Fbg type wearable fingertip three-dimensional force sensor and three-dimensional force measurement method for traditional chinese medicine

Abstract

The application discloses a FBG type wearable fingertip three-dimensional force sensor for traditional Chinese medicine and a three-dimensional force measuring method, and the sensor comprises a fingertip, an elastic body, a fixed finger sleeve and a plurality of optical fibers; the fingertip is a force collector of the FBG type wearable fingertip three-dimensional force sensor for traditional Chinese medicine; the first end of the elastic body is connected with the fingertip, receives the force transmitted by the fingertip and generates deformation; the second end of the elastic body is connected with the fixed finger sleeve and is used for wearing on a finger; the plurality of optical fibers are uniformly arranged on the elastic body and generate deformation in X, Y and Z directions under the deformation of the elastic body, so that the three-dimensional force of the fingertip is obtained. The sensor adopts the FBG, no current passes through the optical fiber, and no electrical connection is needed; the force sensing system is not disturbed by electric noise and electromagnetic interference; the sensing element has small size and light weight, high precision, zero drift, wide frequency response and good high-temperature performance.

Description

Technical Field

[0001] This invention relates to the field of force sensor technology, and in particular to an FBG-type wearable fingertip three-dimensional force sensor for traditional Chinese medicine and a three-dimensional force measurement method. Background Technology

[0002] The development of Traditional Chinese Medicine (TCM) techniques can be traced back thousands of years to ancient China. In ancient times, TCM was a primary medical practice, serving as a main means of treating and preventing various diseases. Over time, TCM techniques have continuously developed and improved. During the Han Dynasty, Zhang Zhongjing's *Treatise on Febrile and Miscellaneous Diseases* and *Essential Prescriptions of the Golden Chamber* became classic works of TCM, profoundly influencing its development. With advancements in science and technology and the continuous accumulation of medical knowledge, TCM techniques have been constantly improved and perfected. Currently, TCM techniques have developed into a complete discipline, encompassing various treatment methods such as herbal medicine, acupuncture, massage, and Qigong. TCM techniques are widely used in the treatment of chronic diseases, rehabilitation therapy, and pain management, and have received increasing attention and recognition. With the global recognition and promotion of TCM, the development of TCM techniques will receive even greater emphasis and attention.

[0003] Traditional Chinese medicine (TCM) uses palpation and massage to assess the body's condition and provide treatment. However, the results of manual palpation and massage are often influenced by the doctor's subjectivity and are not entirely objective. Force sensors can help TCM doctors measure and record the pressure and force distribution on the body's surface, thus providing a more objective assessment of the patient's physical condition.

[0004] In traditional Chinese massage therapy, force sensors help practitioners measure the strength and depth of techniques more accurately to ensure treatment effectiveness. By recording the strength and depth of the techniques in real time, doctors can adjust the treatment methods promptly to minimize patient discomfort.

[0005] Force sensors can also be used for the training and skills assessment of traditional Chinese medicine (TCM) doctors. By analyzing the force and depth of different doctors' techniques, doctors can understand their skill gaps and make improvements. Furthermore, force sensors can assess the skill level of TCM doctors in massage therapy and help train doctors to better master these skills. Measuring force can also play a role in acupuncture, cupping, and other treatments. By measuring the contact force during acupuncture and cupping, doctors can help master the force and depth during treatment, improving therapeutic effects.

[0006] The application of force sensors in traditional Chinese medicine is of great significance. It can help TCM doctors to more accurately assess patients' physical condition, improve treatment effectiveness and skill level, and thus better serve patients.

[0007] Currently, there is limited research on force sensors in the field of traditional Chinese medicine, and the research faces many problems and challenges. For example, in practical applications, TCM diagnosis is usually conducted in a clinical environment where environmental changes are complex, and factors such as temperature, humidity, and noise may affect the test results. At the same time, there are also some practical problems, such as the large size of the sensor, limited accuracy, and severe coupling. Summary of the Invention

[0008] This invention provides an FBG-type wearable fingertip three-dimensional force sensor for traditional Chinese medicine and a three-dimensional force measurement method, which has good environmental performance.

[0009] To achieve the above technical objectives, the present invention adopts the following technical solution:

[0010] An FBG-type wearable three-dimensional force sensor for TCM fingertips includes a fingertip, an elastomer, a fixed finger sleeve, and multiple optical fibers;

[0011] The fingertip is an FBG-type wearable three-dimensional force sensor for traditional Chinese medicine, which is used to collect force data.

[0012] The first end of the elastomer is connected to the fingertip, receiving the force transmitted by the fingertip and deforming accordingly.

