Magnetic multi-needle biopsy capsule robot and control method thereof

Abstract

The present application provides a magnetic multi-needle biopsy capsule robot and its control method. The capsule robot includes a capsule shell, each end of the capsule shell is provided with an end perforation, a side perforation is provided on one side of the middle portion, and the interior of the capsule shell is divided into a left chamber, a middle chamber, and a right chamber; the middle chamber is provided with: a first biopsy needle; a first permanent magnet, the first permanent magnet is configured to drive the first biopsy needle to extend from the side perforation under the drive of an external magnetic field; a reset mechanism is configured to drive the first biopsy needle to reset; the left chamber and the right chamber are both provided with: a second biopsy needle; a second permanent magnet, the second permanent magnet is configured to drive the second biopsy needle to rotate and extend from the adjacent end perforation under the drive of an external rotating magnetic field; a spiral structure is configured to achieve the movement of the second permanent magnet along its axis when the second permanent magnet rotates about its central axis. The present application can obtain tissue samples from multiple locations in a single examination, thereby improving the comprehensiveness of the biopsy and the accuracy of the diagnosis.

Description

Technical Field

[0001] The present application relates to the field of medical device technology, and in particular to a magnetic multi-needle biopsy capsule robot and a control method thereof. Background Art

[0002] Capsule endoscopy (CE) is an advanced technology for diagnosing gastrointestinal diseases that has emerged in recent decades. However, they require active mobility and multifunctionality in terms of robotic motion to achieve widespread, untethered, and precise clinical applications. The main disadvantage of existing CE is that they only have image acquisition capabilities. However, doctors hope that CE can take on more clinical tasks, such as biopsy or drug administration. The biopsy function is an important research direction because it can effectively help doctors judge the patient's condition. In recent years, research has been focused on integrating biopsy tools such as blades, clamps, forceps, and fine needles into CE. Using blades to cut the target lesion or using forceps to tear the target tissue may cause wounds or discomfort.

[0003] In contrast, fine needle biopsy is a minimally invasive biopsy technique that has been widely used for biopsy of human organs such as the kidney, liver, thyroid, and breast. In recent years, this technology has been successfully incorporated into the design of CE biopsy modules. To actuate the biopsy tool, an actuator may be required. Common actuators include springs, motors, and permanent magnets (PMs). However, the disadvantage of using a spring actuator is that it can only be triggered once, and using a motor as an actuator poses space and energy consumption issues. Therefore, PMs are a more ideal actuation method. Permanent magnet actuators are often used in conjunction with electromagnetic actuation (EMA) systems, which can provide driving power remotely. Therefore, using a PM actuator does not consume energy from the internal battery. In addition, it occupies less space than a motor, which is very important for reducing the size of the CE.

[0004] Currently, several magnetically actuated biopsy capsule (MABC) robots for gastrointestinal diagnostics exist. These robots achieve both motion and biopsy functions under the control of an external electromagnetic drive (EMA) system. They can perform two types of active motion: planar motion and three-dimensional motion. Planar motion involves the robot rolling along the surface of the gastrointestinal tract within a rotating uniform magnetic field; three-dimensional motion involves the robot moving in three dimensions under the control of the EMA system. Upon reaching the target location, the biopsy needle can be ejected to obtain a sample and then retracted under a gradient magnetic field.

[0005] However, while these conventional endoscopes are effective in visualizing the digestive tract, they are often limited in terms of sampling location, quantity, and tissue diversity when performing biopsies. While the proposed mechanism can facilitate endoscopic examinations and biopsy procedures, it has limitations in clinical application. Due to spatial constraints, multiple biopsies in different target areas are not possible. However, the proposed mechanism can be used to perform multiple tissue biopsies at the same target site or along a section of the intestine in suspicious or abnormal cases, such as in elderly patients, who may have difficulty undergoing conventional endoscopy due to discomfort and side effects. Furthermore, the proposed capsule can easily function in tubular organs (small and large intestine), while also being able to take samples only once, allowing for single-needle biopsies. Summary of the Invention

[0006] In order to improve the problem that the existing technology is often limited by factors such as sampling location, quantity and tissue diversity when performing biopsy, and it is difficult to perform multiple biopsies in different target areas due to space limitations, the present application provides a magnetic multi-needle biopsy capsule robot and its control method.

[0007] In the first aspect, the present application provides a magnetic multi-needle biopsy capsule robot, which adopts the following technical solution:

[0008] A magnetic multi-needle biopsy capsule robot comprises a capsule shell, both ends of the capsule shell are provided with end through-holes, a side through-hole is provided on one side of the middle portion of the capsule shell, and the interior of the capsule shell is divided into a left chamber, a middle chamber, and a right chamber;

[0009] The middle chamber is provided with:

[0010] a first biopsy needle, disposed corresponding to the side perforation;

[0011] a first permanent magnet, the first biopsy needle being fixed on the first permanent magnet, the first permanent magnet being configured to drive the first biopsy needle to extend from the side puncture hole under the drive of an external magnetic field; and

[0012] a resetting mechanism, configured to drive the first biopsy needle to reposition;

[0013] The left chamber and the right chamber are both provided with:

[0014] a second biopsy needle disposed corresponding to the adjacent end perforation;

[0015] a second permanent magnet, wherein the second biopsy needle is coaxially fixed to an end of the second permanent magnet, and the second permanent magnet is configured to drive the second biopsy needle to rotate and extend from the adjacent end through-hole under the driving of an external rotating magnetic field; and

[0016] The spiral structure is configured to enable the second permanent magnet to move along its axis when the second permanent magnet rotates around its central axis.

