Force sensor and force sensing conduit

Abstract

This disclosure relates to a force sensor and a force-sensing conduit. The force sensor includes a structural member defining a longitudinal axis, the structural member including a proximal end and a distal end, the structural member extending from the proximal end toward the distal end along the longitudinal axis; a slit defining between the proximal and distal ends, the slit extending about the longitudinal axis from a starting position on a side of the structural member to a terminating position on a side of the structural member, the starting position being closer to the proximal end in the longitudinal axis direction than the terminating position, the size of the slit varying in response to changes in the force applied to the structural member; and a plurality of optical fibers operatively coupled to the structural member. The force sensor of this disclosure improves the sensitivity and accuracy of force sensing.

Description

Technical Field

[0001] This disclosure relates to force sensors and force sensing conduits. Background Technology

[0002] Over the years, catheter-based diagnostic and therapeutic systems have been used to explore and treat various organs or blood vessels.

[0003] The effectiveness of such catheters typically depends on the tissue contact between the catheter and the wall of an organ or blood vessel. For example, catheter ablation can cure atrial fibrillation, and the effectiveness of the ablation is closely related to the degree of contact between the ablation catheter and the atrial tissue. Gaps between the catheter's distal actuator and the tissue wall can lead to ineffective treatment and insufficient ablation of the tissue area. If the distal actuator applies excessive force to the tissue wall, it may unintentionally puncture the tissue. Therefore, a force-measuring system is needed to provide feedback on the force applied by the catheter to the tissue wall at the treatment site.

[0004] In one known force sensor design, the force sensor comprises a structural member defined by segments connected to each other via connectors, with multiple segments arranged in series and gaps defined within the structural member. A drawback of this type of force sensor is its low sensitivity and accuracy in force measurement.

[0005] Improving the sensitivity and accuracy of force sensors in sensing force has become an urgent problem to be solved. Summary of the Invention

[0006] Therefore, the object of this disclosure is to provide a force sensor that improves the accuracy of force sensing.

[0007] The above objective is achieved by means of a force sensor and a force sensing conduit as described below.

[0008] This disclosure relates to a force sensor, comprising:

[0009] A structural member defining a longitudinal axis, the structural member including a proximal end and a distal end, the structural member extending from the proximal end along the longitudinal axis toward the distal end;

[0010] A slit is defined between the proximal end and the distal end, the slit extending about the longitudinal axis from a starting position on the side of the structural member to a terminating position on the side of the structural member, the starting position being closer to the proximal end in the longitudinal axis direction than the terminating position, and the size of the slit changing in response to changes in the force applied to the structural member;

[0011] Multiple optical fibers operatively connected to the structural member.

[0012] In one embodiment, the rotational interval between the starting position and the ending position about the longitudinal axis is greater than 180°.

[0013] In one embodiment, the distance between the starting position and the ending position along the longitudinal axis is 0.5-1.5 mm.

[0014] In one embodiment, the slit size is 0.1-0.3 mm, and the slit size is the distance between the distal surface of the proximal end and the proximal surface of the distal end along the longitudinal axis.

[0015] In one embodiment, the slit comprises a spiral slit.

[0016] In one embodiment, the structural member comprises a hollow tube.

[0017] In one embodiment, each of the plurality of optical fibers includes an optical fiber end, and a gap is formed between the optical fiber end and the distal end or a reflective member disposed at the distal end, the operating size of the gap changing in response to a change in the size of the slit.

[0018] In one embodiment, each of the plurality of optical fibers includes an integrated fiber Bragg grating sensor.

[0019] This disclosure also proposes a force-sensing conduit, comprising:

[0020] A flexible, elongated body with a distal end; and

[0021] According to any of the above, the force sensor is arranged near the distal end within the flexible elongated body.