[0013] The fixed finger sleeve is connected to the second end of the elastomer and is used for wearing on the finger;

[0014] The multiple optical fibers are uniformly arranged on the elastic body, and under the deformation of the elastic body, they generate deformation in the X, Y, and Z directions, resulting in the three-dimensional force on the fingertip.

[0015] Furthermore, the fingertip is hemispherical, and the hemispherical surface extends to form a hollow cylinder, which serves as a protective shell for the fingertip; the first end of the elastomer is provided with an external cylindrical thread, which is rotatably connected to the internal thread of a small hole provided inside the hemispherical fingertip inside the protective shell.

[0016] Furthermore, the first end of the elastic body is a helical spring, the middle section is a hollow cylinder, and the second end is a circular base plate;

[0017] The top of the helical spring is connected to the fingertip, and the circular base plate is connected to the fixed finger sleeve;

[0018] An optical fiber passes through a circular hole on the central axis of the hollow cylinder in the middle section and is fixed in a suspended and taut state between the top of the helical spring and the circular base plate, and is led out from the small hole in the center of the circular base plate.

[0019] In addition, four optical fibers of equal length are arranged parallel to each other and evenly along the axis of the hollow cylinder. Each optical fiber is embedded and pasted into the groove of the helical spring and the circular base plate, and is in a taut and suspended state. They are led out from four small holes that are evenly distributed at 90-degree intervals along the circumference of the circular base plate.

[0020] Furthermore, on the circumferential surface of the hollow cylinder of the elastic body, there are four rows of parallel and staggered elliptical holes.

[0021] Furthermore, let the axial direction of the hollow cylinder of the elastic body be the z-direction, and the optical fiber set on the central axis of the hollow cylinder be the central optical fiber. The four optical fibers on the outer circumference of the hollow cylinder of the elastic body are fiber one, fiber two, fiber three, and fiber four in sequence along the circumference of the hollow cylinder. The central optical fiber is used to detect the force in the z-direction, fiber one and fiber three are used to detect the force in the y-direction, and fiber two and fiber four are used to detect the force in the x-direction.

[0022] Furthermore, the fixed finger cot includes a distal fixed finger cot, a proximal fixed finger cot, and a V-shaped finger cot connector. The hollow interior of the distal fixed finger cot is used to fix the fingertip, and the hollow interior of the proximal fixed finger cot is used to fix the middle section of the finger. The V-shaped finger cot is formed by a long ear plate and a short ear plate in a V-shape. Two sets of ear plates extend from the bottom surface of the second end of the elastic body. The ear plate A is screwed to the long ear plate of the V-shaped finger cot connector, and the ear plate B is riveted to the front parallel ear plate of the distal fixed finger cot. The short ear plate of the V-shaped finger cot connector is screwed to the ear plate of the proximal fixed finger cot, and the rear parallel ear plate of the distal fixed finger cot is riveted to the ear plate of the proximal fixed finger cot.

[0023] A three-dimensional force measurement method uses an FBG-type wearable fingertip three-dimensional force sensor for measurement. The sensor includes a fingertip, an elastomer, a fixed finger sleeve, and multiple optical fibers. The fingertip is the force acquisition unit of the FBG-type wearable fingertip three-dimensional force sensor. The first end of the elastomer is connected to the fingertip, receiving the force transmitted by the fingertip and deforming. The fixed finger sleeve is connected to the second end of the elastomer. The multiple optical fibers are evenly distributed on the elastomer. The three-dimensional force measurement method is as follows:

[0024] When a finger is inserted into the fixed finger sleeve, the fingertip of the sensor comes into contact with the object being measured. The fingertip of the sensor is subjected to the reaction force of the object being measured, that is, the fingertip of the sensor is subjected to force.

[0025] The elastomer receives the force transmitted from the fingertip and deforms accordingly.

[0026] The multiple optical fibers undergo X, Y, and Z deformations under the deformation of the elastic body, resulting in the three-dimensional force on the fingertip.

[0027] Furthermore, the first end of the elastic body is a helical spring, the middle section is a hollow cylinder, and the second end is a circular base plate;

[0028] The top of the helical spring is connected to the fingertip, and the circular base plate is connected to the fixed finger sleeve;

[0029] An optical fiber passes through a circular hole on the central axis of the hollow cylinder in the middle section and is fixed in a suspended and taut state between the top of the helical spring and the circular base plate, and is led out from the small hole in the center of the circular base plate.

[0030] In addition, four optical fibers of equal length are arranged parallel to and evenly distributed on the circumference of the hollow cylinder along the axial direction of the hollow cylinder, and are led out from four small holes evenly distributed at 90-degree intervals along the circumference of the circular base plate.

