Registration pen for medical electromagnetic navigation

Abstract

The invention relates to a registration pen for medical electromagnetic navigation. The registration pen comprises a probe, a handle, a connecting cable and a connector, a small-diameter magnetic core coil is used as a sensitive element in the probe, and a magnetic core is made of a high-permeability amorphous wire material; the two coils with included angles are used for measuring the rolling angle of the probe; a PCB (Printed Circuit Board) is used as a substrate, and two coils are arranged on two sides of the substrate at a certain included angle or on the same side of the substrate; the probe uses tubular stainless steel as a shell, the tip is conical, and the sensitive element is packaged in the tube by glue; a pen-shaped plastic handle is used; and an ROM chip is arranged in the connector to record mapping parameter information. According to the invention, high-sensitivity measurement signals can be provided for six-degree-of-freedom space positioning and tracking, and data support can be provided for high-precision preoperative registration.

Description

Technical Field

[0001] The present invention relates to the technical field of sensors, and in particular to a registration pen for medical electromagnetic navigation. Background Art

[0002] Based on the electromagnetic field positioning principle, the electromagnetic tracking and positioning system can achieve non-contact and high-precision spatial positioning and tracking, and provide the position and attitude data of the positioning sensor in real time. When using a 5-degree-of-freedom positioning sensor, the spatial position coordinates and heading and pitch angle data of the sensor can be obtained. When using a 6-degree-of-freedom sensor, the roll angle data of the sensor can also be obtained. By arranging the sensor on medical devices, tools and other objects, the pose measurement and tracking of the measured object can be realized.

[0003] The electromagnetic positioning technology is currently widely used in the medical field to realize the positioning of various instruments and implants in the human body and assist in completing surgical operations. One type of application is for puncture positioning, such as for drainage, biopsy, etc. For example, in intracranial hematoma puncture navigation, the electromagnetic positioning technology is applied during the placement of the puncture tube. The guiding needle with a navigation element in the puncture tube is tracked and positioned graphically, and then the position and path of the puncture tube during the operation are displayed in real time, assisting the clinician to accurately and safely place the puncture tube at the intracranial hematoma site of the patient, improving the treatment efficiency and quality of the patient.

[0004] In addition to the positioning sensor that moves with the instrument, the electromagnetic positioning system also requires a reference sensor and a registration sensor. The registration sensor is used to establish the relationship between the CT / MRI image and the coordinate system of the positioning system. When the doctor actually uses it, the real-time position and trajectory of the instrument tip need to be accurately displayed on the two-dimensional CT / MRI image or in the three-dimensional model generated by reconstruction, so as to effectively guide the doctor's surgical operation.

[0005] The sensitivity of the registration sensor has a direct impact on its positioning accuracy, thereby affecting the accuracy of the registration process and the surgical positioning effect of the instrument. Summary of the Invention

[0006] In view of the above analysis, the present invention aims to disclose a registration pen for medical electromagnetic navigation, which can provide high-sensitivity measurement signals for 6-degree-of-freedom spatial positioning and tracking and provide data support for high-precision preoperative registration.

[0007] The present invention discloses a registration pen for medical electromagnetic navigation, which is used to cooperate with an alternating magnetic field for preoperative registration and positioning, and includes a probe, a handle, a connecting cable and a connector.

[0008] The probe includes a tubular housing with a conical tip at the front end, and two magnetosensitive elements arranged inside the tubular housing with a set installation angle.

[0009] Both of the magnetic sensitive elements are core coils with a high length-to-diameter ratio, and the core is made of a high magnetic permeability material; moreover, the relative positions, orientations, included angles, and installation positions of the two magnetic sensitive elements are stored in the registration pen as calibration data for positioning calibration during registration.

[0010] The handle is connected to the probe and is used for the operator to hold the registration pen during registration.

[0011] One end of the connecting cable passes through the inside of the handle and is connected to the coil leads of the two magnetic sensitive elements inside the probe, and the other end is connected to the connector.

[0012] The connector is a multi-pin connector and is used to connect the registration pen to the medical electromagnetic navigation device.

[0013] Further, a ROM chip is arranged inside the connector, and the calibration data including the relative positions, orientations, included angles, and installation positions of the two magnetic sensitive elements is stored in the ROM chip.

