sensor device 200 is omitted. Figure 2A , 2B 2C, 2D, and 2E respectively show a side view, a cross-sectional view taken along a central plane, a stereoscopic view, a top view, and a cross-sectional view passing through the middle section 30 of the sensor body 100.

[0054] The force sensor includes a sensor body 100 and an optical sensor device 200 held by the sensor body 100. The sensor body 100 includes a first section 10, a second section 20, and an intermediate section 30 located between and connecting the first section 10 and the second section 20. In the present disclosure, the first section 10 may also be referred to as the distal end of the force sensor, and the second section 20 may also be referred to as the proximal end of the force sensor. Each of the first section 10, the second section 20, and the intermediate section 30 is preferably a hollow cylindrical structure surrounded by a side wall, in particular a cylindrical structure with a circular cross section.

[0055] The outer surface of the middle section 30 is inwardly concave relative to the outer surface of the first section 10 and the outer surface of the second section 20 to form a gap 40 between the first section 10 and the second section 20. When a force is applied to the distal end of the force sensor, i.e., the position of the first section 10, the first section 10 is deformed relative to the second section 20, so that the size of the gap 40 in the axial direction also changes.

[0056] The sensor body 100 further includes a first annular portion 41 and a second annular portion 42, which define two axial boundaries of the gap 40. The first annular portion 41 connects the first end 31 of the middle section 30 and the first section 10, and the second annular portion 42 connects the second end 32 of the middle section 30 and the second section 20. In the present disclosure, the first annular portion 41 and the second annular portion 42 may be collectively referred to as annular portions. In the present disclosure, annular portions are thin-walled structures, that is, their thickness is less than the width of their annular surfaces.

[0057] Due to the thin-walled shape, when the distal end of the force sensor is subjected to force, the deformation between the first section 10 and the second section 20 will mainly occur in the first annular portion 41 and the second annular portion 42. Since the first annular portion 41 and the second annular portion 42 are not located on the cylindrical outer surface of the sensor body 100, but are located in a very hidden position that is difficult to touch during operation, the deformed part is prevented from being directly subjected to force, thereby improving the measurement accuracy of the force applied to the sensor.

[0058] Moreover, since the annular portion is a symmetrical annular structure with the central axis of the sensor body 100 as the central axis, the cross-sectional inertia moment of the sensor body 100 in all directions can be completely equal, thereby minimizing the sensitivity difference of sensors in all directions and improving the overall accuracy of the sensor.

[0059] Preferably, the thickness of the annular portion is also smaller than the thickness of any one of the first section 10 and the second section 20. More preferably, the thickness of the annular portion is smaller than the thickness of any one of the first section 10, the second section 20 and the middle section 30.

[0060] The thinness of the annular portion can also be specifically expressed by the width-to-thickness ratio of the annular portion. The width of the annular portion, that is, the width of the annular surface of the annular portion, is equal to the distance between the outer peripheral edge and the inner peripheral edge of the annular portion, and is also equal to the distance between the two components it connects. Figure 6 For example, the width of the first annular portion 41 is the distance between the first segment 10 and the middle segment 30, and the width of the second annular portion 42 is the distance between the second segment 20 and the middle segment 30. In the first embodiment, the width of the annular portion is also equal to the length of the annular portion extending in the radial direction. Figure 6 Marked with w.

[0061] The thickness of the annular portion is the wall thickness of the annular portion. For an annular portion extending in the transverse direction, its wall thickness can be measured in the axial direction. For an annular portion of non-uniform thickness, its thickness can be its average thickness, or its thickness at the middle position. Figure 6 Marked with d.

[0062] The width-to-thickness ratio of the annular portion is greater than 1, preferably, the width-to-thickness ratio of the annular portion is greater than or equal to 2, or greater than or equal to 2.5, or greater than or equal to 3. Preferably, the width-to-thickness ratio of the annular portion is between 2-4, and particularly preferably, the width-to-thickness ratio of the annular portion is between 2-3.

[0063] The force sensor disclosed in the present invention has a very small size. The outer diameter of the sensor body 100 is generally in the range of 1.5 mm to 3 mm, the length of the sensor body 100 is in the range of 1 mm to 8 mm, and the thickness of the annular portion is in the range of 0.05 mm to 0.1 mm, for example, 0.06 mm. In this case, if the width-to-thickness ratio is too high, the manufacturing process will be too difficult and the structural strength of the sensor body 100 will be reduced. By setting the width-to-thickness ratio w / d of the annular portion between 2 and 3, sufficient deformation can be provided to improve the accuracy of the sensor, and the structural strength of the sensor is also ensured, reducing the manufacturing difficulty.

