A force sensor, a force sensing guidewire, and a force sensing system

Abstract

The present disclosure relates to a force sensor, a force sensing guidewire and a force sensing system. The force sensing guidewire includes a proximal end portion and a distal end portion. The distal end portion includes a tip assembly including a radiopaque spring and a tip core wire nested within the radiopaque spring. The force sensing guidewire further includes at least one force sensor including a sleeve connected to the radiopaque spring, a reflective member disposed inside the sleeve, an optical fiber passing through the proximal end portion and extending into the sleeve, the optical fiber being oppositely disposed with the reflective member, and a force sensing cavity defined by an end face of the optical fiber and an end face of the reflective member. The force sensing guidewire of the present disclosure can measure a contact force between the force sensing guidewire and a tissue wall.

Description

Technical Field

[0001] This disclosure relates to a force sensor, a force sensing guidewire, and a force sensing system. Background Technology

[0002] Force-sensing guidewires can be used for minimally invasive interventional procedures in both vascular and non-vascular cavities. One configuration of the force-sensing guidewire involves a sensor housing located between a central and a distal portion, with a pressure sensor housed within the housing. A window for sensing external pressure is also provided on the sensor housing. However, the inventors have discovered that this design cannot monitor the contact force between the force-sensing guidewire and the tissue wall, and collisions between the guidewire and the tissue wall can damage the vessel or organ wall. Summary of the Invention

[0003] Therefore, the purpose of this disclosure is to provide a force-sensing guidewire that solves the above-mentioned technical problems.

[0004] The above objective is achieved by using a force-sensing guidewire as described below.

[0005] This disclosure relates to a force-sensing guidewire, comprising a proximal portion and a distal portion, wherein the distal portion includes: The head end assembly includes a developing spring and a head end core wire nested within the developing spring; At least one force sensor includes: a sleeve connected to the developing spring; a reflective member disposed inside the sleeve; an optical fiber passing through the proximal portion and extending into the sleeve, the optical fiber being disposed opposite to the reflective member; and a force sensing cavity defined by the end face of the optical fiber and the end face of the reflective member.

[0006] In one embodiment, the force sensor is disposed between the head end assembly and the proximal portion, and the sleeve is connected to the imaging spring and the proximal portion, respectively.

[0007] In one embodiment, the reflective member and the head end core wire are integrally formed metal wires.

[0008] In one embodiment, the force sensor is disposed at the tip of the force-sensing guidewire, and the optical fiber included in the force sensor extends through the proximal portion and the imaging spring into the sheath.

[0009] In one embodiment, a second force sensor is further provided between the developing spring and the proximal portion. The second force sensor includes a second sleeve, the optical fiber, and a second force sensing cavity, which is formed by the optical fiber being disconnected at a certain distance within the second sleeve.

[0010] In one embodiment, a cylindrical connector is further included, one end of which is inserted into and fixed to the developing spring, and the other end of which is disposed between the developing spring and the sleeve.

[0011] In one embodiment, the proximal portion includes a braided tube sleeved over the optical fiber and connected to the distal portion, the braided tube being formed by spirally winding multiple braided filaments arranged in parallel and closely fitted to each other.

[0012] In one embodiment, one end of the sleeve is provided with a connector for insertion into the developing spring, the outer diameter of the connector matching the inner diameter of the developing spring.

[0013] This disclosure provides a force sensor, comprising: a sleeve; a reflective member disposed at the head end inside the sleeve; an optical fiber at least partially disposed inside the sleeve, the optical fiber being disposed opposite to the reflective member; and a force sensing cavity defined by the end face of the optical fiber and the end face of the reflective member.

[0014] This disclosure also provides a force sensing system, including: the force sensor or the force sensing guide wire described above, and an interferometric demodulation device, wherein the interferometric demodulation device is connected to the optical fiber of the force sensor, and the interferometric demodulation device includes: A light source, configured to emit light, is transmitted to the force sensor via an optical fiber included in the force sensor; A birefringent optical component is configured to receive modulated light returned from the optical fiber and interfere with the modulated light to form interference light with enhanced contrast, wherein the modulated light is formed by the interference of light emitted from the light source with the force sensor; A photodetector configured to receive the contrast-enhanced interference light and form an optical signal curve; The signal processing unit is configured to receive the optical signal curve and process it to obtain the cavity length of the force sensor.

[0015] In one embodiment, the force sensing system further includes a processor configured to determine the magnitude of the force based on a pre-calibration coefficient of the force sensor and the cavity length of the force sensor.