[0022] This disclosure also provides a method for manufacturing a force sensor, comprising:

[0023] A structural member defining a longitudinal axis is provided, the structural member including a proximal end and a distal end, the structural member extending from the proximal end along the longitudinal axis toward the distal end;

[0024] A slit is formed between the proximal end and the distal end, the slit extending about the longitudinal axis from a starting position on the side of the structural member to a terminating position on the side of the structural member, the starting position being closer to the proximal end in the longitudinal axis direction than the terminating position, and the size of the slit changing in response to changes in the force applied to the structural member;

[0025] Multiple optical fibers are operatively connected to the structural member.

[0026] This disclosure has the following advantages: the slit extends from the starting position on the side of the structural member to the ending position on the side of the structural member by rotating around the longitudinal axis. The starting position is closer to the proximal end in the longitudinal axis direction than the ending position, thereby improving the sensitivity to lateral forces in the x-axis direction. The ratio of the sensor's sensitivity to lateral forces in the y-axis direction to its sensitivity to lateral forces in the x-axis direction is less than 3 times, thereby improving the overall accuracy of the sensor. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings of the embodiments of this disclosure will be briefly described below. The drawings are merely illustrative of some embodiments of this disclosure and are not intended to limit the scope of all embodiments of this disclosure. In the drawings:

[0028] Figure 1 A schematic diagram of a force sensor with a slit transverse to the longitudinal axis is shown.

[0029] Figure 2 A top view of a force sensor with a slit transverse to the longitudinal axis is shown;

[0030] Figure 3 A schematic diagram of the structure of a force sensor according to an embodiment of the present disclosure is shown;

[0031] Figure 4 It shows Figure 3 Left view of the force sensor;

[0032] Figure 5 It shows Figure 3 Right view of the force sensor;

[0033] Figure 6 It shows Figure 3 A top view of the force sensor;

[0034] Figure 7 A schematic diagram of the structure of a force sensor according to another embodiment of the present disclosure is shown;

[0035] Figure 8 It shows Figure 7 Front view of the force sensor;

[0036] Figure 9 It shows Figure 7 The deformation of the force sensor under lateral force.

[0037] 10-Longitudinal axis 11-Proximal end 111-Distal surface 12-Distal end 121-Proximal surface 13-Slit A-Starting position B-Ending position 14-Groove 15-Connector 2-Optical fiber 21-Optical fiber end 3-Gap 4-Reflective member 41-Reflective member end Implementation

[0038] To make the objectives, technical solutions, and advantages of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. The same reference numerals in the drawings represent the same components. It should be noted that the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0039] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not necessarily indicate a quantity limitation. The terms “comprising,” “including,” or “having,” and similar terms mean that the element or object preceding the word encompasses the element or object listed following the word and its equivalents, without excluding other elements or objects. The terms “connected” or “connected,” and similar terms are not limited to the physical or mechanical connection or connection shown in the drawings, but may include equivalent connections or connections, whether direct or indirect. The terms “upper,” “lower,” “left,” and “right,” etc., are used only to indicate relative positional relationships, which may change accordingly when the absolute position of the described object changes.

[0040] Figures 1 to 2 A force sensor with a slit transverse to the longitudinal axis is shown. The slit extends laterally through most of the structural member to form a connection. The connection is a cylindrical connection with a circular arc-shaped cross-section. In the figure, 1 is the slit transverse to the longitudinal axis, and 1' is the cylindrical connection with a circular arc-shaped cross-section. The cross-section of the connection is shown in the shaded area in the figure. The slit is oriented substantially perpendicular to the longitudinal axis or extends at an acute angle relative to the longitudinal axis.

[0041] The cross-section of a structural member has orthogonal axes xx and yy. On the cross-section, axis xx marks the direction in which the structural member has the least sensitivity to lateral forces, while axis yy passes through the longitudinal axis. Lateral forces along the yy axis cause the connection to bend about the axis of inertia xx, resulting in deflection of the structural member through the bending of the connection. However, lateral forces along the xx axis tend to cause the structural member to twist rather than deflect. This results in the sensitivity to lateral forces along the xx axis being much lower than the sensitivity to lateral forces along the yy axis, limiting the sensitivity and accuracy of the force sensor.