[0014] Further, the tubular outer shell included in the probe is of a thin-walled cylindrical tube structure; the wall thickness of the outer shell does not exceed 0.5 mm; the outer diameter of the outer shell is less than 6 mm; the conical tip is polished smoothly as the position where the registration pen contacts the human skin; the material of the outer shell is low-magnetic austenitic stainless steel.

[0015] Further, the inside of the tubular outer shell includes two magnetic sensitive elements and a substrate.

[0016] The two magnetic sensitive elements have the same size and structure, and both include a core and a fine enameled copper wire coil wound around the core; the core is made of a high magnetic permeability and low coercivity material including amorphous wire material.

[0017] The substrate is a PCB board; the length and width of the substrate match the length and inner diameter width of the internal space of the tubular outer shell; it is used to fixedly install the two magnetic sensitive elements in the internal space of the tubular outer shell, and provide lead pads for the coil leads of the two magnetic sensitive elements and cable pads for the connecting cable of the signal output of the magnetic sensitive elements; the lead pads and the cable pads are respectively connected through the traces and vias on the PCB.

[0018] Further, the two magnetic sensitive elements are installed on both sides or on the same side of the substrate by means of adhesive mounting, so that the two magnetic sensitive elements have a set installation included angle.

[0019] Further, the diameter of the core of the magnetic sensitive element is about 0.1 mm; the outer diameter of the coil is not more than 1 mm; the length of the coil is not less than 5 mm.

[0020] Further, the inside of the tubular outer shell includes a first magnetic sensitive element, a second magnetic sensitive element and a substrate.

[0021] Both the first magnetic sensitive element and the second magnetic sensitive element include a magnetic core and a fine enameled copper wire coil wound around the magnetic core; the magnetic core is made of a material with high magnetic permeability and low coercivity including amorphous wire material;

[0022] The first magnetic sensitive element is used to provide induction signals for measuring the pose of the registration pen in 5 degrees of freedom except for the rolling angle; the second magnetic sensitive element is used to provide induction signals for measuring the rolling angle of the registration pen; the first magnetic sensitive element has a longer coil and more turns relative to the second magnetic sensitive element to obtain high sensitivity;

[0023] The substrate is a PCB board; the length and width of the substrate match the internal space length and inner diameter width of the tubular housing; it is used to fixedly install two magnetic sensitive elements in the internal space of the tubular housing, position the first magnetic sensitive element at the center of the substrate with the magnetic core direction parallel to the long side direction of the substrate, position the second magnetic sensitive element at the center of the substrate with the magnetic core direction perpendicular to the long side direction of the substrate; and provide lead pads for the coil leads of the two magnetic sensitive elements and cable pads for the signal output cables of the magnetic sensitive elements; the lead pads and cable pads are respectively connected through traces and vias on the PCB.

[0024] Further, a slot for accommodating the first magnetic sensitive element is opened in the center of the substrate; the length and width of the slot are slightly larger than those of the first magnetic sensitive element to position the first magnetic sensitive element at the center of the substrate with the magnetic core direction parallel to the long side direction of the substrate, and the coil is also in the middle position in the thickness direction of the substrate; the second magnetic sensitive element is fixed on the substrate by means of paste mounting behind the slot position, so that the second magnetic sensitive element is positioned on the center line in the length direction of the substrate and the magnetic core is perpendicular to the magnetic core of the first magnetic sensitive element.

[0025] Further, the outer diameter of the coil of the second magnetic sensitive element is not greater than 1 mm, and the diameter of the magnetic core is about 0.1 mm; the length of the magnetic core is less than the inner diameter of the tubular housing to meet the installation margin;

[0026] The outer diameter of the coil of the first magnetic sensitive element is in the range of 2 - 3 mm, and the length of the magnetic core is 8 - 15 mm; the diameter of the magnetic core of the first magnetic sensitive element and the diameter of the fine enameled copper wire for winding the coil are the same as those of the second magnetic sensitive element, or a magnetic core thicker than that of the second magnetic sensitive element and / or a fine enameled copper wire thicker than that of the second magnetic sensitive element are used.

