Magnetic sensor system, magnetic sensor unit and processing device

Abstract

To provide a magnetic sensor system that can enhance accuracy in calculating a rotation angle of a wire such as a guide wire for operation of a medical device such as a catheter when delivering the wire.SOLUTION: A magnetic sensor system comprises: a cylindrical body 12 formed with a lumen 123 extending from a rear end part 122 to a front end part 121; a magnet 13 that is arranged at the rear end part 122; a first magnetic sensor 14 that is arranged at a first position p1 between the front end part 121 and the rear end part 122; and a processing device 16 that processes data acquired from the first magnetic sensor 14. The magnet 13 magnetizes a target area being a part of a wire W when the wire W including a magnetism substance enters the lumen 123. The first magnetic sensor 14 detects a first magnetization state s1 of the target area Wt when the target area Wt is arranged at the first position p1. The processing device 16 includes a rotation angle calculation unit 161 that calculates a rotation angle θ1 of the target area Wt on the basis of the first magnetization state s1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to magnetic sensors. [Background technology]

[0002] Patent Document 1 introduces a technology in which a ring-shaped encoder is magnetized and attached to a rotating body such as a steering shaft, multiple magnetic sensors are arranged around the encoder, and changes in the magnetic force distribution of the encoder are detected to calculate the rotation angle of the rotating body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-242205 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for measuring the rotation state of a wire, such as a guidewire, used to operate a medical device such as a catheter when delivering the wire. However, because the wire has a weak coercive force, it is easily affected by external magnetic fields during delivery, and the magnetic force distribution is easily changed. This has led to a problem in that when a wire, such as a guidewire used to operate a medical device such as a catheter, is delivered, the detection accuracy of the magnetic force distribution in the target area decreases, and the accuracy of calculating the rotation angle of the wire decreases.

[0005] Therefore, an object of the present disclosure is to provide a magnetic sensor system that can improve the accuracy of calculating the rotation angle of the wire. [Means for solving the problem]

[0006] In order to solve the above problems, the magnetic sensor system of the present disclosure includes a magnetic sensor unit and a processing device that processes data acquired from the magnetic sensor, wherein the magnetic sensor unit includes a cylindrical body forming a lumen extending from a rear end to a front end, a magnet disposed at the rear end, and a first magnetic sensor disposed at a first position between the front end and the rear end, wherein the magnet magnetizes a target area that is a part of the wire containing a magnetic material when the wire enters the lumen, and the first magnetic sensor detects a first magnetization state of the target area when the target area is disposed at the first position, and the processing device includes a rotation angle calculation means that calculates a rotation angle of the target area based on the first magnetization state.

[0007] According to the magnetic sensor system of the present disclosure, the target area is magnetized each time the target area passes near the magnet, which has the effect of compensating for the weak magnetic coercivity of the wire and improving the accuracy of calculating the rotation angle of the wire. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram of a magnetic sensor system according to the present disclosure. [Figure 2] 1A is a schematic end view of the magnetic sensor unit at a magnet position p0, FIG. 1B is a schematic end view of the magnetic sensor unit at a magnet position p2, and FIG. 1C is a schematic end view of the magnetic sensor unit at a magnet position p1. [Figure 3] FIG. 2 is a schematic diagram showing the positional relationship between a magnetic sensor unit and a target area. [Figure 4] FIG. 1 is a block diagram of a magnetic sensor system. [Figure 5] (a) Schematic diagram showing the magnetic measurement area, (b) Schematic diagram showing the magnetic flux. [Figure 6] FIG. 2 is a schematic diagram showing magnetic measurement positions. [Figure 7] 10 is a graph showing a magnetic force distribution for calculating a passing position. [Figure 8] 10 is a graph showing a magnetic force distribution for calculating a rotation angle. [Figure 9] 10 is a flowchart showing a procedure for calculating a rotation angle. [Figure 10] 10 is a flowchart showing a procedure for calculating an angular velocity. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment in which the present disclosure is embodied in a magnetic sensor system will be described with reference to the drawings.