[0031] Furthermore, let the axial direction of the hollow cylinder of the elastic body be the z-direction, the optical fiber set on the central axis of the hollow cylinder be the central optical fiber, and the four optical fibers on the outer circumference of the hollow cylinder of the elastic body be fiber one, fiber two, fiber three, and fiber four in sequence along the circumference of the hollow cylinder; the central optical fiber is used to detect the force in the z-direction, fiber one and fiber three are used to detect the force in the y-direction, and fiber two and fiber four are used to detect the force in the x-direction;

[0032] Force in the x direction The force applied to the fingertip causes the helical spring to deform, which in turn causes the hollow cylinder to deform. The deformation is transmitted to fiber 1, fiber 2, fiber 3, and fiber 4. Fiber 2 and fiber 4 undergo deformations of equal magnitude but opposite directions, causing corresponding shifts in their center wavelengths. The central fiber, fiber 1, and fiber 3 are located on the neutral plane of the deformation in the x-direction, and their deformations are negligible compared to those of fiber 2 and fiber 4. By differentially processing the shifts in the center wavelengths of fiber 2 and fiber 4, the influence of temperature on the center wavelength shift is eliminated, and the force Fx in the x-direction can be measured.

[0033] Force in the y direction The force applied to the fingertip causes the helical spring to deform, which in turn causes the hollow cylinder to deform. The deformation is transmitted to fiber 1, fiber 2, fiber 3, and fiber 4. Fiber 1 and fiber 3 undergo deformation of equal magnitude but opposite direction, causing corresponding shifts in their center wavelengths. The central fiber, fiber 2, and fiber 4 are located on the neutral plane of the deformation in the y-direction, and their deformation is negligible relative to that of fiber 1 and fiber 3. By differentially processing the shifts in the center wavelengths of fiber 1 and fiber 3, the influence of temperature on the center wavelength shift is eliminated, and the force Fy in the y-direction can be measured.

[0034] Force in the z-direction The force applied to the fingertip causes the helical spring and the hollow cylinder to deform simultaneously. The deformation is transmitted to the central optical fiber, which then undergoes compression deformation, causing a relative drift in the center wavelength of the central optical fiber. The influence of temperature on the center wavelength drift is eliminated through calculations using multiple optical fibers, and the force Fz in the z-direction is then measured.

[0035] Furthermore, the relationship between the center wavelength drift of each optical fiber and the stress and temperature changes in each direction is as follows:

[0036]

[0037] in, The initial center wavelengths of fiber 1, fiber 2, fiber 3, fiber 4, and the central fiber are set to be equal. These refer to the center wavelength drift of fiber 1, fiber 2, fiber 3, fiber 4, and the central fiber. The elastic-optical coefficient of each optical fiber, The outer diameter of the hollow cylinder 202; The height of the helical spring 201; The height of the hollow cylinder 202; The height of the circular base plate 203; Young's modulus; Let be the moment of inertia of the cross section of the hollow cylinder 202; For temperature changes, This is the coefficient of thermal expansion of the optical fiber. The thermo-optic coefficient of the optical fiber material. The length factor of the central fiber relative to the other fibers;

[0038] By differentially processing the center wavelength shifts of fiber 1 and fiber 3, i.e. The force in the y direction was calculated. The center wavelength drift of fiber 2 and fiber 4 is differentially processed, i.e. The force in the x-direction was calculated. ; and the processing of multiple optical fibers, i.e. The force in the z-direction was calculated. .

[0039] Beneficial effects

[0040] There is a lack of wearable three-dimensional force sensors for Traditional Chinese Medicine (TCM). Existing sensors are often large, lack accuracy, and suffer from severe structural coupling, thus limiting their application in the TCM field. This invention addresses this issue by uniformly arranging multiple optical fibers on an elastomer. The deformation of the elastomer generates X, Y, and Z-direction deformations, allowing for the acquisition of three-dimensional force on the fingertip. This achieves higher sensitivity and resolution compared to existing technologies. Furthermore, the sensor utilizes FBG (fiber-optic fiber geometries), which offers excellent environmental performance. Since no current flows through the optical fibers and there are no electrical connections, the force sensing system is unaffected by electrical noise and electromagnetic interference. Its sensing element is small in size and lightweight, exhibiting high accuracy, zero drift, wide frequency response, and good high-temperature performance. Additionally, the sensor utilizes PEEK material and 3D printing technology to achieve a one-piece elastomer fabrication, resulting in excellent biocompatibility. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the overall structure of the wearable fingertip three-dimensional force sensor for traditional Chinese medicine as described in an embodiment of the present invention.