[0017] Furthermore, the two magnetic poles of the first permanent magnet are located at both ends of its axial direction, and the two magnetic poles of the second permanent magnet are located on both sides of its central axis; in an initial state, the magnetic poles on the same side of the first permanent magnet and the second permanent magnet have the same polarity.

[0018] Furthermore, the reset mechanism includes:

[0019] Two slide rails are provided and are arranged on both sides of the first permanent magnet, and the slide rails are arranged radially along the capsule shell;

[0020] A slider is slidably mounted on the slide rail, and the first permanent magnet is fixed between the two sliders;

[0021] A return spring is sleeved on the slide rail and located between the first permanent magnet and the side through hole.

[0022] Furthermore, the spiral structure includes:

[0023] A spiral block wrapped around the outer periphery of the second permanent magnet;

[0024] A spiral groove is provided on the inner peripheral wall of the capsule shell and is adapted to the screw thread of the spiral block. Both the left chamber and the right chamber are provided with the spiral groove.

[0025] Furthermore, a baffle is fixedly connected to the inner cavity of the left chamber and the right chamber near the adjacent end perforations. The baffle is located on the side of the spiral groove away from the first permanent magnet. A through hole is formed on the baffle for the second biopsy needle to pass through.

[0026] Furthermore, the spiral directions of the spiral grooves in the left chamber and the right chamber are the same.

[0027] Furthermore, the first biopsy needle and the second biopsy needle both have an oblique tip, wherein the inner cavity of the oblique tip has barbs, and the barbs extend toward the middle of the capsule shell.

[0028] Furthermore, two partitions are fixedly connected in the capsule shell, and the two partitions divide the capsule shell into the left chamber, the middle chamber and the right chamber.

[0029] In a second aspect, the present application provides a control method for a magnetic multi-needle biopsy capsule robot, based on the above-mentioned magnetic multi-needle biopsy capsule robot, comprising the following steps:

[0030] S1. The patient swallows the capsule shell, and the capsule shell is attracted by an external magnetic field to move the capsule shell to the lesion;

[0031] S2. Based on the consistent polarity of the first permanent magnet and the two second permanent magnets on the same side, the capsule shell is fixed with a first external magnetic field;

[0032] S3. When the first biopsy needle is required to take a sample, a second external magnetic field is used to repel or attract the first permanent magnet, so that the first permanent magnet drives the first biopsy needle to extend from the side perforation, wherein the magnetic field strength of the second external magnetic field is greater than the magnetic field strength of the first external magnetic field;

[0033] S4. When the second biopsy needle is needed for sampling, an external rotating magnetic field is used to drive the corresponding second permanent magnet to rotate in the capsule shell. With the help of the spiral structure, the second permanent magnet drives the second biopsy needle thereon to extend out from the corresponding end perforation, wherein the magnetic field strength of the external rotating magnetic field is not less than the magnetic field strength of the first external magnetic field.

[0034] Furthermore, when controlling the second biopsy needle in the left chamber to take a sample, the first external magnetic field is first moved to correspond to the middle chamber and the right chamber, and then the external rotating magnetic field controls the second permanent magnet in the left chamber; the same applies when controlling the second biopsy needle in the right chamber to take a sample.

[0035] In summary, this application includes at least one of the following beneficial technical effects:

[0036] 1. By using an external electromagnetic drive system (EMA system) to output a first external magnetic field, the first permanent magnet and two second permanent magnets with the same polarity on the same side can be simultaneously attracted to stabilize the capsule shell. This can effectively avoid possible displacement, deflection, and flipping of the capsule shell during needle removal, ensuring precise alignment of the first and two second biopsy needles.

[0037] 2. When the first biopsy needle needs to be extended to take a sample, the second external magnetic field can be used to attract or repel the first permanent magnet, so that the first permanent magnet drives the first biopsy needle to move radially along the capsule shell and extend from the side perforation to take a sample. When the second biopsy needle needs to be extended to take a sample, for example, taking the second biopsy needle in the left chamber as an example, an external rotating magnetic field can be applied to the second permanent magnet in the left chamber. At this time, the second permanent magnet drives the second biopsy needle to rotate and perforate the extended end under the action of the external rotating magnetic field to take a sample. Since the magnetic field strengths of the second external magnetic field and the external rotating magnetic field are both lower than the magnetic field strength of the first external magnetic field, the withdrawal of either the first or second biopsy needle will not affect the stability of the capsule shell.

[0038] 3. The capsule robot of this application integrates multiple biopsy needles within the capsule shell, enabling the acquisition of tissue samples from multiple locations in a single examination. This improves biopsy coverage and tissue diversity, thereby enhancing the comprehensiveness of biopsies and the accuracy of diagnoses, particularly in complex or diseased areas. Furthermore, the robot utilizes magnetically driven multi-needle biopsy, allowing for remote control without the need for an internal power source, enabling precise multi-directional sampling. This technology lays the foundation for precise sampling technology for gastrointestinal diseases during clinical practice.