[0042] The following is for reference. Figures 3 to 9 A detailed description of embodiments of the force sensor according to this disclosure is provided.

[0043] In one embodiment of this disclosure, a force sensor includes:

[0044] A structural member defining a longitudinal axis 10 and including a proximal end 11 and a distal end 12, the structural member extending from the proximal end 11 toward the distal end 12 along the longitudinal axis 10; a slit 13 is defined between the proximal end 11 and the distal end 12, the slit 13 extending from a starting position A on the side of the structural member about the longitudinal axis 10 to a terminating position B on the side of the structural member, the starting position A being closer to the proximal end 11 in the longitudinal direction than the terminating position B, the dimensions of the slit 13 varying in response to changes in the force applied to the structural member;

[0045] Multiple optical fibers 2 are operably connected to the structural member.

[0046] In the depicted embodiments, the structural member includes a hollow tube. The structural member may comprise a hollow cylindrical tube, or may be manufactured from other shapes besides a hollow cylindrical tube, including but not limited to tubes or rods with square, rectangular, or cross-shaped cross sections. The material of the structural member is not limited and may include metallic materials such as titanium or platinum / iridium, or non-metallic materials such as polymers or ceramics. The material used for the structural member can be selected to mitigate the effects of thermal expansion. The structural member may be made of materials with a low coefficient of thermal expansion, such as fused silica, alumina such as bauxite (Al2O3), liquid crystal polymers, etc., or of metal / ceramic composite materials, such as nickel-iron alloys designed for a low coefficient of thermal expansion relative to metals, to reduce the effect of temperature on the force sensor. The non-limiting dimensions of the structural member are approximately 1 to 8 mm in length and approximately 1.5 to 3 mm in diameter.

[0047] In one embodiment, the rotational interval between the starting position A and the ending position B of the slit 13 about the longitudinal axis 10 is greater than 180°. The larger the rotational interval between the starting position A and the ending position B, the higher the sensitivity of the force sensor. The slit 13 can extend from the starting position A to the ending position B by rotating 360° or more about the longitudinal axis 10.

[0048] In the depicted embodiment, the slit includes a spiral shape. The shape of the slit 13 is not limited; the slit can extend from the starting position A to the ending position B in an arc, straight line, or zigzag shape, etc. The pitch of the spiral slit is not limited; the pitch can be the same or different in different sections of the slit 13. The sensitivity of the force sensor can be adjusted by adjusting the pitch of the spiral slit. The smaller the pitch, the greater the flexibility of the structural member and the higher the sensitivity of the force sensor. The pitch is defined as the distance along the longitudinal axis between the starting position A and the ending position B when the slit rotates 360° around the longitudinal axis.

[0049] In one embodiment, the distance between the starting position A and the ending position B along the longitudinal axis is between 0.5 and 1.5 mm. When the distance between the starting position A and the ending position B along the longitudinal axis is constant, the sensitivity of the force sensor can be adjusted by changing the number of rotations of the slit around the longitudinal axis. Increasing the number of rotations of the slit increases the flexibility of the structural member, thereby improving the sensitivity of the force sensor; that is, the smaller the pitch, the greater the flexibility of the structural member, and the greater the sensitivity of the force sensor.

[0050] The size of the slit 13 can be 0.15-0.3 mm, and is defined as the distance along the longitudinal axis between the distal surface 111 of the proximal end 11 and the proximal surface 121 of the distal end 12. A larger slit size results in higher sensitivity of the force sensor. The slit 13 can be formed using various methods available to technicians, such as, but not limited to, laser processing, wire EDM, and electrical discharge machining.