[0042] Figure 2 This is a schematic diagram of the exploded structure of the wearable fingertip three-dimensional force sensor for traditional Chinese medicine as described in an embodiment of the present invention.

[0043] Figure 3 This is a schematic diagram of the elastic body structure of the wearable fingertip three-dimensional force sensor for traditional Chinese medicine as described in an embodiment of the present invention.

[0044] Figure 4 This is a schematic diagram of the fiber optic configuration and position distribution of the wearable fingertip three-dimensional force sensor for traditional Chinese medicine as described in an embodiment of the present invention.

[0045] Figure 5 This is a force analysis diagram of the elastic body used in the wearable fingertip three-dimensional force sensor for traditional Chinese medicine, as described in an embodiment of the present invention.

[0046] Figure 6 This is the mechanical model of the elastic body Fz under the action of the wearable fingertip three-dimensional force sensor for traditional Chinese medicine as described in the embodiments of the present invention.

[0047] Figure 7 This is a schematic diagram of a wearable fingertip operation device for traditional Chinese medicine as described in an embodiment of the present invention.

[0048] The labels in the diagram are as follows: 1 is the fingertip, 2 is the elastomer, 3 is the V-shaped finger sleeve connector, 4 is the distal fixed finger sleeve, 5 is the proximal fixed finger sleeve, 6 is the screw, 7 is the rivet, 11 is the fingertip protective shell, 201 is the helical spring, 202 is the hollow cylinder, 203 is the circular base plate, 204 is the A group ear plate, 205 is the B group ear plate, 206 is fiber optic one, 207 is fiber optic two, 208 is fiber optic three, 209 is fiber optic four, 210 is the central fiber optic, 211 is the elliptical hole, 212 is the groove, 31 is the ring, 32 is the long ear plate, 33 is the short ear plate, 41 is the front parallel ear plate, 42 is the rear parallel ear plate, and 51 is the double-hole ear plate. Detailed Implementation

[0049] The embodiments of the present invention will be described in detail below. These embodiments are based on the technical solutions of the present invention and provide detailed implementation methods and specific operation processes to further explain the technical solutions of the present invention.

[0050] like Figures 1 to 4 As shown, an FBG-type wearable fingertip three-dimensional force sensor for traditional Chinese medicine includes a fingertip 1, an elastomer 2, a V-shaped finger sleeve connector 3, a distal fixed finger sleeve 4, and a proximal fixed finger sleeve 5.

[0051] The elastic body 2 is composed of a helical spring 201 and a hollow cylinder 202. The helical spring 201 has a rectangular cross-section and receives the force transmitted from the fingertip 1. The helical spring 201 transmits the force to the hollow cylinder 202. The surface of the hollow cylinder 202 has several rows of parallel and staggered elliptical holes 211. The four elliptical holes in each row are evenly distributed at 90 degrees along the circumference of the cylinder. The hollow cylinder 202 transmits the force to multiple optical fibers.

[0052] The first end of the elastomer is a helical spring, the middle section is a hollow cylinder, and the second end is a circular base plate, with the hollow cylinder fixedly connected to the circular base plate. The top of the helical spring directly contacts the fingertip, and the cross-section of the helical spring is rectangular. The diameter of the bottom surface of the helical spring is larger than the diameter of the top surface of the hollow cylinder. Several rows of parallel and staggered elliptical holes are opened on the circumference of the hollow cylinder. The hole structure consists of multiple elliptical holes evenly distributed at 90-degree intervals along the circumference of the cylinder. The circumferential surface of the elastomer is engraved with grooves, which are evenly distributed at 90-degree intervals on the outer circumference of the elastomer to facilitate the attachment of optical fibers. The hollow cylinder is fixedly connected to the circular base plate, and a small hole is opened at the center of the circular base plate to facilitate the lead-out of the central optical fiber. The central optical fiber is fixed at both ends to the small hole on the central axis of the elastomer, in a suspended and taut state. Four small holes are evenly distributed at 90-degree intervals along the edge of the circular base plate to facilitate the lead-out of optical fiber one, optical fiber two, optical fiber three, and optical fiber four.

[0053] The circular base plate has extended ear plates on its bottom surface. The ear plates are divided into group A ear plates and group B ear plates. The ear plates have holes at their ends. Group A ear plates are connected to the V-shaped finger sleeve connector by screws, and group B ear plates are connected to the distal finger sleeve by rivets. The V-shaped finger sleeve connector has a ring at its top, which is used to guide the configuration of multiple optical fibers. The V-shaped structure is composed of long ear plates and short ear plates. The ear plates have holes at their ends. The long ear plates are connected to the elastic body by rivets, and the short ear plates are connected to the proximal fixing finger sleeve. The distal fixing finger sleeve is used to fix the fingertip, and the proximal fixing finger sleeve is used to fix the middle section of the finger.