[0039] 4. The miniaturized design of the capsule shell allows for easy passage through complex bends and narrow areas of the digestive tract, providing a wider range of biopsy opportunities. Furthermore, this application utilizes an external electromagnetic drive (EMA) system to control the extension and movement of the biopsy needle, meaning the robot requires no internal battery power. Through the action of an external magnetic field, the movement of the corresponding permanent magnet and biopsy needle can be precisely controlled, avoiding battery drain issues and increasing the device's durability and reliability. Furthermore, this battery-free design reduces potential risks to the device's internal battery, preventing issues such as battery aging or leakage, further enhancing system safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0041] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present application;

[0042] Figure 2 It is a schematic diagram of a partial cross-sectional structure of an embodiment of the present application;

[0043] Figure 3 This is a schematic diagram of the magnetic field distribution during sampling with the first biopsy needle in the embodiment of the present application;

[0044] Figure 4 This is a schematic diagram of the magnetic field distribution during sampling with the second biopsy needle in an embodiment of the present application;

[0045] Figure 5 This is a cross-sectional view of the embodiment of the present application mainly used to show the bevel tip and barbs;

[0046] Figure 6: This is a demonstration diagram of the capsule robot of the embodiment of the present application sampling different lesion tissues; (a) the capsule robot is controlled by the first external magnetic field to approach the target tissue; (b) the second biopsy needle is controlled by the external rotating magnetic field to withdraw the needle for sampling; (c) the second biopsy needle is sampled; (d) the first biopsy needle is controlled by the second external magnetic field to withdraw the needle for sampling; (e) the first biopsy needle is sampled; (f) after the second biopsy needle is withdrawn by the external rotating magnetic field, the capsule robot is controlled by the first external magnetic field to approach the target tissue and insert the second biopsy needle for sampling; (g) the second biopsy needle is sampled.

[0047] Figure 7 : These are force analysis diagrams of the first biopsy needle during sampling in an embodiment of the present application; (a) shows the relationship between the distance between the second external magnet and the capsule robot and the force Fm exerted on the first permanent magnet; (b) shows the relationship between the displacement of the first permanent magnet and the force Fz exerted by the second permanent magnet on the first permanent magnet; (c) shows the relationship between the compression stroke of the return spring and the elastic force Fk; and (d) shows the relationship between the displacement of the first permanent magnet and the sum of the forces Fk, Fz, and Fn.

[0048] Figure 8 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. 51. 52. 53. 54. 55. 56. 57. 58. 59. 60. 61. 62. 63. 64. 65. 66.

[0049] Figure 9 This is a diagram showing the relationship between the distance between the first external magnet and the capsule robot and the forces acting on the capsule robot and the first permanent magnet in an embodiment of the present application.

[0050] Reference numerals:

[0051] 1. Capsule shell; 11. End perforation; 12. Side perforation; 13. Partition;

[0052] 21. Left chamber; 22. Middle chamber; 23. Right chamber;

[0053] 31. First biopsy needle; 32. Second biopsy needle; 331. Bevel tip; 332. Barb;

[0054] 41. First permanent magnet; 42. Second permanent magnet;

[0055] 51. Slide rail; 52. Slider; 53. Return spring; 54. Mounting seat;

[0056] 61. Spiral block; 62. Spiral groove; 63. Baffle; 631. Via hole. DETAILED DESCRIPTION

[0057] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0058] Reference Figure 1 and Figure 2 The embodiment of the present application discloses a magnetic multi-needle biopsy capsule robot, which includes a capsule shell 1, end perforations 11 are opened at both ends of the capsule shell 1, and a side perforation 12 is opened on one side of the middle portion of the capsule shell 1. The interior of the capsule shell 1 is divided into a left chamber 21, a middle chamber 22 and a right chamber 23; specifically, two partitions 13 are fixedly connected to the capsule shell 1, and the two partitions 13 separate the capsule shell 1 into a left chamber 21, a middle chamber 22 and a right chamber 23.

[0059] The middle chamber 22 is provided with:

[0060] A first biopsy needle 31 is arranged radially along the capsule shell 1 and corresponding to the side perforation 12;

[0061] a first permanent magnet 41 , on which the first biopsy needle 31 is fixed, and the first permanent magnet 41 is configured to drive the first biopsy needle 31 to extend from the side puncture 12 under the drive of an external magnetic field; and

[0062] The reset mechanism is configured to drive the first biopsy needle 31 to extend out of the side perforation 12 and then reset itself.

[0063] The left chamber 21 and the right chamber 23 are both provided with:

[0064] A second biopsy needle 32 is arranged along the axial direction of the capsule shell 1 and is corresponding to the adjacent end perforation 11;

[0065] a second permanent magnet 42 , the second biopsy needle 32 being coaxially fixed to an end of the second permanent magnet 42 , and the second permanent magnet 42 being configured to drive the second biopsy needle 32 to rotate and extend from the adjacent end through-hole 11 under the drive of an external rotating magnetic field; and

[0066] The spiral structure is configured to enable the second permanent magnet 42 to move along its axis when the second permanent magnet 42 rotates around its central axis.