[0010] As shown in FIG. 1(a), a magnetic sensor system 1 is used to measure the rotational state of a wire W, such as a guide wire, inserted into a medical device 2, such as a catheter. The magnetic sensor system 1 is attached to a Y-shaped connector 3 for manipulating the wire W when in use. As shown in FIG. 1(b), the magnetic sensor system 1 includes a magnetic sensor unit 11, a processing device 16 that processes data acquired from the magnetic sensor unit 11, and a storage device 17 that stores a magnetic force distribution m1 for calculating a passing position and a magnetic force distribution m2 for calculating a rotation angle.

[0011] 1(b) and 2, the magnetic sensor unit 11 includes a cylindrical body 12 having a lumen 123 extending from a rear end 122 to a front end 121, a magnet 13 disposed at the rear end 122, a first magnetic sensor 14 disposed at a first position p1 between the front end 121 and the rear end 122, and a second magnetic sensor 15 disposed at a second position p2 between the first position p1 and the rear end 122. In the following description, the position where the magnet 13 is disposed will be referred to as magnet position p0.

[0012] As shown in FIG. 3(a), the magnet 13 magnetizes the target area Wt, which is a part of the wire W containing a magnetic material, when the wire W enters the lumen 123. In other words, the magnet 13 magnetizes the target area Wt when the target area Wt is located at magnet position p0. The magnet 13 is ring-shaped and arranged coaxially with the lumen 123. Because the target area Wt is magnetized every time the target area Wt passes inside the ring of the ring-shaped magnet 13, this compensates for the weak coercive force of the wire W and improves the detection accuracy of the magnetic force distribution in the target area Wt.

[0013] As shown in FIG. 3(b), the first magnetic sensor 14 detects the first magnetic state s1 of the target area Wt when the target area Wt is placed at the first position p1.

[0014] As shown in FIG. 3(c), the second magnetic sensor 15 detects the second magnetic state s2 of the target area Wt when the target area Wt is positioned at a second position p2. A plurality of second magnetic sensors 15 can be arranged. The plurality of second magnetic sensors 15-1, 15-2 are arranged at positions that are shifted in phase by 90 degrees in the circumferential direction of the lumen 123. By arranging a plurality of second magnetic sensors 15, the passing position calculation unit 163 (see FIG. 4) can calculate the passing position pt with higher accuracy.

[0015] 4, the processing device 16 includes a rotation angle calculation unit 161 that calculates a rotation angle θ1 of the target area Wt at a first position p1 based on the first magnetic state s1, an angular velocity calculation unit 162 that calculates the angular velocity ω of the target area Wt, a passing position calculation unit 163 that calculates a passing position pt at which the target area Wt passes through the magnet 13, and a timer 164 that measures a movement time t for the target area Wt to ​​move from the second position p2 to the first position p1. The rotation angle calculation unit 161 can also calculate a rotation angle θ2 of the target area Wt at the second position p2 based on the second magnetic state s2.

[0016] The storage device 17 includes a recording unit 171 that stores calculated data, and a database 172 that stores magnetic force distributions m1, m2, etc. The recording unit 171 includes a passing position recording unit that stores the passing position pt at which the target area Wt passes through the magnet 13, a rotation angle recording unit that stores the rotation angles θ1, θ2 of the target area Wt, and an angular velocity recording unit that stores the angular velocity ω of the target area Wt. The database 172 stores program data, a magnetic force distribution m1 for calculating the passing position (see FIG. 7), and a magnetic force distribution m2 for calculating the rotation angle (see FIG. 8).

[0017] As shown in FIG. 5(a), the passing position pt is a position included in the cross-sectional area 131 at the magnet position p0, and indicates the positional deviation from the center of the ring of the magnet 13. As shown in FIG. 5(b), the magnetic field in the cross-sectional area 131 is not uniform. Therefore, the magnetization state of the target area Wt changes depending on the passing position pt. Therefore, in the present disclosure, the passing position pt is calculated to improve the calculation accuracy of the rotation angle θ1. This will be explained in detail below.

[0018] Figure 6 shows positions A1, A2, B1, B2, C1, and C2 where magnetic force distribution m1 was measured, and positions pa, pb, pc, pd, and pe where magnetic force distribution m2 was measured. Figure 7 shows magnetic force distribution m1 at positions A1, A2, B1, B2, C1, and C2. Furthermore, Figure 8 shows magnetic force distribution m2 at positions pa, pb, pc, pd, and pe.