[0027] Further, the manufacturing and encapsulation process of the probe includes:

[0028] 1) Complete the paste fixing of the magnetic sensitive element coil on the substrate and the welding of each lead;

[0029] 2) Fix the front-end housing opening upward, insert the substrate into the front-end housing to the bottom. At this time, the constriction of the conical part will block the PCB. With a reasonably designed substrate size and tolerance, the substrate positioning is achieved.

[0030] 3) After placing the substrate, inject epoxy resin to a height that can cover the entire substrate and part of the cable.

[0031] 4) After the epoxy resin cures, the probe part encapsulation is completed.

[0032] It includes using a small-diameter coil with a magnetic core as the sensitive element, and the magnetic core is made of a high-permeability amorphous wire material; using two coils with an included angle to realize the measurement of the probe roll angle; using a PCB as the substrate, and the two coils are installed on both sides of the substrate or on the same side of the substrate at a certain included angle; using a tubular stainless steel as the front-end housing, with a conical tip, and the sensitive element is encapsulated in the tube with glue; using a pen-shaped plastic handle; placing a ROM chip in the connector to record mapping parameters and other information.

[0033] The present invention can achieve one of the following beneficial effects:

[0034] The registration pen for medical electromagnetic navigation disclosed by the present invention, as a high-sensitivity 6-degree-of-freedom registration sensor device, improves the measurement sensitivity and signal-to-noise ratio under an alternating magnetic field, has good reliability, and is convenient for holding and operating. The registration error can be less than 2 mm, which can effectively support the realization of high-precision preoperative registration. Description of the Drawings

[0035] The drawings are only for the purpose of showing specific embodiments and are not considered as a limitation to the present invention. Throughout the drawings, the same reference signs denote the same components.

[0036] Figure 1 It is a connection schematic diagram of the components of the registration pen for medical electromagnetic navigation in the embodiment of the present invention;

[0037] Figure 2 It is a schematic diagram of the internal structure of a probe part in the embodiment of the present invention;

[0038] Figure 3 It is another schematic diagram of the internal structure of a probe part in the embodiment of the present invention;

[0039] Figure 4 It is a schematic diagram of the structure of the registration pen after the handle is opened in the embodiment of the present invention.

[0040] Reference numerals: 1 - probe, 2 - handle, 3 - connecting cable, 4 - connector, 101 - housing, 102 - magnetosensitive element, 103 - magnetosensitive element, 104 - substrate, 105 - encapsulating epoxy resin, 106 - coil lead, 107 - coil lead, 108 - lead pad, 109 - lead pad, 110 - cable pad, 111 - cable pad, 112 - first magnetosensitive element, 113 - first magnetosensitive element, 114 - substrate, 115 - coil lead, 116 - coil lead, 117 - lead pad, 118 - lead pad, 119 - cable pad, 120 - cable pad, 201 - upper housing, 202 - lower housing, 203 - positioning post, 204 - positioning groove, 301 - cable lead, 302 - cable lead. Detailed implementation

[0041] The preferred embodiments of the present invention will be specifically described below in conjunction with the accompanying drawings, wherein the accompanying drawings form a part of this application and are used together with the embodiments of the present invention to explain the principles of the present invention.

[0042] An embodiment of the present invention discloses a registration pen for medical electromagnetic navigation, which is used to cooperate with an alternating magnetic field for pre - operative registration and positioning; as Figure 1 shown, it includes a probe, a handle, a connecting cable and a connector;

[0043] The probe includes a tubular housing with a conical tip at the front end, and two magnetosensitive elements arranged inside the tubular housing with a set installation angle;

[0044] Both of the two magnetosensitive elements are magnet - core coils with a high aspect ratio, and the magnetic core is made of a high - magnetic - permeability material; and the relative positions, directions, angles and installation positions of the two magnetosensitive elements are stored in the registration pen as calibration data for positioning calibration during registration; the installation position is the position relative to the tip of the probe.

[0045] The handle is connected to the probe and is used for an operator to hold the registration pen during registration;

[0046] One end of the connecting cable passes through the inside of the handle and is connected to the coil leads of the two magnetosensitive elements inside the probe, and the other end is connected to the connector;

[0047] The connector is a multi - pin connector; it is used to connect the registration pen to a medical electromagnetic navigation device; a ROM chip is arranged inside the connector, and the calibration data including the relative positions, directions, angles and installation positions of the two magnetosensitive elements is stored in the ROM chip;

[0048] The multi - pins include pins connected to the connecting cable, pins connected to the ROM chip, and some reserved pins.