[0067] Furthermore, in the specific configuration, the two magnetic poles of the first permanent magnet 41 are located at opposite ends of its axial direction, while the two magnetic poles of the second permanent magnet 42 are located on either side of its mid-axis. Specifically, the first permanent magnet 41 is an annular magnet, and the second permanent magnet 42 is a radial magnet. Initially, the magnetic poles on the same side of the first and second permanent magnets 41, 42 have the same polarity. To this end, the cylindrical second permanent magnet 42 is eccentrically positioned relative to the capsule shell 1 while maintaining parallel axis. This reduces the effect of the external rotating magnetic field on the posture of the capsule shell 1 when controlling the rotation of the first permanent magnet 41.

[0068] Therefore, when using the capsule robot of the present application, after the patient swallows the capsule shell 1, the external electromagnetic drive system (EMA system) outputs an external magnetic field, which is defined as the first external magnetic field, to synchronously adsorb the first permanent magnet 41 and the two second permanent magnets 42, and move the capsule shell 1 to the patient's lesion site. Since the first permanent magnet 41 and the two second permanent magnets 42 have the same polarity on the same side in the initial state, the strong magnetic field of the first external magnetic field can be used to strongly adsorb the three to fix the capsule shell 1 more stably, which can effectively avoid the displacement, deflection, flipping, etc. of the capsule shell 1 during the needle removal process, and can ensure the precise alignment of the first biopsy needle 31 and the two second biopsy needles 32.

[0069] When the first biopsy needle 31 needs to be extended to take a sample, the second external magnetic field can be used to attract or repel the first permanent magnet 41, so that the first permanent magnet 41 drives the first biopsy needle 31 to move radially along the capsule shell 1 and extend from the side perforation 12 to take a sample. By setting the magnetic field strength of the second external magnetic field to be greater than the magnetic field strength of the first external magnetic field, the stability of the capsule shell 1 will not be affected when the first biopsy needle 31 is extended, and the accuracy of the needle extension can be ensured. After the first biopsy needle 31 completes the sampling, the second external magnetic field is removed, and the first biopsy needle 31 is retracted into the capsule shell 1 under the action of the reset mechanism, and the next step can be carried out. The schematic diagram of the magnetic field effect can be seen in FIG. Figure 3 .

[0070] When the second biopsy needle 32 needs to be extended to take a sample, for example, taking the second biopsy needle 32 in the left chamber 21 as an example, an external rotating magnetic field can be applied to the second permanent magnet 42 in the left chamber 21. Specifically, the external magnet rotates around the axis of the capsule shell 1, and the external magnet attracts the second permanent magnet 42, so that the second permanent magnet 42 rotates in the capsule shell 1 following the external magnet; at this time, the second permanent magnet 42 has a tendency to rotate in the left chamber 21 under the action of the external rotating magnetic field, and by setting the magnetic field strength of the external rotating magnetic field to be not less than the magnetic field strength of the first external magnetic field, the capsule shell 1 does not move or rotate compared to the external electromagnetic drive system. Therefore, the second permanent magnet 42 can smoothly rotate independently in the capsule shell 1. The schematic diagram of its magnetic field effect can be seen in detail. Figure 4 Thanks to the spiral structure, when the second permanent magnet 42 rotates in the left chamber 21, it also drives the second biopsy needle 32 to move axially along the capsule shell 1. Therefore, by controlling the rotation direction of the external rotating magnetic field, the second biopsy needle 32 can be controlled to extend out of the corresponding end perforation 11 of the left chamber 21 and perform sampling. After sampling is completed, the external rotating magnetic field controls the second permanent magnet 42 to rotate in the opposite direction in the left chamber 21, causing the second biopsy needle 32 to retract into the interior of the capsule shell 1, allowing for the next step.

[0071] Among them, during specific control, the first biopsy needle 31 and the two second biopsy needles 32 can be controlled to be removed in sequence during one examination, or at the same time, or one first biopsy needle 31 and one second biopsy needle 32 can be controlled to be removed, and then the other second biopsy needle 32 can be controlled to be removed. The needle removal method can be flexibly adjusted according to actual inspection requirements.

[0072] Therefore, the capsule robot of the present application integrates multiple biopsy needles in the capsule shell 1, and can obtain tissue samples from multiple parts in a single examination, thereby improving the coverage and tissue diversity of the biopsy, thereby improving the comprehensiveness of the biopsy and the accuracy of the diagnosis, especially in complex or diseased areas, more tissue information can be obtained; and it adopts magnetically driven multi-needle biopsy, which can be remotely controlled without an internal power supply, realizing multi-directional precise sampling, laying the foundation for precise sampling technology for gastrointestinal diseases in clinical processes.

[0073] Furthermore, the miniaturized design of the capsule shell 1 allows for easy passage through complex bends or narrow areas of the digestive tract, providing a wider range of biopsy opportunities. Furthermore, this application utilizes an external electromagnetic drive (EMA) system to control the extension and movement of the biopsy needle, meaning the robot requires no internal battery power. Through the action of an external magnetic field, the movement of the corresponding permanent magnet and biopsy needle can be precisely controlled, avoiding battery drain issues and increasing the durability and reliability of the device. Furthermore, this battery-free design reduces potential risks to the device's internal battery, preventing issues such as battery aging or leakage, further enhancing system safety.