[0054] The multiple optical fibers include a central optical fiber for measuring the Z-direction force Fz of the fingertip sensor and four optical fibers for measuring the X-direction force Fx and Y-direction force Fy of the fingertip sensor, respectively.

[0055] The central optical fiber 210 is positioned on the central axis of the elastic body 1 and is used to measure the force exerted on the sensor in the Z direction. Four optical fibers are positioned on the outer circumferential surface of the elastic body 1 and are parallel to the central optical fiber 210. The four optical fibers are evenly distributed at 90-degree angles on the outer circumferential surface of the elastic body 1. Optical fibers 207 and 209 are symmetrically arranged along the X direction and are used to measure the force exerted on the sensor in the X direction. Optical fibers 206 and 208 are symmetrically arranged along the Y direction and are used to measure the force exerted on the sensor in the Y direction.

[0056] In this embodiment, all optical fibers are fiber Bragg gratings.

[0057] like Figure 2 as well as Figure 5 As shown, in the elastic body 2 described in this embodiment, the central optical fiber 210 for measuring the Z-direction force Fz of the fingertip sensor is arranged on the central axis of the elastic body 2, and is taut and suspended by fixing both ends to the holes on the central axis of the elastic body 2. Optical fibers 207 and 209 for measuring the X-direction force Fx of the fingertip sensor are symmetrically arranged along the X-direction in the groove 212 between the helical spring and the circular base plate of the elastic body 2, and are taut and suspended by attaching both ends to the groove 212 on the outer circumferential surface of the elastic body 2. Optical fibers 206 and 208 for measuring the Y-direction force Fy of the fingertip sensor are symmetrically arranged along the Y-direction in the groove 212 between the helical spring and the circular base plate of the elastic body 2, and are taut and suspended by attaching both ends to the groove 212 on the outer circumferential surface of the elastic body 2. This two-end-attached optical fiber configuration is compact and, compared with the traditional configuration method of directly attaching the optical fiber to the elastic body, can better sense the deformation from the elastic body, thereby obtaining higher sensitivity and higher resolution. It can overcome the problems of large sensor size, limited accuracy, and restricted application in the field of traditional Chinese medicine.

[0058] Furthermore, the external force Fz is transmitted to the elastic body 2, causing the helical spring 201 and the hollow cylinder 202 to deform. This deformation is transmitted to the central optical fiber 210, causing it to compress and deform, resulting in a shift in the center wavelength of the central optical fiber 210. The external force Fx is transmitted to the elastic body 2, causing the helical spring 201 to deform, which in turn is transmitted to the hollow cylinder 202, resulting in a deformation. This deformation is transmitted to the second optical fiber 207 and the fourth optical fiber 209, causing equal and opposite compression and stretching in both optical fibers, resulting in corresponding wavelength shifts in both optical fibers. The external force Fy is transmitted to the elastic body 2, causing the helical spring 201 to deform, which in turn is transmitted to the hollow cylinder 202, resulting in a deformation. This deformation is transmitted to the first optical fiber 206 and the third optical fiber 208, causing equal and opposite compression and stretching in both optical fibers, resulting in corresponding wavelength shifts in both optical fibers.

[0059] In this embodiment, the expression for the center wavelength of the fiber Bragg grating is:

[0060]

[0061] in: For axial strain, For temperature changes, This refers to the wavelength shift of the fiber Bragg grating. This is the initial center wavelength of the fiber Bragg grating; This is the coefficient of thermal expansion of the optical fiber. The thermo-optic coefficient of the optical fiber material. ε is the optical elastic coefficient of the optical fiber, which is approximately 0.22 at room temperature.