[0049] Before performing preoperative registration and positioning, the registration pen is connected to the medical electromagnetic navigation device. The operator holds the registration pen and touches the tip of the probe to the pre-pasted registration points on the human body, so that the registration pen is within the working range of the magnetic field transmitter of the navigation device. The two magnetosensitive elements in the probe send the measurement signals obtained from the induced magnetic field signals to the medical electromagnetic navigation device, and the 5-degree-of-freedom spatial positions of the two magnetosensitive elements are calculated. Combining the 5-degree-of-freedom spatial positions of the two magnetosensitive elements and the calibration data of the probe, the 6-degree-of-freedom spatial position of the conical tip of the probe in contact with the registered human body part is located, realizing accurate preoperative position registration.

[0050] Specifically, the tubular outer shell of the probe is a thin-walled cylindrical tube structure; the wall thickness of the outer shell is determined according to the required strength in actual use; generally, it does not exceed 0.5 mm, and preferably is 0.3 mm; the outer diameter of the outer shell is less than 6 mm; the conical tip is polished smoothly as the position where the registration pen contacts the human skin; the material of the outer shell is low-magnetic austenitic stainless steel, which needs to meet the relevant medical device standards, such as 304, 316, 316L stainless steel.

[0051] In a specific solution of this embodiment, as Figure 2 shown, the inside of the tubular outer shell includes two magnetosensitive elements and a substrate;

[0052] The two magnetosensitive elements have the same size and structure, and each includes a magnetic core and a fine enameled copper wire coil wound around the magnetic core; the magnetic core is made of a material with high magnetic permeability and low coercivity including amorphous wire material;

[0053] The substrate is a PCB board; the length and width of the substrate match the length and inner diameter width of the internal space of the tubular outer shell; it is used to fixedly install the two magnetosensitive elements in the internal space of the tubular outer shell, and provide lead pads for the coil leads of the two magnetosensitive elements, and provide cable pads for the connection cables of the signal output of the magnetosensitive elements; the lead pads and the cable pads are respectively connected through the traces and vias on the PCB.

[0054] Specifically, the two magnetosensitive elements are installed on both sides or on the same side of the substrate by means of pasting, so that the two magnetosensitive elements have a set installation angle.

[0055] When installed by pasting on both sides, a pair of double-sided pads are provided on both sides of the PCB near the installation positions of the magnetosensitive elements, which are respectively used for soldering the coil leads of the magnetosensitive elements pasted on this side; on one side of the substrate far from the tip of the tubular outer shell, 4 cable pads are also provided; the 4 cable pads are respectively connected to the pair of double-sided pads through the traces and vias on the PCB in a one-to-one correspondence; the 4 cable pads are the soldering pads on the PCB for the 4 connection cables of the signal output of the magnetosensitive elements.

[0056] To achieve sufficient space within a tubular housing with an outer diameter less than 6 mm to accommodate the installation angle of two magnetic sensitive elements and to meet the requirements of sensitivity and magnetic permeability for the magnetic sensitive elements; in a preferred embodiment, the diameter of the magnetic core of the magnetic sensitive element is about 0.1 mm; the outer diameter of the coil is not greater than 1 mm; and the length of the coil is not less than 5 mm.

[0057] In another specific embodiment of the present example, as Figure 3 shown, the interior of the tubular housing includes two magnetic sensitive elements and a substrate;

[0058] The first magnetic sensitive element and the second magnetic sensitive element each include a magnetic core and a fine enameled copper wire coil wound around the magnetic core; the magnetic core is made of a high magnetic permeability and low coercivity material including amorphous wire material;

[0059] The first magnetic sensitive element is used to provide induction signals for measuring the pose of 5 degrees of freedom of the registration pen except for the rolling angle; the second magnetic sensitive element is used to provide induction signals for measuring the rolling angle of the registration pen; the first magnetic sensitive element has a longer coil and more turns relative to the second magnetic sensitive element; to obtain high sensitivity.