[0074] Specifically, refer to Figure 1 and Figure 2 , the above-mentioned reset mechanism includes:

[0075] Two slide rails 51 are provided and are arranged on both sides of the first permanent magnet 41. The slide rails 51 are arranged radially along the capsule shell 1.

[0076] The slider 52 is slidably mounted on the slide rail 51. The first permanent magnet 41 is fixedly connected between the two sliders 52. Specifically, a mounting seat 54 is fixedly connected between the two sliders 52. The first permanent magnet 41 is fixedly connected to the mounting seat 54. The first biopsy needle 31 also passes through the hollow portion of the first permanent magnet 41 and is fixedly connected to the mounting seat 54.

[0077] The return spring 53 is sleeved on the slide rail 51 and located between the first permanent magnet 41 and the side through hole 12 .

[0078] In this way, when the second external magnetic field is applied to the first permanent magnet 41, the first permanent magnet 41 can be moved toward the side perforation 12, so that the slider 52 slides on the slide rail 51 toward the side perforation 12. At this time, the return spring 53 is compressed and deformed; and when the second external magnetic field is removed after the sampling is completed, the elastic deformation force of the two return springs 53 drives the two sliders 52 to slide in the direction away from the side perforation 12, thereby causing the second permanent magnet 42 to drive the first biopsy needle 31 to be retracted to the inside of the capsule shell 1, thereby realizing the automatic needle retraction action of the first biopsy needle 31.

[0079] Reference Figure 1 and Figure 2 , the above-mentioned spiral structure includes:

[0080] The spiral block 61 is wrapped around the outer circumference of the second permanent magnet 42. The spiral block 61 is specifically cylindrical and has a spiral protrusion on the outside. The second permanent magnet 42 is coaxially fixed in the inner cylinder of the spiral block 61. The second biopsy needle 32 fixed to one end of the second permanent magnet 42 is arranged to pass through the end of the spiral block 61. The second biopsy needle 32 is specifically fixed to the end of the spiral block 61.

[0081] A spiral groove 62 is provided on the inner circumferential wall of the capsule shell 1 and is threadably engaged with the spiral block 61. Both the left and right chambers 21 are provided with a spiral groove 62. The spiral grooves 62 in the left and right chambers 21 have the same spiral direction, ensuring that the external rotating magnetic fields required by the second permanent magnets 42 in the left and right chambers when the needles are removed rotate in opposite directions. This prevents interference between the removal and retraction of the two second biopsy needles 32.

[0082] In addition, baffles 63 are fixedly connected to the inner cavities of the left chamber 21 and the right chamber near the adjacent end through-holes 11. The baffles 63 are located on the side of the spiral groove 62 away from the first permanent magnet 41. A through-hole 631 is formed through the baffle 63 for the second biopsy needle 32 to pass through.

[0083] Thus, when an external rotating magnetic field is applied to the second permanent magnet 42, the second permanent magnet 42, driven by the external rotating magnetic field, drives the spiral block 61 to rotate within the spiral groove 62 of the capsule shell 1, thereby achieving rotational lateral movement of the second permanent magnet 42 within the capsule shell 1, thereby achieving rotational withdrawal and retraction of the second biopsy needle 32. The baffle 63 is used to limit the minimum distance that the spiral block 61 can drive the second biopsy needle 32 toward the end perforation 11, thereby preventing the second biopsy needle 32 from being over-inserted during sampling or the spiral block 61 from being dislodged from the spiral groove 62.

[0084] Furthermore, this battery-free spiral mechanism is controlled by an external magnetic field, eliminating the need for batteries, reducing device complexity and maintenance costs. By precisely adjusting the external rotating magnetic field, the second biopsy needle 32 can be precisely controlled to locate and collect biopsy samples within the gastrointestinal tract.

[0085] In addition, refer to Figure 1 and Figure 5 In order to prevent the sample from falling off from the needle head of the first biopsy needle 31 or the second biopsy needle 32 after sampling, the first biopsy needle 31 and the second biopsy needle 32 both have an oblique tip 331, and the inner cavity of the oblique tip 331 has a barb 332, and the barb 332 extends toward the middle of the capsule shell 1.

[0086] In this way, after the first biopsy needle 31 and the second biopsy needle 32 are withdrawn for sampling, the tissue sample enters the syringe of the first biopsy needle 31 or the second biopsy needle 32 through the oblique tip 331, and the barbs 332 in the inner cavity of the oblique tip 331 can achieve a hooking effect on the tissue entering the syringe, which can effectively prevent the sample from slipping out of the syringe during the movement of the capsule shell 1 after the sampling is completed, thereby ensuring the sampling quality of the capsule robot of this application.

[0087] The present application also discloses a control method for a magnetic multi-needle biopsy capsule robot. Based on the above-mentioned magnetic multi-needle biopsy capsule robot, the following technical solution is adopted:

[0088] A magnetic multi-needle biopsy capsule robot control method, referring to Figure 1 and Figure 2 , including the following steps:

[0089] S1. The patient swallows the capsule shell 1, and the capsule shell 1 is attracted by an external magnetic field to move the capsule shell 1 to the lesion.