[0051] In the depicted embodiment, the pipe wall portion of the structural member with approximately sides AC, CB, BD, and DA forms a connecting portion 15, wherein AC is approximately parallel to the longitudinal axis 10, BD is approximately parallel to the longitudinal axis 10, the surface containing the arcuate segment of CB is approximately perpendicular to the longitudinal axis 10, and the surface containing the arcuate segment of DA is approximately perpendicular to the longitudinal axis. When a force is applied to the structural member, the structural member deforms, and the distal end 12 moves closer to or further away from the proximal end 11 about the connecting portion 15 as an axis, causing a change in the size of the slit 13.

[0052] The structural member has orthogonal axes on a cross-section perpendicular to the longitudinal axis. The yy axis indicates the direction in which the structural member is most sensitive to lateral forces, and the xx axis indicates the direction in which the structural member is least sensitive to lateral forces. In the structural member of this embodiment, the midpoint of the rotation interval between the starting position A and the ending position B around the longitudinal axis is taken as point Z, that is, the rotation interval angle between point Z and points A and B is equal. The intersection of the longitudinal axis and the cross-section is taken as point O, and the connection between point O and point Z is the yy axis. The xx axis passes through the longitudinal axis.

[0053] Optical fiber 2 can be arranged on the structural component. The number of optical fiber 2 can be three or more, and they are rotated and spaced apart around the longitudinal axis 10. The rotational interval angle between the optical fibers can be between 30° and 180°.

[0054] In one embodiment, two of the three optical fibers are rotated apart by approximately equal angles with respect to the x-axis. This arrangement reduces the sensitivity differences among the different optical fibers, thereby improving the sensitivity of the force sensor. Preferably, the angle between the optical fibers and the x-axis or y-axis is 30°-60°. Preferably, two of the three optical fibers are rotated apart by approximately equal angles with respect to the y-axis.

[0055] In response to the contact force applied to the end of the structural member, the structural member deforms, causing a change in the slit size. The transmitted radiation is transmitted through the optical fiber, and the characteristics of the reflected radiation returned through the optical fiber change in response to the change in the slit size. The characteristics of the reflected radiation returned through the optical fiber include the frequency of the interference pattern, the intensity of the reflected radiation, or the center wavelength of the fiber Bragg grating integrated with the optical fiber.

[0056] In one embodiment, each of the plurality of optical fibers includes an optical fiber end 21, which terminates in proximity to a slit 13 and is oriented to emit light to a distal end 12 or a reflective member 4 disposed on the distal end 12 and to collect light reflected from the distal end 12 or the reflective member 4. The optical fiber end 21 terminating in proximity to the slit 13 is defined as the optical fiber end 21 being close to the distal surface 111 of the proximal end 11, for example, the optical fiber end 21 being substantially flush with, slightly recessed from, or slightly protruding from the distal surface 111.

[0057] A gap 3 is formed between the optical fiber end 21 and the distal end 12, or between the reflective member 4 disposed at the distal end 12. The gap 3 can be characterized as having an operating length that varies in response to changes in the size of the slit 13. The operating length of the gap 3 determines the characteristics of the reflected radiation returned through the optical fiber 2, i.e., the frequency of the interference pattern or the intensity of the reflected radiation. The gap 3 can be, for example, an interference-type gap or an intensity-varying gap. The interference-type gap used herein is a gap having properties such as those observed in Michelson interferometers or Fabry-Perot resonators. An intensity-varying gap is a gap configured to capture a reflected intensity that varies inversely with the operating length of the gap 3. In response to a contact force applied to the end of the structural member, deformation of the structural member causes a change in the size of the slit, and the operating length of the gap 3 varies with the change in the slit size in response to the contact force.

[0058] A gap 3 may be formed between the optical fiber end 21 and the proximal surface 121 of the distal end 12. The operating length of the gap 3 is the distance between the optical fiber end 21 and the proximal surface 121 of the distal end 12 and may be different from the size of the slit 13. The proximal surface 121 of the distal end 12 may be formed perpendicular to the longitudinal axis 10 in the position opposite to the optical fiber end 21.