[0060] The substrate is a PCB board; the length and width of the substrate match the length and inner diameter width of the interior space of the tubular housing; it is used to fixedly install the two magnetic sensitive elements in the interior space of the tubular housing, position the first magnetic sensitive element at the center of the substrate with the magnetic core direction parallel to the long side direction of the substrate, position the second magnetic sensitive element at the center of the substrate with the magnetic core direction perpendicular to the long side direction of the substrate; and provide lead pads for the coil leads of the two magnetic sensitive elements and cable pads for the signal output cables of the magnetic sensitive elements; the lead pads and the cable pads are respectively connected through traces and vias on the PCB.

[0061] As Figure 3 shown, a slot for accommodating the first magnetic sensitive element is opened in the center of the substrate; the length and width of the slot are slightly larger than the first magnetic sensitive element, so that the first magnetic sensitive element is positioned at the center of the substrate with the magnetic core direction parallel to the long side direction of the substrate, and the coil is also in the middle position in the thickness direction of the substrate; the second magnetic sensitive element is fixed to the substrate by means of adhesive mounting behind the slot position, so that the second magnetic sensitive element is positioned on the center line in the length direction of the substrate and the magnetic core is perpendicular to the magnetic core of the first magnetic sensitive element.

[0062] In a more preferred embodiment, the outer diameter of the coil of the second magnetic sensitive element is not greater than 1 mm, the diameter of the magnetic core is about 0.1 mm; the length of the magnetic core is less than the inner diameter of the tubular housing, meeting the installation margin;

[0063] The outer diameter of the coil of the first magnetic sensitive element is in the range of 2-3 mm, and the length of the magnetic core is in the range of 8-15 mm; the diameter of the magnetic core of the first magnetic sensitive element and the diameter of the thin enameled copper wire wound around the coil are the same as those of the second magnetic sensitive element, or a magnetic core with a thicker diameter than that of the second magnetic sensitive element and / or a thin enameled copper wire with a thicker diameter than that of the second magnetic sensitive element are used.

[0064] The first magnetic sensitive element is bonded and positioned with the substrate using quick-drying glue or UV glue and fixed in the groove in the center of the substrate. Since the length of the first magnetic sensitive element and the outer diameter of the coil are greater than those of the second magnetic sensitive element, the coil of the first magnetic sensitive element is longer, has more turns, and has higher sensitivity, thereby improving the sensitivity of the induction signal of the five degrees of freedom posture measurement except the rolling angle on the signal source. At the same time, since the thermal noise of the sensor is inversely proportional to its resistance, the use of a thicker diameter thin enameled copper wire to wind the coil can further improve the sensor signal-to-noise ratio, and the use of a thicker magnetic core can increase the effective magnetic permeability.

[0065] exist Figure 3 In the installation mode, only one side of the installation surface of the second magnetic sensitive element is provided on the substrate, and four lead pads are used to respectively weld the coil leads of the two magnetic sensitive elements; four cable pads are also provided on the substrate on the same side of the substrate away from the tip of the tubular shell; the four cable pads are respectively connected to the four lead pads through routing and via connections on the PCB; the four cable pads serve as welding pads on the PCB board for four connecting cables for signal output of the magnetic sensitive element.

[0066] like Figure 2 and Figure 3 The manufacturing and packaging process of the probe of the structure shown includes:

[0067] 1) Complete the pasting and fixing of the magnetic sensitive element coil on the substrate and the welding of each lead;

[0068] 2) Fix the front housing opening upwards and insert the substrate into the front housing to the bottom. At this time, the closing part of the tapered part will block the PCB. With the reasonably designed substrate size and tolerance, the substrate positioning is achieved;

[0069] 3) After the substrate is placed, inject epoxy resin to a height that can cover the entire substrate and part of the cables;

[0070] 4) After the epoxy resin is cured, the probe part is encapsulated.

[0071] like Figure 4As shown, the handle consists of a lower housing and an upper housing. During installation, holes are drilled on both sides at the end of the probe housing for positioning with positioning posts. The connecting cable is embedded in the positioning groove in the lower housing. After arranging the cable, the upper and lower housings are bonded together to form a pen-shaped handle, and the cable passes through the inside of the handle. The handle housing is made of plastic and is sized for easy gripping. The shape and size of the handle do not affect the measurement performance of the sensor.