[0090] S2. Based on the consistent polarity of the magnetic poles of the first permanent magnet 41 and the two second permanent magnets 42 on the same side, the capsule shell 1 is fixed with a first external magnetic field.

[0091] S3. When the first biopsy needle 31 is needed to take a sample, the second external magnetic field repels or attracts the first permanent magnet 41, so that the first permanent magnet 41 drives the first biopsy needle 31 to extend from the side perforation 12 to penetrate the lesion tissue and take a sample. Figure 6 (d) and Figure 6 As shown in (e); wherein the magnetic field strength of the second external magnetic field is greater than the magnetic field strength of the first external magnetic field; after the first permanent magnet 41 completes sampling, the elastic deformation force of the two return springs 53 can realize the automatic retraction of the first biopsy needle 31.

[0092] S4. When the second biopsy needle 32 is needed to take a sample, the corresponding second permanent magnet 42 is driven to rotate in the capsule shell 1 by the external rotating magnetic field. With the help of the spiral structure, the second permanent magnet 42 drives the second biopsy needle 32 thereon to extend from the corresponding end perforation 11 to penetrate the lesion tissue and take a sample. Figure 6 Middle (a), Figure 6 (b) and Figure 6 As shown in (c); wherein the magnetic field strength of the external rotating magnetic field is not less than the magnetic field strength of the first external magnetic field.

[0093] When controlling the second biopsy needle 32 in the left chamber 21 to take a sample, the first external magnetic field is first moved to correspond to the middle chamber 22 and the right chamber, and then the external rotating magnetic field is driven to control the second permanent magnet 42 in the left chamber 21. Similarly, when controlling the second biopsy needle 32 in the right chamber to take a sample, the first external magnetic field is first moved to correspond to the middle chamber 22 and the left chamber 21, and then the external rotating magnetic field is driven to control the second permanent magnet 42 in the right chamber. Thus, by separating the first external magnetic field with a larger magnetic field strength from the external rotating magnetic field in operation, the mutual interference between the two magnetic fields can be reduced to a certain extent, while ensuring that the first external magnetic field fixes the capsule robot during the needle removal process. Furthermore, the influence of the first external magnetic field on the working second permanent magnet 42 can be reduced to a certain extent, ensuring that the external rotating magnetic field can stably and effectively drive the target second permanent magnet 42 to drive the second biopsy needle 32 to rotate and remove the needle.

[0094] Furthermore, considering the diversity of lesion sites and tissue sizes, in the actual sampling process, the second biopsy needle 32 can be first controlled to rotate out by an external rotating magnetic field, and then the capsule shell 1 can be driven to move by the first external magnetic field to insert the second biopsy needle 32 after being ejected into the lesion tissue for sampling, as shown in FIG. Figure 6 (f) and Figure 6As shown in (g), after the sampling is completed, the capsule shell 1 is moved away from the lesion tissue and the second biopsy needle 32 is controlled to rotate and retract by the external rotating magnetic field. This can provide more diverse sampling methods.

[0095] In a specific example, Figure 3 and Figure 4 As shown, a first external magnet (marked as B1) is provided to generate a first external magnetic field, a second external magnet (marked as B2) is provided to generate a second external magnetic field, and a third external magnet (marked as B3) is provided to rotate around the capsule shell 1 to generate an external rotating magnetic field, wherein the area of the second external magnet is smaller than that of the first external magnet, but the magnetic field strength thereof is greater than the magnetic field strength of the first external magnet.

[0096] When the first biopsy needle 31 needs to be removed for sampling, the second external magnet is moved closer to the capsule shell 1, so that the first permanent magnet 41 drives the first biopsy needle 31 to move 5 mm and penetrate the diseased tissue. When the first permanent magnet 41 descends 2.5 mm, the magnetic pole dividing line of the first permanent magnet 41 and the magnetic pole dividing lines of the two second permanent magnets 42 are on the same horizontal line; therefore, there are two force stages during the 5 mm movement of the first permanent magnet 41.

[0097] Phase 1: During the movement of the first permanent magnet 41 by 2.5 mm, the forces acting on it are the reaction force (Fk) of the return spring 53, the magnetic force (Fz) exerted by the two second permanent magnets 42 on the first permanent magnet 41, the resistance to penetration (Fn), and the magnetic force (Fm) exerted by the second external magnet on the first permanent magnet 41. The magnetic force exerted by the second external magnet on the first permanent magnet 41 is calculated as follows:

[0098] Fm>2Fk+Fz+Fn.

[0099] Phase 2: During the movement of the first permanent magnet 41 from 2.5 mm to 5 mm, the forces acting on it are the reaction force (Fk) of the return spring 53, the magnetic force (Fz) exerted by the two second permanent magnets 42 on the first permanent magnet 41, the resistance to penetration (Fn), and the magnetic force (Fm) exerted by the second external magnet on the first permanent magnet 41. The magnetic force exerted by the second external magnet on the first permanent magnet 41 is calculated as follows:

[0100] Fm+Fz>2Fk+Fn.