[0016] The present invention has the following advantages: The force-sensing guidewire of the present invention is used to sense the contact force between the distal end of the guidewire and the blood vessel wall. While maintaining the operability and torsional control of the guidewire, it can provide accurate force feedback information, reduce the risk of blood vessel damage that may occur due to the inability to sense force during robot operation, and ensure the safety and effectiveness of the surgery. Attached Figure Description

[0017] 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: Figure 1 A schematic diagram of the structure of a force sensor according to this disclosure is shown; Figure 2 A diagram showing the relationship between the cavity length and force of a force sensor according to this disclosure is provided. Figure 3 A schematic diagram of the force-sensing guidewire according to a first embodiment of the present disclosure is shown; Figure 4 An AA cross-sectional view of a force-sensing guidewire according to a first embodiment of the present disclosure is shown; Figure 5 A schematic diagram of the force-sensing guidewire according to a second embodiment of the present disclosure is shown; Figure 6 An AA cross-sectional view of a force-sensing guidewire according to a second embodiment of the present disclosure is shown; Figure 7 A schematic diagram of the force-sensing guidewire according to a third embodiment of the present disclosure is shown; Figure 8 An AA cross-sectional view of a force-sensing guidewire according to a third embodiment of the present disclosure is shown.

[0018] 1-Distant section 2-Proximal section 3-Force sensor 31-Sleeve 311-Plug-in section 32-Fiber optic cable 33-Reflective component 34-Force sensing cavity 35-Dispensing hole 36-Solder point 4-Head end assembly 41-Developing spring 42-Head end core wire 5-Connector 6-Braided tube Detailed Implementation

[0019] 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.

[0020] 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.

[0021] like Figure 1 The force sensor disclosed herein includes: a sleeve 31; a reflective member 33 disposed at the head end inside the sleeve 31, the head end of the sleeve being the position where force is applied; an optical fiber 32 at least partially disposed within the sleeve, the optical fiber being disposed opposite to the reflective member; and a force sensing cavity 34 defined by the end face of the optical fiber and the end face of the reflective member. The reflective member 33 can be fixed to the head end inside the sleeve 31 by welding. The optical fiber 32 can be fixed to the tail end of the sleeve 31 by adhesive bonding or by adhesive bonding to the sleeve wall through an adhesive dispensing hole 35 disposed on the sleeve 31. The sleeve 31 and the reflective member 33 can be made of metal materials such as stainless steel or titanium alloy. The rigid structure design of the sleeve can provide stable support for the force sensor, ensuring the stability of the force sensor's position and attitude during measurement and improving measurement accuracy.

[0022] The principle of the force sensor is that when a force is applied to the head end of the force sensor, the sleeve 31 drives the reflective component 33 to move closer to the optical fiber 32, causing the cavity length of the force sensing cavity 34 to shorten. The magnitude of the force is linearly related to the length of the cavity 34. By pre-calibrating the force sensor to obtain the pre-calibration coefficients corresponding to the force sensor, the magnitude of the force can be obtained based on the cavity length of the force sensor.

[0023] like Figure 2 The figure shows the pre-calibration data of the force sensor disclosed herein. By applying force to the force sensor using a pressure gauge, the cavity length information corresponding to different forces is recorded. The correlation coefficient is greater than 0.98, and there is a good linear relationship between the cavity length of the vertical axis and the force of the horizontal axis.

[0024] The table below shows the accuracy test data of the force sensor disclosed herein. A force is applied to the force sensor by a pressure gauge. The first row shows the magnitude of the force applied to the force sensor by the pressure gauge, the second row shows the magnitude of the force measured by the force sensor disclosed herein, and the third row shows the error. The error of the force sensor is within 5%.

[0025] Force (N) measured by a force sensor 0.48 0.97 1.51 1.94 2.56 2.91 error 3.67% 1.02% 0 0 0.79% 1.02%

[0026] The following is for reference. Figures 3 to 4 Detailed description of embodiments of the force-sensing guidewire according to this disclosure. A force-sensing guidewire includes a proximal portion 2 and a distal portion 1, the distal portion including a tip assembly 4 and a force sensor 3. The force sensor 3 is disposed between the proximal portion 2 and the tip assembly 4. The tip assembly 4 includes a developing spring 41 and a tip core wire 42 nested within the developing spring 41. The force sensor 3 includes: a sleeve 31; a reflective member 33 disposed within the sleeve; an optical fiber 32 passing through the proximal portion 2 and extending into the sleeve 31, the optical fiber 32 being disposed opposite to the reflective member 33; and a force-sensing cavity 34 defined by the end face of the optical fiber and the end face of the reflective member. The sleeve 31 is connected to the proximal portion 2 and the developing spring 11 by welding.

[0027] In one embodiment, a connector 5 is used to connect the developing spring 41 and the sleeve 31 together. Since the inner diameter of the developing spring is larger than the inner diameter of the sleeve, a direct connection between the developing spring and the sleeve would be unstable. The connector is a cylindrical structure with different outer diameters. One end has an outer diameter approximately the same as the inner diameter of the developing spring, which is inserted into and welded to the developing spring 41. The other end has an outer diameter the same as the outer diameter of the sleeve 31, and is positioned between the developing spring 41 and the sleeve 31 and welded to the sleeve 31. The inner diameter of the connector is the same as the inner diameter of the force sensor's sleeve to allow the reflective component to pass through the connector. This specifically constructed connector allows for a more compact fixation of the developing spring, and the welding of the sleeve 31 to the developing spring 41 is simple and reliable.