[0072] Connecting cable, Figure 1 In 3, two pairs of twisted enameled wires are used inside. Each pair of twisted wires is connected to a coil through a PCB pad respectively. The cable has no shielding layer, and the outer diameter and material of the cable sheath are selected according to actual needs. In addition, a shielding layer can be added and grounded to improve the anti-interference ability. The twisted wires can be enameled wires or conventional insulated wires, but cables that are not twisted inside and have no shielding should not be used. The cable length is usually not less than 2 meters and is determined according to actual needs.

[0073] Connector, a commercial connector can be used. The material is plastic and is determined in combination with the host interface of the medical electromagnetic navigation device, not limited to a specific model. There should be enough space inside the connector to install a ROM chip for storing the mapping parameters and other information of the sensor.

[0074] The number of pins inside the connector is not less than 7. Among them, 4 pins are connected to the sensor cable, and at least 2 pins are used for the ROM chip. Currently, the connector used is a 9-pin connector, with 3 pins reserved.

[0075] The mapping process of the calibration data of the registration pen disclosed in this embodiment includes:

[0076] 1) Use a tooling to set the reference point, which is usually a shallow circular pit to facilitate the positioning of the tip of the registration pen probe therein;

[0077] 2) Connect the registration pen to be mapped to the medical electromagnetic navigation device to make the medical electromagnetic navigation device work properly;

[0078] 3) Press the tip of the registration pen probe against the mapping reference point and use the medical electromagnetic navigation device to collect measurement data;

[0079] 4) According to the collected data, calculate the 5-axis degree-of-freedom pose measurement data of the two magnetic sensitive elements respectively;

[0080] 5) According to the 5-degree-of-freedom (3 position coordinates, 1 azimuth angle, and 1 pitch angle) pose measurement data of the two magnetic sensitive elements, calculate the relative position, direction, and included angle of the two magnetic sensitive elements, and use the midpoint of the position coordinates of the two magnetic sensitive elements as the comprehensive position of the sensitive element for subsequent mapping calculations;

[0081] 6) Change the posture of the registration pen and conduct multiple measurements. Since the position of the tip of the registration pen remains unchanged during each measurement, the spatial position of the tip of the registration pen can be calculated, thereby obtaining the relative installation positions of the tip of the registration pen and the two magnetosensitive elements to form calibration data;

[0082] 7) Store the calibration data in the ROM chip; complete the mapping of the calibration data of the registration pen.

[0083] As mentioned above, it is only the preferred specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A registration pen for medical electromagnetic navigation, characterized in that, For preoperative registration and positioning in cooperation with an alternating magnetic field; it includes a probe, a handle, a connecting cable and a connector; The probe includes a tubular housing with a conical tip at the front end, and two magnetosensitive elements arranged inside the tubular housing with a set installation angle; Both of the two magnetosensitive elements are magnetically core coils with a high aspect ratio, and the magnetic core is made of a high magnetic permeability material; and the relative positions, directions, angles and installation positions of the two magnetosensitive elements are stored in the registration pen as calibration data for positioning calibration during registration; The handle is connected to the probe and is used for the operator to hold the registration pen during registration; One end of the connecting cable passes through the inside of the handle and is connected to the coil leads of the two magnetosensitive elements inside the probe, and the other end is connected to the connector; The connector is a multi-pin connector; it is used to connect the registration pen to a medical electromagnetic navigation device.

2. The registration pen for medical electromagnetic navigation according to claim 1, characterized in that, An ROM chip is arranged inside the connector, and the calibration data including the relative positions, directions, angles and installation positions of the two magnetosensitive elements is stored in the ROM chip.

3. The registration pen for medical electromagnetic navigation according to claim 1, characterized in that, The tubular housing included in the probe is a thin-walled cylindrical tube structure; the wall thickness of the housing does not exceed 0.5 mm; the outer diameter of the housing is less than 6 mm; the conical tip is polished smoothly at the position where the registration pen contacts the human skin; the housing material is a low-magnetic austenitic stainless steel.

4. The registration pen for medical electromagnetic navigation according to claim 1, characterized in that, The inside of the tubular housing includes two magnetosensitive elements and a substrate; The two magnetosensitive elements have the same size and structure, and both include a magnetic core and a fine enameled copper wire coil wound around the magnetic core; the magnetic core is made of a high magnetic permeability and low coercivity material including amorphous wire material; The substrate is a PCB board; the length and width of the substrate match the length and inner diameter width of the inner space of the tubular housing; it is used to fixedly install the two magnetosensitive elements in the inner space of the tubular housing, and provide lead pads for the coil leads of the two magnetosensitive elements and cable pads for the connecting cable of the signal output of the magnetosensitive elements; the lead pads and the cable pads are respectively connected through the traces and vias on the PCB.