[0064] In this first embodiment, the first annular portion 41 and the second annular portion 42 both extend in a transverse direction perpendicular to the axial direction of the sensor body 100. In other embodiments, the first annular portion 41 and / or the second annular portion 42 may be at an angle of between 0 and 30°, particularly between 0 and 15°, and more preferably between 0 and 10° relative to the transverse direction. By making the annular portions extend substantially parallel to the transverse direction, it can help ensure that the deformation between the first segment 10 and the second segment 20 mainly occurs in the first annular portion 41 and the second annular portion 42.

[0065] The sensor body 100 preferably satisfies one or more of the following features:

[0066] 1. The sensor body 100 is an integrated structure.

[0067] 2. The first section 10 , the second section 20 and the middle section 30 all have circular cross sections, wherein the outer diameter of the middle section 30 is smaller than the inner diameter of the first section 10 and smaller than the inner diameter of the second section 20 .

[0068] 3. The side walls of the middle section 30 are parallel to the side walls of the first section 10 and the side walls of the second section 20 .

[0069] 4. The first section 10 and the second section 20 have the same inner diameter and outer diameter.

[0070] By means of these features, and in particular the combination of two or more of these features, the sensor body 100 can be manufactured in a simple manner using a standard cylindrical blank.

[0071] by Figure 2A-2E Taking the structure of the sensor body 100 shown as an example, the manufacturing method may include: (1) providing a cylindrical blank with a certain wall thickness; (2) widening the inner diameter at the first end of the cylindrical blank to form the inner surface of the first section 10; (3) widening the inner diameter at the second end of the cylindrical blank to form the inner surface of the second section 20; (4) machining a groove from the outer wall of the cylindrical blank to form the gap 40. The aforementioned steps (2), (3), and (4) do not have to be performed in the order described, but can be performed in any order.

[0072] Among them, the manufacturing methods include but are not limited to laser processing, oil-cut wire processing, electric discharge machining, etc.

[0073] The optical sensor device 200 of the force sensor is held by the sensor body 100 and is configured to sense the deformation of the sensor body 100 caused by the force and transmit a signal representing the deformation. In some embodiments, the optical sensor device 200 is a combination of a reflective member 51 and an optical fiber 52. In other embodiments, the optical sensor device 200 is a Bragg grating of the optical fiber 52.

[0074] There may be a plurality of optical sensor devices 200, and they are accommodated in the accommodating portion 36. In some embodiments, the accommodating portion 36 may be a through hole, such as a circular, elliptical, polygonal, square, rectangular, or irregularly shaped through hole. In other embodiments, the accommodating portion 36 may be a groove open to the outer surface of the sensor body 100, and the cross-sectional shape of the groove may be composed of a circular arc, a curve, a straight line, and a combination of curves. Figure 2C , 2D As shown in FIG. 2E , the first section 10 and the second section 20 each have three receiving portions 36 , and for any section, the three receiving portions 36 are evenly arranged at positions close to the circumference.

[0075] The optical sensor device 200 can be a combination of a reflective component 51 and an optical fiber 52, wherein a plurality of reflective components 51 pass through the first segment 10 along the axial direction, and a plurality of optical fibers 52 pass through the second segment 20 along the axial direction and their number is the same as the number of the reflective components 51, so that the reflective components 51 and the optical fibers 52 are in a one-to-one correspondence. Figures 1A-1E The embodiment shown is such a case. One end of each reflective member 51 extends into the gap 40 and is opposite to the end of each optical fiber 52 extending into the gap 40. There is a gap between the end of the reflective member 51 and the end of the optical fiber 52. The optical fiber 52 is configured to emit light to the reflective member 51 and collect light reflected from the reflective member 51. Light is emitted through the end face of the optical fiber 52 and passes through the gap to reach the end face of the corresponding reflective member 51. Similarly, the reflected light from the reflective member 51 passes through the gap to reach the optical fiber 52. When the sensor is subjected to force, deformation occurs at the annular portion between the first section 10 and the second section 20, resulting in a change in the distance between the end face of the optical fiber 52 and the end face of the reflective member 51. The change in the distance can be used to obtain the magnitude and direction of the force applied to the sensor, as described below.