[0028] The reflective component 33 and the head end core wire 42 can be set separately, or the reflective component 33 and the head end core wire 42 can be set as a single metal wire such as stainless steel wire (such as nickel-titanium wire), which extends from the sleeve to the developing spring. On the one hand, it plays the role of shaping the head end core wire, and on the other hand, it forms a force sensing cavity together with the optical fiber and the sleeve as a reflective component, thereby reducing the number of parts and making the structure more compact.

[0029] An adhesive dispensing hole 35 is provided on the wall of the sleeve 31 for injecting adhesive to bond and fix the optical fiber 32 to the sleeve 31. The distance between the adhesive dispensing hole 35 and the force sensing cavity 34 can be 1mm-10mm.

[0030] The reflector 33 can be fixed to the sleeve 31 or connector 5 by welding. When used in coronary arteries, the force sensing guidewire can be set to an outer diameter of 0.36 mm and an inner diameter of 0.13-0.19 mm. The sleeve 31 can be made of metal such as stainless steel or titanium alloy, with a length of 1 mm-8 mm. The reflector 33 can be made of the same material as the sleeve 31, with a diameter of 0.15 mm and a length of 1 mm-2 mm. The rigid structure design of the sleeve 31 provides stable support for the distal end of the force sensor, ensuring the stability of the force sensor's position and attitude during measurement. The optical fiber 32 can be bonded to the sleeve 31 at the adhesive dispensing hole 35 on the sleeve.

[0031] In embodiments of this disclosure, the force-sensing guidewire can measure the force exerted by the tissue and the imaging spring on the force sensor tip, preventing damage to the tissue when the imaging spring stacks on the tissue.

[0032] The proximal portion includes a braided tube 6 and a stainless steel tube (not shown in the figure), arranged sequentially from distal to proximal. The distal end is the one closest to the body, and the proximal end is the one closest to the external manipulation. The braided tube 6 and the sleeve 31 can be connected by welding. The braided tube 6 can be formed by spirally winding multiple parallel braided filaments that are tightly fitted together. The braided filaments can be made of stainless steel, such as medical-grade 304V stainless steel. The braided tube 6 can be set to a length of 280 mm, an outer diameter of 0.36 mm, and an inner diameter of 0.13 mm to 0.19 mm. The braided tube 6 can protect the internal optical fiber from damage due to mechanical stress. The stainless steel tube is 1560 mm long, providing good pushability and torsion.

[0033] Fiber 32 can establish a signal connection with an external demodulation unit to realize the output of force sensor signals. The connector adopts an LC / PC ferrule structure to ensure low-loss transmission of optical signals.

[0034] like Figures 5 to 6 The diagram shows a structural schematic of a force-sensing guidewire according to another embodiment of the present disclosure. The difference between this embodiment and the previous embodiments is that the force sensor 3 is disposed at the tip of the force-sensing guidewire, thereby sensing the force exerted by tissue on the tip of the imaging spring. Specifically, the two ends of the imaging spring are connected to the force sensor 3 and the proximal portion 2 of the force-sensing guidewire, respectively. In this embodiment, the optical fiber of the force sensor passes through the imaging spring 41 from the proximal portion 2 and extends to the sleeve 31. In the embodiments of the present disclosure, the force-sensing guidewire can measure the force exerted by tissue on the tip of the force-sensing guidewire, thereby preventing damage to the tissue by the force-sensing guidewire.

[0035] Furthermore, no connecting parts are provided in this embodiment, such as... Figure 5As shown, one end of the sleeve 31 is provided with a connector 311 for insertion into the developing spring, and the outer diameter of the connector is smaller than the outer diameter of the sleeve. This reduces the number of parts and makes the connection more secure.

[0036] like Figures 7 to 8 The diagram shows a structural schematic of a force-sensing guidewire according to a third embodiment of the present disclosure. In this embodiment, two force sensors are respectively provided on both sides of the development spring, used to measure the force exerted by the tissue on the development spring and the force exerted by the tissue and the development spring together on the proximal portion of the force-sensing guidewire. A force-sensing cavity is formed between the development spring and the proximal portion by means of an optical fiber 32 disconnected at a certain distance within the sleeve, and the optical fibers at both ends of the force-sensing cavity are fixed to the sleeve by applying adhesive through two dispensing holes on the sleeve.

[0037] This disclosure provides a force sensing system, including: the force sensor or force sensing guide wire described above, and an interferometric demodulation device, wherein the force sensor or force sensing guide wire is connected to the interferometric demodulation device via an optical fiber 32.