5. The registration pen for medical electromagnetic navigation according to claim 4, characterized in that, The two magnetosensitive elements are installed on both sides or on the same side of the substrate by a pasting installation method, so that the two magnetosensitive elements have a set installation angle.

6. The registration pen for medical electromagnetic navigation according to claim 4, characterized in that, The diameter of the magnetic core of the magnetosensitive element is about 0.1 mm; the outer diameter of the coil is not greater than 1 mm; the length of the coil is not less than 5 mm.

7. The registration pen for medical electromagnetic navigation according to claim 1, characterized in that, The inside of the tubular housing includes a first magnetosensitive element, a second magnetosensitive element and a substrate; The first magnetic sensitive element and the second magnetic sensitive element both include a magnetic core and a fine enameled copper wire coil wound on the magnetic core; the magnetic core is made of a high magnetic permeability and low coercive force material including an amorphous wire material; The first magnetic sensitive element is used to provide an induction signal for measuring the five degrees of freedom posture of the registration pen except the rolling angle; the second magnetic sensitive element is used to provide an induction signal for measuring the rolling angle of the registration pen; the first magnetic sensitive element uses a longer coil and more turns than the second magnetic sensitive element; To obtain high sensitivity; The substrate is a PCB board; the length and width of the substrate match the length and inner diameter width of the inner space of the tubular housing; it is used to fix the two magnetic sensitive elements in the inner space of the tubular housing, so that the first magnetic sensitive element is positioned at the center of the substrate, the magnetic core direction is parallel to the long side direction of the substrate, and the second magnetic sensitive element is positioned at the center of the substrate, the magnetic core direction is perpendicular to the long side direction of the substrate; and lead pads are provided for the coil leads of the two magnetic sensitive elements, and cable pads are provided for the signal output cables of the magnetic sensitive elements; the lead pads and the cable pads are respectively connected correspondingly through routing and via connections on the PCB.

8. The medical electromagnetic navigation registration pen according to claim 7, characterized in that: A groove for accommodating a first magnetic sensitive element is opened in the center of the substrate; the length and width of the groove are slightly larger than the first magnetic sensitive element, so that the first magnetic sensitive element is positioned in the center of the substrate, the magnetic core direction is parallel to the long side direction of the substrate, and the coil is also located in the middle position in the thickness direction of the substrate; the second magnetic sensitive element is fixed to the substrate by gluing and installing behind the groove position, so that the second magnetic sensitive element is positioned on the center line of the length direction of the substrate, and the magnetic core is perpendicular to the magnetic core of the first magnetic sensitive element.

9. The medical electromagnetic navigation registration pen according to claim 8, characterized in that: The outer diameter of the coil of the second magnetic sensitive element is no more than 1 mm, and the diameter of the magnetic core is about 0.1 mm; the length of the magnetic core is less than the inner diameter of the tubular housing, satisfying the installation margin; The outer diameter of the coil of the first magnetic sensitive element is in the range of 2-3 mm, and the length of the magnetic core is in the range of 8-15 mm; the diameter of the magnetic core of the first magnetic sensitive element and the diameter of the thin enameled copper wire wound around the coil are the same as those of the second magnetic sensitive element, or a magnetic core with a thicker diameter than that of the second magnetic sensitive element and / or a thin enameled copper wire with a thicker diameter than that of the second magnetic sensitive element are used.

10. The medical electromagnetic navigation registration pen according to claim 4 or 7, characterized in that: The probe manufacturing and packaging process includes: 1) Complete the pasting and fixing of the magnetic sensitive element coil on the substrate and the welding of each lead; 2) Fix the front housing opening upwards and insert the substrate into the front housing to the bottom. At this time, the closing part of the tapered part will block the PCB. With the reasonably designed substrate size and tolerance, the substrate positioning is achieved; 3) After the substrate is placed, inject epoxy resin to a height that can cover the entire substrate and part of the cables; 4) After the epoxy resin is cured, the probe part is encapsulated.

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