[0101] After the first biopsy needle 31 penetrates the tissue, the second external magnet is removed, and the first permanent magnet 41 moves toward the first external magnet under the action of the compressive deformation force of the return spring 53, and the first biopsy needle 31 retracts into the capsule shell 1. During this process, the first permanent magnet 41 also has two force stages during its movement.

[0102] Phase 1: During the process of the first permanent magnet 41 moving back 2.5 mm, the forces it receives are the elastic force (Fk) of the return spring 53, the magnetic force (Fz) of the two second permanent magnets 42 on the first permanent magnet 41, and the resistance (Fn) of the exit tissue. At this time:

[0103] 2Fk>Fz+Fn.

[0104] Phase 2: During the process of the first permanent magnet 41 moving back from 2.5 mm to 5 mm, the forces it receives are the elastic force (Fk) of the return spring 53, the magnetic attraction (Fz) of the two second permanent magnets 42 on the first permanent magnet 41, and the resistance (Fn) of the tissue exit. At this time:

[0105] 2Fk+Fz>Fn.

[0106] Further force analysis shows that Figure 7 (a) shows the magnitude of the force Fm on the first permanent magnet 41 when the distance between the second external magnet and the capsule shell 1 changes; Figure 7 (b) shows the magnitude of the force Fz exerted by the two second permanent magnets 42 on the first permanent magnet 41 as the first permanent magnet 41 moves (a positive value indicates that the force direction is away from the side through-hole 12, and a negative value indicates that the force direction is toward the side through-hole 12). Figure 7 In (c), the magnitude of the elastic force Fk of a single return spring 53 is shown. Figure 7 (d) shows the sum of the forces Fk, Fz, and Fn, which is 3.54 N at most. Therefore, the magnetic force exerted by the second external magnet on the first permanent magnet 41 should be greater than 3.54 N. That is, the second external magnet is within 11 mm from the capsule robot to ensure that the first biopsy needle 31 can be successfully extended and penetrate the tissue. When the second external magnet is removed, the first permanent magnet 41 is only subjected to Fk, Fz, and Fn. Figure 7 As can be seen in (d), the sum of these three forces is greater than 0 during the movement of the first permanent magnet 41 , that is, the direction of the force on the first permanent magnet 41 always tends to retract the first biopsy needle 31 . Therefore, when the second external magnet is removed, the first biopsy needle 31 can be retracted into the capsule shell 1 under the action of the reset spring 53 .

[0107] When the second biopsy needle 32 needs to be removed for sampling, using the second biopsy needle 32 on the right side of the capsule shell 1 as an example, the third external magnet is controlled to approach the right end of the capsule shell 1 and rotate clockwise around the axis of the capsule shell 1. This generates a rotating magnetic field. Under the influence of this magnetic field, the second biopsy needle 32 on the second permanent magnet 42 rotates and withdraws. The first external magnet then applies a thrust to the capsule robot, causing the extended second biopsy needle 32 to penetrate the tissue. The first external magnet then pushes the capsule robot again, forcing the second biopsy needle 32 to exit the tissue, thus ensuring the integrity of the tissue sample and avoiding unnecessary damage to surrounding tissue.

[0108] Finally, the third external magnet is controlled to be close to the right end of the capsule shell 1 and rotated counterclockwise. At this time, the change in the magnetic field will cause the second biopsy needle 32 to retract into the capsule shell 1. Figure 8 Figure (a) shows the forces acting on the capsule robot as the distance between the third external magnet and the capsule shell 1 changes. The gravitational force exerted by the third external magnet on the capsule robot must be smaller than the capsule robot's gravity, otherwise the capsule robot will be adsorbed onto the intestinal wall. The capsule robot's gravity, G, is approximately 0.072 N, so the minimum distance between the third external magnet and the capsule shell 1 is 8 cm.

[0109] Figure 8 Panel (b) shows the magnetic torque acting on the second permanent magnet 42. Experimental measurements show that the minimum magnetic torque capable of rotating the second permanent magnet 42 and the helical block 61 is 0.218 mN·m. When the third external magnet is 15 cm from the capsule robot, the magnetic torque is 0.21 mN·m, which is less than the minimum magnetic torque required for the second permanent magnet 42 to rotate. Therefore, the maximum distance between the third external magnet and the capsule shell 1 is controlled at 14 cm to ensure smooth extension of the second biopsy needle 32. Finally, it can be concluded that successful needle removal is possible when the distance between the third external magnet and the capsule shell 1 is within the range of 8 cm to 14 cm.

[0110] When the second biopsy needle 32 is extended, the first external magnet drives the capsule robot to cause the second biopsy needle 32 to penetrate the tissue. Figure 9 The figure shows the forces acting on the capsule robot and the first permanent magnet 41 as the distance between the first external magnet and the capsule shell 1 changes. It can be seen that after the second biopsy needle 32 is removed, the force on the first permanent magnet 41 is very small when the first external magnet pushes the capsule shell 1. The capsule robot weighs 0.072N, and the force exerted by the second biopsy needle 32 penetrating the tissue is 0.42N. Therefore, the force exerted by the first external magnet on the capsule robot should be greater than 0.482N. In other words, when the first external magnet is more than 20mm away from the capsule robot, it can drive the capsule robot to move and penetrate the tissue without causing the first permanent magnet 41 to move downward.