[0059] The structural member may include a plurality of grooves 14 formed on its outer surface. The grooves 14 may be rotatably spaced about a longitudinal axis 10 and may be oriented in a generally axial direction along the structural member, the spacing angle between the grooves 14 being determined according to the spacing angle of the optical fibers 2. The grooves 14 may extend along the proximal end 11 of the structural member and terminate at a slit 13. The optical fibers 2 are placed in the grooves 14 and may be adhered thereto by an adhesive or bonding material such that the optical fiber ends 21 terminate at adjacent slits 13, for example by epoxy potting compound, or alternatively, may be press-fitted or otherwise fastened to the structural member. With the above arrangement, the optical fibers 2 face the proximal surface 121 of the distal end 12. The proximal surface 121 defines the boundary of the gap 3 opposite to the optical fiber ends 21. The proximal surface 121 may be made highly reflective. The reflective surface may be made by polishing the metal structural member or by depositing a reflective material onto the metal or non-metal structural member.

[0060] In one embodiment, the force sensor further includes a reflective member 4, which may be disposed in a groove in the distal end 12 and adhered thereto by an adhesive or bonding material such that the reflective member end 41 terminates at an adjacent slit 13, the reflective member end 41 being aligned with the optical fiber end 21 to form a gap 3. The termination of the reflective member end 41 at the adjacent slit 13 is defined as the reflective member end 41 terminating near the proximal surface 121 of the distal end 12; for example, the optical fiber end 21 may be substantially flush with, slightly recessed from, or slightly protruding from the proximal surface 121. The operating length of the gap 3 is the distance between the optical fiber end 21 and the reflective member end 41. The reflective member may also be integrally formed with a structural member. The surface of the reflective member end 41 may be made highly reflective.

[0061] The material of the reflective component 4 is not limited. It can be an optical fiber with a high coefficient of thermal expansion, including but not limited to titanium, aluminum-doped optical fiber, sapphire optical fiber, etc. The reflective component with the same coefficient of thermal expansion as the structural component can be selected to offset the effect of thermal expansion or contraction. The material of the reflective component 4 can have a sufficient reflectivity to eliminate the need for a coating, or the end 41 of the reflective component can be polished to provide a fully reflective surface, and / or it can still be coated.

[0062] The optical fiber end 21 can be made partially reflective to establish the Fabry-Perot effect. When the transmitted radiation is transmitted through the optical fiber 2 into the gap 3, the interaction between the proximal surface 121 of the distal end 12 or the reflective member end 41 and the partially reflective optical fiber end 21 produces mutual reflections therebetween, thereby forming an interference pattern with a frequency dependent on the operating length of the interference gap. A portion of the radiation entering the gap 3 returns as reflected radiation to the optical fiber 2, which defines the modulated waveform generated by, for example, the principle of multiple mutual reflections of a Fabry-Perot resonator.

[0063] The optical fiber tip 21 may be treated with an anti-reflective coating. This arrangement can enhance or optimize the intensity of reflected light returning via optical fiber 2, the intensity of which can vary with the operating length of gap 3, from which the size of the operating length of gap 3 can be inferred. Transmitted radiation enters the intensity-changing gap through optical fiber 2, and a portion of the transmitted radiation is reflected back into optical fiber 2. The intensity of the reflected radiation received by optical fiber 2 varies inversely with the size of the intensity-changing gap.

[0064] In one embodiment, the optical fiber 2 can be an optical fiber with a fiber Bragg grating sensor. The fiber Bragg grating sensor is integrated with the optical fiber 2 and reflects only a portion of the transmitted radiation near the center wavelength, the center wavelength of which is reflected depending on the spacing between the gratings of the fiber Bragg grating. In this embodiment, the optical fiber 2 can be arranged on the inner surface of the structural member. Therefore, the structural member does not need to include a groove extending axially on the outer surface. The optical fiber 2 can be fixed to the inner surface using an adhesive material. The optical fiber 2 is aligned along the length of the structural member such that the fiber Bragg grating sensor is fixedly bridged to the proximal end 11 and the distal end 12. The adhesive material may include glue or epoxy resin. The adhesive material can be selected to closely match the coefficient of thermal expansion (CTE) of the structural member and / or the optical fiber 2, or to provide a CTE between the CTEs of the structural member and the optical fiber 2 to provide a transition therebetween.