[0062] like Figure 4 As shown, when the three-dimensional force sensor is subjected to force Fx, the axial deformation of the optical fiber mainly occurs in the hollow cylinder 202. According to the principles of mechanics of materials, the axial deformation of the optical fiber 209 can be obtained as follows:

[0063]

[0064] in: This refers to the axial deformation of fiber 4209 under the action of Fx. The outer diameter of the hollow cylinder 202; The height of the helical spring 201; The height of the hollow cylinder 202; The height of the circular base plate 203; Young's modulus; Let be the moment of inertia of the cross section of the hollow cylinder 202;

[0065] Since fiber optic cable 206 and fiber optic cable 208 are located on the neutral plane of the elastic body 2 when it is bent, when Fx acts on the fingertip, the effect caused by Fx at this time is... and The magnitude of the deformation is negligible, while the axial deformation of fiber 207 is equal in magnitude but opposite in direction to the deformation of fiber 4209. Therefore, the axial deformation of fiber 2 can be expressed as:

[0066]

[0067] Similarly, when the three-dimensional force sensor is subjected to force Fy, the axial deformation of fiber optic cable 206 and fiber optic cable 208 can be expressed as:

[0068]

[0069] like Figure 5 As shown, when the three-dimensional force sensor is subjected to force Fz, the central optical fiber 210 is mainly affected by the helical spring 201 and the hollow cylinder 202. It can be seen that the axial deformation of the central optical fiber 210 is the sum of the axial deformation of the helical spring 201 and the axial deformation of the hollow cylinder 202.

[0070] According to the basic formula for the stiffness of a 201 helical spring based on the principles of mechanics of materials, we can obtain:

[0071]

[0072] in: The shear modulus of the spring material; Let be the polar moment of inertia of the spring section; The mean diameter of the spring; This represents the effective number of coils of the spring.

[0073] According to the principles of mechanics of materials, the axial deformation of the helical spring 201 is:

[0074]

[0075] refer to Figure 6 As shown, since the hollow cylinder 202 is composed of ellipses of uniform size, the four elliptical holes in the dashed section of the figure are considered as one unit. The entire hollow cylinder can be regarded as four completely identical units. Therefore, the hollow cylinder 202 can be equivalent to four parallel springs, each with a stiffness of _____. According to Hooke's Law, we can obtain:

[0076]

[0077] in, This refers to the axial deformation of the hollow cylinder 202;

[0078] Therefore, based on the above derivation, the overall axial deformation of the central optical fiber 210 can be obtained as follows:

[0079]

[0080] Since multiple optical fibers undergo linear deformation under three-dimensional force, the relationship between the center drift of the multiple optical fibers and the changes in three-dimensional force and temperature can be expressed as:

[0081]

[0082] Among them, the initial center wavelengths of multiple optical fibers are equal, that is... Since the length of the central fiber 210 varies, the coefficient of the central fiber is expressed as follows: , It is a constant;

[0083] From the above derivation, it can be seen that multiple optical fibers will experience corresponding wavelength shifts under the influence of three-dimensional force and temperature. By performing differential calculations on the wavelength shifts, temperature self-compensation can be achieved, eliminating the influence of temperature deformation on the wavelength. Used for measuring force , Used for measurement , Used for measurement ,in It is a constant.

[0084] Example 1: The Twelve Well Points Exercise in Traditional Chinese Medicine not only has the effect of protecting and strengthening the brain and improving intelligence, but also helps with common chronic diseases in daily life. This exercise requires two fingers: the thumb and index finger simultaneously pinch the sides of the nail root of the other finger. The two fingers applying the force are equipped with three-dimensional force sensors at their fingertips. Figure 7 As shown. During the acupressure technique, the three-dimensional force sensor worn on the finger can detect the applied three-dimensional forces Fx, Fy, and Fz, thereby achieving the best results.

[0085] Each FBG-type TCM wearable fingertip three-dimensional force sensor utilizes an elastomer 2, which consists of a helical spring 201, a hollow cylinder 202, a circular base plate 203, and multiple optical fibers. It is used to measure the forces Fx, Fy, and Fz. Specifically, the central optical fiber 210 is used to measure the force Fz in the Z direction, the second optical fiber 207 and the fourth optical fiber 209 are used to measure the force Fx in the X direction, and the first optical fiber 206 and the third optical fiber 208 are used to measure the force Fy in the Y direction.

[0086] Specifically, when the three-dimensional force sensor is subjected to force, the external force acts on the fingertip 1, and the fingertip 1 transmits the force to the elastic body 2, causing the elastic body 2 to deform. The elastic body 2 then transmits the deformation to multiple optical fibers. When the force Fx in the X direction acts on the fingertip 1, the force is transmitted to the elastic body 2, and the helical spring 201 of the elastic body 2 deforms, transmitting the deformation to the hollow cylinder 202. This causes the center wavelengths of optical fibers 207 and 209 to drift by equal magnitude but opposite direction. Since optical fibers 206, 208, and the central optical fiber 210 are located on the bending neutral surface, the deformation of optical fibers 206, 208, and 210 can be ignored. Temperature compensation is achieved by using the difference in wavelength drift between optical fibers 207 and 209, while simultaneously measuring Fx. Similarly, when the force Fy in the Y direction acts on the fingertip 1, Fy is measured by using the difference in wavelength drift between optical fibers 206 and 208. When the Z-direction force Fz acts on the fingertip 1, the force is transmitted to the elastic body 2. The helical spring 201 and the hollow cylinder 202 in the elastic body 2 undergo axial deformation. The two ends of the central optical fiber 201 are fixedly attached to the central axis of the elastic body 2 and are in a taut and suspended state. Therefore, the deformation is transmitted to the central optical fiber 201, causing the central optical fiber 201 to undergo wavelength drift. Based on the above derivation formula, Fz is calculated and measured with optical fiber 1 206 and optical fiber 3 208.