[0076] The force sensor disclosed in the present invention may adopt the following three demodulation schemes.

[0077] The first method is to use the principle of white light interference demodulation, which involves the case where the optical sensor device 200 is a reflective component 51 and an optical fiber 52. When the sensor is subjected to force at the far end, the annular portion between the second section 20 and the first section 10 is deformed, thereby causing the distance between the reflective component 51 and the optical fiber 52 to change. The change in the distance between the reflective component 51 and the optical fiber 52 at three or more positions in the gap 40 is calculated by the principle of white light interference demodulation, and the magnitude and direction of the force at the far end can be calculated.

[0078] The second method is to use the principle of light intensity demodulation, which involves the case where the optical sensor device 200 is a reflective component 51 and an optical fiber 52. When the sensor is subjected to force at the far end, the annular portion of the second section 20 and the first section 10 deforms, causing the distance between the reflective component 51 and the optical fiber 52 to change. The change in distance causes the intensity of light reflected from the end face of the reflective component 51 received by the optical fiber 52 to change. The magnitude and direction of the force at the far end can be calculated by the change in light intensity at three or more positions distributed in the gap 40.

[0079] The third method is to use the fiber 52 Bragg grating principle. This scheme involves the case where the optical sensor device 200 is a fiber 52 Bragg grating. The two ends of the fiber 52 Bragg grating are fixed in the accommodating parts 36 of the second section 20 and the first section 10 respectively. When the sensor is subjected to force at the far end, the annular part between the second section 20 and the first section 10 is deformed, thereby causing the fiber 52 Bragg grating to be subjected to tension or pressure. When the fiber 52 Bragg grating is subjected to tension or pressure, its central wavelength will change accordingly. By measuring the change in the central wavelength of the fiber 52 Bragg grating distributed at 3 or more positions in the gap 40, the magnitude and direction of the force at the far end can be calculated.

[0080] Refer to the following Figure 3A-Figure 5C The force sensors according to other embodiments of the present disclosure are described. In these embodiments, the first section 10, the second section 20, and the middle section 30 are arranged similarly to the first embodiment, and each has two annular portions. The difference between these embodiments and the first embodiment mainly lies in the specific shape of the annular portions.

[0081] Figure 3A , 3B , 3C show various views of a force sensor according to a second embodiment of the present disclosure. In this second embodiment, the annular portion has an uneven wall thickness. In the cross-sectional view along the central plane of the sensor body 100, the first annular portion 41 and the second annular portion 42 have a right-angled trapezoidal shape. The wall thickness of the first annular portion 41 and the second annular portion 42 is thinner as it is closer to the central axis of the force sensor, and thicker as it is farther away from the central axis of the force sensor. The surfaces of the first annular portion 41 and the second annular portion 42 close to the gap 40 extend roughly along the lateral direction of the sensor body 100, and the surfaces of the first annular portion 41 and the second annular portion 42 away from the gap 40 form an acute angle with respect to the lateral direction of the sensor body 100. Alternatively, both surfaces of the first annular portion 41 and the second annular portion 42 may be formed at an acute angle relative to the transverse direction of the sensor body 100, or the surfaces of the first annular portion 41 and the second annular portion 42 close to the gap 40 may be formed at an acute angle relative to the transverse direction of the sensor body 100, and the surfaces of the first annular portion 41 and the second annular portion 42 away from the gap 40 may extend substantially along the transverse direction of the sensor body 100. By setting the uneven wall thickness of the annular portion, it is more conducive to reducing the difficulty of processing the force sensor.

[0082] Figure 4A , 4B4C show various views of a force sensor according to a third embodiment of the present disclosure. In the third embodiment, in a cross-sectional view along the center plane of the sensor body 100, the first annular portion 41 and the second annular portion 42 have a parallelogram shape. The first annular portion 41 and the second annular portion 42 form an acute angle with respect to the lateral direction of the sensor body 100. The acute angle is preferably less than 30°, and more preferably, less than 15°. By allowing the annular portion to have an inclination angle controlled within a certain range, it is possible to ensure that the deformation of the first section 10 relative to the second section 20 mainly occurs in the annular portion, while allowing the processing accuracy requirements of the sensor body 100 to be reduced.