[0111] The implementation principle of a magnetic multi-needle biopsy capsule robot in the embodiment of the present application is as follows:

[0112] By means of an external electromagnetic drive system (EMA system) outputting a first external magnetic field, the first permanent magnet 41 and the two second permanent magnets 42 with the same polarity on the same side can be synchronously adsorbed to fix the capsule shell 1 more stably. This can effectively avoid the displacement, deflection, and flipping of the capsule shell 1 that may occur during the needle removal process, and can ensure the precise alignment of the first biopsy needle 31 and the two second biopsy needles 32.

[0113] When the first biopsy needle 31 needs to be extended for sampling, the first permanent magnet 41 can be attracted or repelled by the second external magnetic field, so that the first permanent magnet 41 drives the first biopsy needle 31 to move radially along the capsule shell 1 and extend from the side perforation 12 for sampling; when the second biopsy needle 32 needs to be extended for sampling, for example, taking the second biopsy needle 32 in the left chamber 21 for sampling, an external rotating magnetic field can be applied to the second permanent magnet 42 in the left chamber 21. At this time, the second permanent magnet 42 drives the second biopsy needle 32 to rotate and extend through the perforation 11 at the extended end under the action of the external rotating magnetic field to take samples; since the magnetic field strengths of the second external magnetic field and the external rotating magnetic field are both smaller than the magnetic field strength of the first external magnetic field, whether the first biopsy needle 31 or the second biopsy needle 32 is extended, it will not affect the stability of the capsule shell 1.

[0114] Moreover, the capsule robot of the present application integrates multiple biopsy needles in the capsule shell 1, which can obtain tissue samples from multiple parts in a single examination, thereby improving the coverage and tissue diversity of the biopsy, thereby improving the comprehensiveness of the biopsy and the accuracy of the diagnosis, especially in complex or diseased areas, more tissue information can be obtained; and it adopts magnetically driven multi-needle biopsy, which can be remotely controlled without an internal power supply, realizing multi-directional precise sampling, laying the foundation for precise sampling technology for gastrointestinal diseases in clinical processes.

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A magnetic multi-needle biopsy capsule robot, comprising a capsule shell, characterized in that: End perforations are provided at both ends of the capsule shell, a side perforation is provided on one side of the middle portion of the capsule shell, and the interior of the capsule shell is divided into a left chamber, a middle chamber, and a right chamber; The middle chamber is provided with: a first biopsy needle, disposed corresponding to the side perforation; a first permanent magnet, the first biopsy needle being fixed on the first permanent magnet, and the first permanent magnet being configured to drive the first biopsy needle to extend from the side puncture hole under the drive of an external magnetic field; as well as a resetting mechanism, configured to drive the first biopsy needle to reposition; The left chamber and the right chamber are both provided with: a second biopsy needle disposed corresponding to the adjacent end perforation; a second permanent magnet, wherein the second biopsy needle is coaxially fixed to an end of the second permanent magnet, and the second permanent magnet is configured to drive the second biopsy needle to rotate and extend from the adjacent end through-hole under the drive of an external rotating magnetic field; as well as The spiral structure is configured to enable the second permanent magnet to move along its axis when the second permanent magnet rotates around its central axis.

2. The magnetic multi-needle biopsy capsule robot according to claim 1, characterized in that: The two magnetic poles of the first permanent magnet are located at both ends of its axial direction, and the two magnetic poles of the second permanent magnet are located on both sides of its central axis. In an initial state, the magnetic poles on the same side of the first permanent magnet and the second permanent magnet have the same polarity.

3. The magnetic multi-needle biopsy capsule robot according to claim 1, characterized in that: The reset mechanism comprises: Two slide rails are provided and are arranged on both sides of the first permanent magnet, and the slide rails are arranged radially along the capsule shell; A slider is slidably mounted on the slide rail, and the first permanent magnet is fixed between the two sliders; A return spring is sleeved on the slide rail and located between the first permanent magnet and the side through hole.

4. The magnetic multi-needle biopsy capsule robot according to claim 1, characterized in that: The spiral structure comprises: A spiral block wrapped around the outer periphery of the second permanent magnet; A spiral groove is provided on the inner peripheral wall of the capsule shell and is adapted to the screw thread of the spiral block. Both the left chamber and the right chamber are provided with the spiral groove.

5. The magnetic multi-needle biopsy capsule robot according to claim 4, characterized in that: Baffles are fixedly connected to the inner cavities of the left chamber and the right chamber near the adjacent end perforations. The baffles are located on the side of the spiral groove away from the first permanent magnet. A through hole is formed on the baffle for the second biopsy needle to pass through.

6. The magnetic multi-needle biopsy capsule robot according to claim 4, characterized in that: The spiral directions of the spiral grooves in the left chamber and the right chamber are the same.

7. The magnetic multi-needle biopsy capsule robot according to claim 1, characterized in that: The first biopsy needle and the second biopsy needle both have an oblique tip, wherein the inner cavity of the oblique tip has barbs, and the barbs extend toward the direction close to the middle of the capsule shell.

8. The magnetic multi-needle biopsy capsule robot according to claim 1, characterized in that: Two partitions are fixedly connected in the capsule shell, and the two partitions divide the capsule shell into the left chamber, the middle chamber and the right chamber.

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