[0019] The passing position calculation unit 163 compares the second magnetic states s2-1 and s2-2 detected by the second magnetic sensors 15-1 and 15-2 with the magnetic force distribution m1 at the positions A1, A2, B1, B2, C1, and C2, respectively. For example, when the second magnetic states s2-1 and s2-2 are near "(X, Y, Z) = (100, 0, 250)," the passing position calculation unit 163 compares the second magnetic states s2-1 and s2-2 with the magnetic force distribution m1 at the positions A1 and B2, and determines that the passing position pt is the position pa. In this embodiment, the passing position calculation unit 163 is configured to map the passing position pt to any of the positions pa, pb, pc, pd, and pe. In other embodiments, the number of positions pa, etc. may be increased to calculate the passing position pt more precisely.

[0020] The rotation angle calculation unit 161 calculates the rotation angle θ1 from the passing position pt, the first magnetic state s1 detected by the first magnetic sensor 14, and the magnetic force distribution m2 at the positions pa, pb, pc, pd, and pe. The rotation angle θ1 can be calculated based on the X-axis in the graph of the positions pa and pe, the Y-axis in the graph of the positions pb and pd, and the Z-axis in the graph of the position pc. For example, when the passing position pt=position pa and the first magnetic state s1 is "X=600," the rotation angle calculation unit 161 refers to the magnetic force distribution m2 at the position pa and calculates "rotation angle θ1=135 degrees." By performing correction using the passing position pt in this way, the rotation angle calculation unit 161 can calculate the rotation angle θ1 with higher accuracy than when no correction is performed.

[0021] The angular velocity calculation unit 162 calculates the rotation angle θ2 based on the second magnetic state s2 detected by the second magnetic sensor 15, and calculates the rotation angle θ1 based on the first magnetic state s1 detected by the first magnetic sensor 14. At this time, when calculating the rotation angle θ2 based on the second magnetic state s2, the rotation angle calculation unit 161 can calculate the rotation angle θ2 by assuming that the target area Wt has passed through the center of the magnet 13 (passing position pt = position pc). The passing position calculation unit 163 calculates the passing position pt, and the rotation angle θ1 can be calculated using the calculated passing position pt. The angular velocity calculation unit 162 calculates the angular velocity ω of the wire W based on the difference between the rotation angles θ2 and θ1 and the moving time t required for the target area Wt to ​​move from the second position p2 to the first position.

[0022] Next, a procedure for calculating the rotation angle θ1 in the magnetic sensor system 1 configured as above will be described with reference to FIG.

[0023] When the doctor inserts the wire W into the lumen 123, the target area Wt is magnetized (S11). When the target area Wt is located at the second position p2, the second magnetic sensor 15-1 detects the second magnetic state s2-1 (S12), and the second magnetic sensor 15-2 detects the second magnetic state s2-2 (S13). The passing position calculation unit 163 compares the second magnetic states s2-1 and s2-2 with the magnetic force distribution m1, respectively, and calculates the passing position pt (S14). The processing device 16 stores the calculated passing position pt in the passing position recording unit.

[0024] After that, when the target area Wt is placed at the first position p1, the first magnetic sensor 14 detects the first magnetic state s1 (S15). The processing device 16 refers to the magnetic force distribution m2 corresponding to the passing position pt in the database 172, and calculates the rotation angle θ1 based on the magnetic force distribution m2 and the first magnetic state s1 (S16). The processing device 16 stores the calculated rotation angle θ1 in the rotation angle recording unit. If the measurement of the rotation angle θ1 is to be continued (S17: No), the process returns to the detection of the second magnetic state s2 by the second magnetic sensor (S12).

[0025] Next, the procedure for calculating the angular velocity ω will be described with reference to Fig. 10. In the following explanation, explanations that overlap with the procedure for calculating the rotation angle θ1 will be omitted.

[0026] When the wire W is advanced into the lumen 123, the target area Wt is magnetized (S21). When the target area Wt is placed at the second position p2, the processing device 16 initializes a timer (S22).

[0027] The rotation angle calculation unit 161 calculates the rotation angle θ2 based on the second magnetization state s2 (S23). The processing device 16 stores the calculated rotation angle θ2 in the rotation angle recording unit. When the target area Wt is placed at the first position p1, the rotation angle calculation unit 161 calculates the rotation angle θ1 based on the first magnetization state s1 (S24). The processing device 16 stores the calculated rotation angle θ1 in the rotation angle recording unit.