[0087] The above embodiments are preferred embodiments of this application. Those skilled in the art can make various changes or improvements based on them. Without departing from the overall concept of this application, these changes or improvements should fall within the scope of protection claimed in this application.

Claims

1. An FBG-type wearable fingertip three-dimensional force sensor for traditional Chinese medicine, characterized in that, Includes fingertips, elastomers, fixed finger sleeves, and multiple optical fibers; The fingertip is an FBG-type wearable three-dimensional force sensor for traditional Chinese medicine, which is used to collect force data. The first end of the elastomer is connected to the fingertip, receiving the force transmitted by the fingertip and deforming accordingly. The fixed finger sleeve is connected to the second end of the elastic body and is used for wearing on the finger; The multiple optical fibers are uniformly arranged on the elastic body, and under the deformation of the elastic body, they generate deformation in the X, Y, and Z directions, resulting in the three-dimensional force on the fingertip. The first end of the elastic body is a helical spring, the middle section is a hollow cylinder, and the second end is a circular base plate; The top of the helical spring is connected to the fingertip, and the circular base plate is connected to the fixed finger sleeve; An optical fiber passes through a circular hole on the central axis of the hollow cylinder in the middle section and is fixed in a suspended and taut state between the top of the helical spring and the circular base plate, and is led out from the small hole in the center of the circular base plate. In addition, four optical fibers of equal length are arranged parallel and evenly along the axis of the hollow cylinder. Each optical fiber is embedded and pasted into the groove of the helical spring and the circular base plate, and is in a taut and suspended state. They are led out from four small holes that are evenly distributed at 90-degree intervals along the circumference of the circular base plate. Let the axial direction of the hollow cylinder be the z-direction. The optical fiber set on the central axis of the hollow cylinder is the central optical fiber. The four optical fibers on the outer circumference of the hollow cylinder are fiber one, fiber two, fiber three, and fiber four in sequence along the circumference of the hollow cylinder. The central optical fiber is used to detect the force in the z-direction, fiber one and fiber three are used to detect the force in the y-direction, and fiber two and fiber four are used to detect the force in the x-direction.

2. The FBG-type wearable fingertip three-dimensional force sensor for traditional Chinese medicine according to claim 1, characterized in that, The fingertip is hemispherical, and the hemispherical surface extends to form a hollow cylinder, which serves as a protective shell for the fingertip. The first end of the elastomer is provided with an external cylindrical thread, which is rotatably connected to the internal thread of a small hole provided inside the hemispherical fingertip inside the protective shell.

3. The FBG-type wearable fingertip three-dimensional force sensor for traditional Chinese medicine according to claim 1, characterized in that, The hollow cylinder of the elastic body has four rows of parallel and staggered elliptical holes on its circumferential surface.

4. The FBG-type wearable fingertip three-dimensional force sensor for traditional Chinese medicine according to claim 1, characterized in that, The fixed finger cot includes a distal fixed finger cot, a proximal fixed finger cot, and a V-shaped finger cot connector. The hollow interior of the distal fixed finger cot is used to fix the fingertip, and the hollow interior of the proximal fixed finger cot is used to fix the middle section of the finger. The V-shaped finger cot connector is formed by a long ear plate and a short ear plate in a V shape. Two sets of ear plates are provided on the bottom surface of the second end of the elastic body. The ear plate A is screwed to the long ear plate of the V-shaped finger cot connector, the ear plate B is riveted to the front parallel ear plate of the distal fixed finger cot, the short ear plate of the V-shaped finger cot connector is screwed to the ear plate of the proximal fixed finger cot, and the rear parallel ear plate of the distal fixed finger cot is riveted to the ear plate of the proximal fixed finger cot.