[0065] The deformation of the structural members in response to axial and lateral forces is analyzed below. When an axial force is applied to the structural member, the connecting part 15 bends around the x-axis, and the distal end 12 moves closer to the proximal end 11 with the connecting part as the axis, causing the size of the slit 13 to decrease, which in turn leads to a decrease in the operating size of the gap 3.

[0066] Figure 9 The deformation of the force sensor under force is shown. The deformation of the force sensor under force in this embodiment is similar to... Figure 9The stress deformation of the embodiments shown is roughly the same. When subjected to a transverse force from the x-axis direction, due to the distance between the starting position A and the ending position B of the slit 13 along the longitudinal axis 10, the size of the slit near the starting position A increases, and the size of the slit near the ending position B decreases; that is, taking the surface formed by the y-axis and the longitudinal axis as the interface, the size of the slit on one side of the interface where the force is applied increases, and correspondingly, the operating size of the gap 3 on one side of the interface also increases, while the size of the slit on the other side of the interface decreases, and correspondingly, the operating size of the gap 3 on the other side also decreases.

[0067] When subjected to a lateral force from the yy axis, the connecting part 15 bends around the xx axis, thereby reducing the size of the slit 13, which in turn reduces the operating size of the gap 3.

[0068] In three-dimensional space, a combined force vector with axial and lateral components is described by superposition. Therefore, by calibrating the response of the force sensor under these pure load conditions and superimposing various responses to infer the axial and lateral components, the force vector in three-dimensional space can be determined.

[0069] In this embodiment, the slit extends from a starting position A on the side of the structural member, rotating around the longitudinal axis 10, to a ending position B on the side of the structural member. The starting position A is closer to the proximal end 11 in the longitudinal axis direction than the ending position B, thereby improving the sensitivity to lateral forces in the x-axis direction. This ensures that the ratio of the sensor's sensitivity to lateral forces in the y-axis direction to its sensitivity to lateral forces in the x-axis direction is within three times, thus improving the overall accuracy of the sensor. Simultaneously, it allows for a further reduction in the length and volume of the force sensor, which is more conducive to the integration of the force sensor and the conduit.

[0070] Figures 7 to 8 A schematic diagram of a force sensor according to one embodiment is shown. In this embodiment, the slit extends from a starting position A, approximately 360° around the longitudinal axis, to an ending position B. The line AB connecting the starting position A and the ending position B is approximately parallel to the longitudinal axis 10.

[0071] Figure 9 The diagram illustrates the deformation of a structural member under a lateral force along the x-axis. The solid lines represent the deformed outline, while the dashed lines represent the original outline. Since AB is approximately parallel to the longitudinal axis 10, the structural member deforms more significantly under a lateral force along the x-axis. When subjected to a lateral force along the y-axis, the structural member bends around the x-axis with point A as its support, causing a reduction in the size of slit 13, which in turn reduces the operating size of gap 3.

[0072] This disclosure provides a method for manufacturing a force sensor, including:

[0073] A structural member defining a longitudinal axis is provided, the structural member including a proximal end and a distal end, the structural member extending from the proximal end along the longitudinal axis towards the distal end;

[0074] A slit is formed between the proximal end and the distal end, the slit extending about the longitudinal axis from a starting position on the side of the structural member to a terminating position on the side of the structural member, the starting position being closer to the proximal end in the longitudinal axis direction than the terminating position, and the size of the slit changing in response to changes in the force applied to the structural member;

[0075] Multiple optical fibers are operatively connected to the structural member.