[0083] Figure 5A , 5B 5C shows various views of a force sensor according to a fourth embodiment of the present disclosure. In this fourth embodiment, in a cross-sectional view along the central plane of the sensor body 100, the first annular portion 41 and the second annular portion 42 have irregular shapes. The first annular portion 41 and the second annular portion 42 are not flat thin walls, but have annular surfaces composed of curved surfaces. In this embodiment, the size of the gap 40 increases in a direction away from the central axis, and the two axial sides of the gap 40 are defined by curves. This solution can also ensure that the deformation of the first section 10 relative to the second section 20 mainly occurs in the annular portion, while allowing the processing accuracy requirements of the sensor body 100 to be reduced.

[0084] Figure 7A-7D A force sensor according to a fifth embodiment of the present disclosure is shown. This embodiment has only one annular portion, namely the first annular portion 41. Among them, the second section 20 is directly connected to the middle section 30, and the first section 10 is connected to the middle section 30 through the annular portion. It can be understood that in an embodiment not shown, the first section 10 can be directly connected to the middle section 30, and the second section 20 can be connected to the middle section 30 through the annular portion. In addition, in an embodiment not shown, the second section can be set to have an outer diameter smaller than the outer diameter of the first section, or even equal to the outer diameter of the middle section 30.

[0085] As shown in this embodiment, the thickness of the section directly connected to the middle section 30, here the second section 20, is set so that its inner peripheral surface is continuous with the inner peripheral surface of the middle section 30. In this way, the manufacturing steps can be simplified because the step of widening the inside of the second section 20 can be omitted.

[0086] The wall thickness of the first section 10 is set so that its inner peripheral surface is farther from the central axis than the outer peripheral surface of the middle section 30 to leave space for the annular portion.

[0087] Figure 8A-8EA force sensor according to a sixth embodiment of the present disclosure is shown. Unlike the previous embodiments, this embodiment has two gaps 40 .

[0088] Specifically, the sensor body 100 of the sixth embodiment can be divided into three sections, a first section 10, a second section 20, and a middle section 30 connecting the first section 10 and the second section 20. The middle section 30 has a first concave portion 33, a second concave portion 34, and a central section 35 connecting the first concave portion 33 and the second concave portion 34. The first concave portion 33 and the second concave portion 34 are both concave relative to the outer surfaces of the first section 10, the second section 20, and the central section 35 to form two gaps 40.

[0089] The annular portion of this embodiment includes a first annular portion 41 and a second annular portion 42 . The first annular portion 41 connects the first end 351 of the central section 35 and the first recessed portion 33 , and the second annular portion 42 connects the second end 352 of the central section 35 and the second recessed portion 34 .

[0090] By forming two gaps 40 and forming annular portions beside the two gaps 40 , it is more conducive to the deformation of the entire sensor body 100 and to the improvement of the overall measurement accuracy.

[0091] In the sixth embodiment, it is preferred that the first section 10 , the first recessed portion 33 , the second section 20 , and the second recessed portion 34 have the same inner diameter to simplify the processing steps.

[0092] When manufacturing the sensor of the sixth embodiment, only the following steps are required: (1) providing a cylindrical blank; (2) machining the first concave portion 33; (3) machining the second concave portion 34; (4) widening the middle section of the middle section 30. Steps (2) to (4) do not have to be performed in the order described, but may be performed in any order.

[0093] Figure 9A-9C FIG. 7 shows a force sensor according to a seventh embodiment of the present disclosure. This embodiment is similar to the first embodiment, except that the annular portion in this embodiment is discontinuous, but is divided into two or more fan-shaped segments. In the embodiment with two fan-shaped segments, it is preferred that the two fan-shaped segments are identical. For more than two fan-shaped segments, it is preferred that they are evenly distributed along the circumference to reduce the sensitivity difference of the sensor in each direction. The fan-shaped segments can be separated by holes 43, such as Fig. 9C shown.