[0038] The interference demodulation device includes: a light source configured to emit light and transmit it to the force sensor 3 via the optical fiber; a birefringent optical component configured to receive the modulated light returned by the force sensor 3 and interfere with the modulated light to form interference light with improved contrast, wherein the modulated light is formed by the interference of light emitted by the light source at the force sensor 3; a photodetector configured to receive the interference light with improved contrast and form an optical signal curve; and a signal processing unit configured to receive the optical signal curve and process it to obtain the cavity length of the force sensor 3.

[0039] The specific principle of the interferometric demodulation device is as follows: the force sensing cavity of the force sensor generates an interference optical signal carrying cavity length information. This optical signal is input to the interferometric demodulation device, where low-coherence demodulation technology is used to obtain the interference spectrum. This spectrum is received by a photoelectric conversion device, such as a CCD, CMOS, or PD. The cavity length information is then obtained through a data processing unit. Specifically, the horizontal axis of the interference spectrum represents the cavity length (typically 0-40 μm), and the vertical axis represents the light intensity of the interference spectrum. Based on the principle of low-coherence demodulation, the horizontal axis corresponding to the maximum peak value of the interference spectrum is the cavity length of the sensing cavity. Therefore, by reading the horizontal axis corresponding to the position of the maximum light intensity in the interference spectrum, the cavity length information of the force sensing cavity can be obtained.

[0040] The force sensing system also includes a processor configured to determine the magnitude of the force based on a pre-calibration coefficient of the force sensor and the cavity length of the force sensor.

[0041] 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-sensing guidewire, characterized in that, It includes a proximal portion and a distal portion, wherein the distal portion includes: The head end assembly includes a developing spring and a head end core wire nested within the developing spring; At least one force sensor includes: a sleeve connected to the reflective spring; a reflective member disposed inside the sleeve; an optical fiber passing through the proximal portion and extending into the sleeve, the optical fiber being disposed opposite to the reflective member; and a force sensing cavity defined by the end face of the optical fiber and the end face of the reflective member.

2. The force-sensing guidewire according to claim 1, characterized in that, The force sensor is disposed between the head end assembly and the proximal portion, and the sleeve is connected to the imaging spring and the proximal portion respectively.

3. The force-sensing guidewire according to claim 2, characterized in that, The reflective component and the head end core wire are integrally formed metal wires.

4. The force-sensing guidewire according to claim 1, characterized in that, The force sensor is disposed at the tip of the force sensing guidewire, and the optical fiber contained in the force sensor extends through the proximal portion and the imaging spring into the sheath.

5. The force-sensing guidewire according to claim 4, characterized in that, A second force sensor is also provided between the developing spring and the proximal portion. The second force sensor includes a second sleeve, the optical fiber, and a second force sensing cavity. The second force sensing cavity is formed by the optical fiber being broken at a certain distance in the second sleeve.

6. The force-sensing guidewire according to claim 1, characterized in that, It also includes a cylindrical connector, one end of which is inserted into and fixed to the developing spring, and the other end of which is disposed between the developing spring and the sleeve.

7. The force-sensing guidewire according to claim 1, characterized in that, The near-end portion includes a braided tube sleeved around the optical fiber and connected to the far-end portion, the braided tube being formed by spirally winding multiple braided filaments arranged in parallel and closely fitted to each other.

8. The force-sensing guidewire according to claim 1, characterized in that, One end of the sleeve is provided with a connector for insertion into the developing spring, and the outer diameter of the connector matches the inner diameter of the developing spring.

9. A force sensor, characterized in that, include: casing; A reflective member disposed at the head end inside the sleeve; an optical fiber at least partially disposed inside the sleeve, the optical fiber being disposed opposite to the reflective member; The force sensing cavity is defined by the end face of the optical fiber and the end face of the reflective component.

10. A force sensing system, characterized in that, include: The force sensor of claim 9 or the force sensing guidewire of any one of claims 1-8, and the interferometric demodulation device, wherein the interferometric demodulation device is connected to the optical fiber of the force sensor, and the interferometric demodulation device comprises: A light source, configured to emit light, is transmitted to the force sensor via an optical fiber included in the force sensor; A birefringent optical component is configured to receive modulated light returned from the optical fiber and interfere with the modulated light to form interference light with enhanced contrast, wherein the modulated light is formed by the interference of light emitted from the light source with the force sensor; A photodetector configured to receive the contrast-enhanced interference light and form an optical signal curve; The signal processing unit is configured to receive the optical signal curve and process it to obtain the cavity length of the force sensor.

11. The force sensing system according to claim 10, characterized in that, It also includes a processor configured to obtain the magnitude of the force based on a pre-calibration coefficient of the force sensor and the cavity length of the force sensor.

Images