[0076] In one embodiment, a force-sensing catheter includes: a flexible elongated body having a distal end; and a force sensor according to any of the preceding embodiments, the force sensor being disposed within the flexible elongated body near the distal end. The force sensor compresses or bends in response to a contact force applied to the distal end of the flexible elongated body, for example, when the distal end contacts the wall of a blood vessel or organ.

[0077] Force-sensing catheters can be of a size and length suitable for insertion into human blood vessels or organs. A force-sensing catheter includes a proximal portion, a middle portion, and a distal portion, the distal portion of which may include an end actuator housing a force sensor. Depending on the application, a force-sensing catheter can be a hollow structure (i.e., having a lumen) or a non-hollow structure (i.e., without a lumen).

[0078] The end effector may include, but is not limited to, mapping or ablation electrodes, such as the various types of mapping or ablation electrodes used in the art for the diagnosis or treatment of blood vessels or organs. The force-sensing catheter may be configured as an electrophysiological catheter to perform cardiac mapping and ablation. In other embodiments, the force-sensing catheter may be configured to deliver drugs or bioactive agents to the wall of a blood vessel or organ, or to perform minimally invasive procedures such as transmyocardial revascularization or cryoablation.

[0079] The force-sensing catheter disclosed herein can provide feedback on the force applied by the catheter to the tissue walls at the treatment site, thereby improving the sensitivity and accuracy of force sensing.

[0080] Furthermore, the technical features disclosed above are not limited to the combinations of the disclosed features with other features. Those skilled in the art can also make other combinations of the technical features according to the purpose of the disclosure in order to achieve the purpose of this disclosure.

Claims

1. A force sensor, characterized in that, include: A structural member defining a longitudinal axis, the structural member including a proximal end and a distal end, the structural member extending from the proximal end along the longitudinal axis toward the distal end; A slit is defined between the proximal end and the distal end, the slit extending about the longitudinal axis from a starting position on the side of the structural member to a terminating position on the side of the structural member, the starting position being closer to the proximal end in the longitudinal axis direction than the terminating position, such that the ratio of the force sensor's sensitivity to lateral forces in the direction of maximum sensitivity to lateral forces in the direction of minimum sensitivity is within 3 times; the size of the slit changes in response to changes in the force applied to the structural member; Multiple optical fibers operatively connected to the structural member.

2. The force sensor according to claim 1, characterized in that, The rotational interval between the starting position and the ending position about the longitudinal axis is greater than 180°.

3. The force sensor according to claim 1, characterized in that, The distance between the starting position and the ending position along the longitudinal axis is 0.5mm-1.5mm.

4. The force sensor according to claim 1, characterized in that, The slit has a size of 0.1mm-0.3mm, and the slit size is the distance between the distal surface of the proximal end and the proximal surface of the distal end along the longitudinal axis.

5. The force sensor according to claim 1, characterized in that, The slit includes a spiral slit.

6. The force sensor according to claim 1, characterized in that, The structural components include hollow tubes.

7. The force sensor according to claim 1, characterized in that, Each of the plurality of optical fibers includes an optical fiber end, and a gap is formed between the optical fiber end and the distal end or a reflective member disposed at the distal end, the operating size of the gap changing in response to a change in the size of the slit.

8. The force sensor according to claim 1, characterized in that, Each of the plurality of optical fibers includes an integrated fiber Bragg grating sensor.

9. A force-sensing catheter, comprising: A flexible, slender body with a distal end; and The force sensor according to any one of claims 1-8 is disposed near the distal end within the flexible elongated body.

10. A method for manufacturing a force sensor, characterized in that, include: A structural member defining a longitudinal axis is provided, the structural member including a proximal end and a distal end, the structural member extending from the proximal end along the longitudinal axis toward the distal end; A slit is formed between the proximal end and the distal end, the slit extending about the longitudinal axis from a starting position on the side of the structural member to a terminating position on the side of the structural member, the starting position being closer to the proximal end in the longitudinal axis direction than the terminating position, and the size of the slit changing in response to changes in the force applied to the structural member; Multiple optical fibers are operatively connected to the structural member.

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