5. A three-dimensional force measurement method, characterized in that, The measurement is performed using the FBG-type wearable fingertip three-dimensional force sensor for traditional Chinese medicine as described in claim 1, wherein the three-dimensional force measurement method is as follows: When a finger is inserted into the fixed finger sleeve, the fingertip of the sensor comes into contact with the object being measured. The fingertip of the sensor is subjected to the reaction force of the object being measured, that is, the fingertip of the sensor is subjected to force. The elastomer receives the force transmitted from the fingertip and deforms accordingly. The multiple optical fibers undergo X, Y, and Z deformations under the deformation of the elastic body, resulting in the three-dimensional force on the fingertip.

6. The three-dimensional force measurement method according to claim 5, characterized in that, The first end of the elastic body is a helical spring, the middle section is a hollow cylinder, and the second end is a circular base plate; The top of the helical spring is connected to the fingertip, and the circular base plate is connected to the fixed finger sleeve; An optical fiber passes through a circular hole on the central axis of the hollow cylinder in the middle section and is fixed in a suspended and taut state between the top of the helical spring and the circular base plate, and is led out from the small hole in the center of the circular base plate. In addition, four optical fibers of equal length are arranged parallel to and evenly distributed on the circumference of the hollow cylinder along the axial direction of the hollow cylinder, and are led out from four small holes evenly distributed at 90-degree intervals along the circumference of the circular base plate.

7. The three-dimensional force measurement method according to claim 5, characterized in that, Let the axial direction of the hollow cylinder be the z-direction, and the optical fiber set on the central axis of the hollow cylinder be the central optical fiber. The four optical fibers on the outer circumference of the hollow cylinder are fiber one, fiber two, fiber three, and fiber four in sequence along the circumference of the hollow cylinder. The central optical fiber is used to detect the force in the z-direction, fiber one and fiber three are used to detect the force in the y-direction, and fiber two and fiber four are used to detect the force in the x-direction. A force Fx in the x-direction acts on the fingertip, causing the helical spring to deform and thus the hollow cylinder to deform. The deformation is transmitted to fiber 1, fiber 2, fiber 3, and fiber 4. Fiber 2 and fiber 4 undergo deformations of equal magnitude but opposite directions, causing corresponding shifts in their center wavelengths. The central fiber, fiber 1, and fiber 3 are located on the neutral plane of the x-direction deformation, and their deformations are negligible compared to those of fiber 2 and fiber 4. By differentially processing the shifts in the center wavelengths of fiber 2 and fiber 4 to eliminate the influence of temperature on the center wavelength shift, the force Fx in the x-direction can be measured. A force Fy in the y-direction acts on the fingertip, causing the helical spring to deform, which in turn causes the hollow cylinder to deform. The deformation is transmitted to fiber 1, fiber 2, fiber 3, and fiber 4. Fiber 1 and fiber 3 undergo deformations of equal magnitude but opposite directions, causing corresponding shifts in their center wavelengths. The central fiber, fiber 2, and fiber 4 are located on the neutral plane of the deformation in the y-direction, and their deformations are negligible compared to those of fiber 1 and fiber 3. By differentially processing the shifts in the center wavelengths of fiber 1 and fiber 3, the influence of temperature on the center wavelength shift is eliminated, and thus the force Fy in the y-direction can be measured. A force Fz in the z-direction acts on the fingertip, causing the helical spring and the hollow cylinder to deform simultaneously. The deformation is transmitted to the central optical fiber, which then undergoes compression deformation, causing a relative drift in the center wavelength of the central optical fiber. The influence of temperature on the center wavelength drift is eliminated by processing multiple optical fibers, and the force Fz in the z-direction is then measured.

8. The three-dimensional force measurement method according to claim 7, characterized in that, The relationship between the center wavelength drift of each optical fiber and the stress and temperature changes in each direction is as follows: ； in, The initial center wavelengths of fiber 1, fiber 2, fiber 3, fiber 4, and the central fiber are set to be equal. These refer to the center wavelength drift of fiber 1, fiber 2, fiber 3, fiber 4, and the central fiber. The elastic-optical coefficient of each optical fiber, The outer diameter of the hollow cylinder 202; The height of the helical spring 201; The height of the hollow cylinder 202; The height of the circular base plate 203; Young's modulus; Let be the moment of inertia of the cross section of the hollow cylinder 202; For temperature changes, This is the coefficient of thermal expansion of the optical fiber. The thermo-optic coefficient of the optical fiber material. The length factor of the central fiber relative to the other fibers; By differentially processing the center wavelength shifts of fiber 1 and fiber 3, i.e. The force in the y direction was calculated. Differential processing is performed on the center wavelength drift of fiber 2 and fiber 4, i.e. The force in the x-direction was calculated. ; and the processing of multiple optical fibers, i.e. The force in the z-direction was calculated. .

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