[0094] The force sensor of any embodiment of the present disclosure may be disposed in a force sensing catheter having a flexible, elongated body with a distal end, and the force sensor is arranged at the distal end within the flexible, elongated body. The force sensor compresses or bends in response to a contact force applied to the distal end of the flexible, elongated body, for example, a contact force generated when the distal end contacts the wall of a blood vessel or an organ. The force sensing catheter may have a width and length suitable for insertion into a human blood vessel or organ. The force sensing catheter may include a proximal portion, a middle portion, and a distal portion, and the distal portion may include an end actuator that accommodates the force sensor. The specific structure of the force sensing catheter used by the force sensor of the present disclosure is not limited, and depending on the application, the force sensing catheter may be a hollow structure (i.e., having an inner cavity) or a non-hollow structure (i.e., having no inner cavity).

[0095] The exemplary implementation scheme of the present disclosure is described in detail above with reference to the preferred embodiments. However, it can be understood by those skilled in the art that, without departing from the concept of the present disclosure, various modifications and variations can be made to the above-mentioned specific embodiments, and various technical features and structures proposed in the present disclosure can be combined in various ways without exceeding the protection scope of the present disclosure, which is determined by the attached claims.

Claims

1. A force sensor, characterized in that: The force sensor comprises a sensor body (100), wherein the sensor body (100) comprises a first section (10), a second section (20), and an intermediate section (30) located between the first section (10) and the second section (20) and connecting the first section (10) and the second section (20); At least a portion of the outer surface of the middle section (30) is recessed inward relative to the outer surface of the first section (10) and the outer surface of the second section (20) to form a gap (40) between the first section (10) and the second section (20); The sensor body (100) further comprises an annular portion defining at least a portion of an axial boundary of the gap (40), wherein a thickness of the annular portion is smaller than a width of an annular surface thereof.

2. The force sensor according to claim 1, characterized in that The annular portion includes a first annular portion (41) and a second annular portion (42), wherein the first annular portion (41) defines a portion of an axial boundary of the gap (40) and connects a first end portion (31) of the middle section (30) and the first section (10), and the second annular portion (42) defines a portion of an axial boundary of the gap (40) and connects a second end portion (32) of the middle section (30) and the second section (20).

3. The force sensor according to claim 1, wherein: The annular portion extends in a transverse direction perpendicular to the axial direction or at an angle between 0 and 15° relative to the transverse direction.

4. The force sensor according to claim 1, wherein: The first section (10), the second section (20) and the middle section (30) all have side walls surrounding the hollow portion. Wherein, the side wall of the middle section (30) is parallel to the side wall of the first section (10) and the side wall of the second section (20).

5. The force sensor according to claim 1, wherein: The first section (10), the second section (20) and the middle section (30) all have circular cross-sections, wherein the outer diameter of the middle section (30) is smaller than the inner diameter of the first section (10) and smaller than the inner diameter of the second section (20); and The first section (10) and the second section (20) have the same inner diameter and outer diameter.

6. The force sensor according to claim 1, wherein: One of the first section (10) and the second section (20) is directly connected to the middle section (30), The other of the first section (10) and the second section (20) is connected to the middle section (30) via the annular portion.

7. The force sensor according to claim 1, wherein: The middle section (30) has a first concave portion (33), a second concave portion (34) and a central section (35) connecting the first concave portion (33) and the second concave portion (34), and the first concave portion (33) and the second concave portion (34) are both concave relative to the outer surfaces of the first section (10), the second section (20) and the central section (35) to form two gaps (40); The annular portion includes a first annular portion (41) and a second annular portion (42), wherein the first annular portion (41) connects the first end (351) of the central portion (35) and the first recessed portion (33), and the second annular portion (42) connects the second end (352) of the central portion (35) and the second recessed portion (34).

8. The force sensor according to claim 1, wherein: The force sensor further comprises an optical sensor device (200) extending through the first section (10) and the second section (20) along the axial direction.

9. The force sensor according to claim 8, characterized in that The optical sensor device (200) comprises: a plurality of reflecting members (51) passing through the first section (10) in an axial direction; and a plurality of optical fibers (52) which pass through the second section (20) in the axial direction and whose number is the same as the number of the reflecting members (51); One end of each reflecting member (51) extends into the gap (40) and is opposite to the end of each optical fiber (52) extending into the gap (40).

10. The force sensor according to claim 1, wherein: The width-to-thickness ratio of the annular portion is between 2 and 3.

11. The force sensor according to claim 1, wherein: The sensor body (100) is an integrated structure.

12. A force sensing catheter, characterized in that: include: a flexible elongated body having a distal tip; and The force sensor according to any one of claims 1-11, wherein the force sensor is arranged at the distal end within the flexible slender body.

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