[0028] The angular velocity calculation unit 162 acquires the rotation angles θ2 and θ1 from the rotation angle recording unit, and acquires the movement time t taken for the target area Wt to ​​move from the second position p2 to the first position from the timer 164 (S25). The angular velocity calculation unit 162 calculates the angular velocity ω of the wire W based on the difference between the rotation angles θ2 and θ1 and the movement time t taken for the target area Wt to ​​move from the second position p2 to the first position (S26). The processing device 16 stores the calculated angular velocity ω in the angular velocity recording unit. If measurement of the angular velocity ω is to be continued (S27: No), the process returns to initialization of the timer 164 (S22).

[0029] Therefore, according to the magnetic sensor system 1 of this embodiment, the magnetic force distribution m1 for each passing position and the magnetic force distribution m2 for each rotation angle are stored in the database 172, and the rotation angle θ1 is calculated based on these magnetic force distributions m1 and m2, thereby improving the calculation accuracy of the rotation angle θ1.

[0030] For example, when performing a procedure using a guidewire, a doctor can first pass the guidewire through the lumen 123 of the magnetic sensor system 1 of the present disclosure and then insert it into the patient's body, thereby determining how much the guidewire has been rotated inside the patient's body. The rotation angle recording unit can then accumulate data (rotation angle data) related to the guidewire rotation angle θ1 for each type of procedure or each type of region through which the guidewire is passed. As a result, using the accumulated rotation angle data can contribute to improving the accuracy of a procedure, for example, when using AI to perform a guidewire procedure. Even if it is a procedure that a doctor is attempting for the first time, the doctor can perform the procedure accurately and efficiently.

[0031] The present disclosure is not limited to the above-described embodiments, and for example, as exemplified below, it is possible to appropriately change the shape and configuration of each part within the scope of the present disclosure.

[0032] (1) The magnet 13 is provided at the distal end portion 121. In this case, when the wire W is delivered in the reverse direction, the target area Wt entering the lumen 123 from the distal end portion 121 is re-magnetized, thereby improving the detection accuracy of the magnetic force distribution in the target area Wt. (2) The recording unit 171 and the database 172 of the storage device 17 are arranged in separate storage devices. For example, only the database 172 is arranged in an external server. (3) When calculating the rotation angle θ1 at the first position p1, calculation of the passing position pt is omitted, and the rotation angle θ1 is calculated assuming that the target region Wt passes through the center of the cross-sectional region 131 of the magnet 13. In this case, the passing position pt is set to be equal to the position pc, and the rotation angle θ1 is calculated based on the magnetic force distribution m2 at the position pc. (4) Repeating steps S23 and S24 in Fig. 10 multiple times. By repeating steps multiple times, errors can be reduced.

[0033] The functions performed by the components described herein may be implemented in circuitry or processing circuitry, including general-purpose processors, application-specific processors, integrated circuits, ASICs (Application Specific Integrated Circuits), a CPU (a Central Processing Unit), conventional circuits, and / or combinations thereof, programmed to perform the described functions. A processor includes transistors and other circuits and is considered to be circuitry or processing circuitry. A processor may also be a programmed processor that executes a program stored in a memory.

[0034] In this specification, a circuit, unit, or means is hardware that is programmed to realize or executes a described function. The hardware may be any hardware disclosed herein or any hardware known to be programmed to realize or execute the described function. If the hardware is a processor, which is considered a type of circuitry, the circuit, means, or unit is a combination of hardware and software used to configure the hardware and / or processor.

Claims

1. a magnetic sensor unit; and a processing device that processes data acquired from the magnetic sensor unit; the magnetic sensor unit includes a cylindrical body having a lumen extending from a rear end to a front end, a magnet disposed at the rear end, and a magnetic sensor disposed at a predetermined position between the front end and the rear end, The magnet magnetizes a target area that is a part of the wire containing a magnetic material when the wire enters the lumen, the magnetic sensor detects a magnetized state of the target area when the target area is placed at the predetermined position; The processing device includes a rotation angle calculation means for calculating a rotation angle of the target area based on the magnetized state.

2. the predetermined position is a first position, the magnetic sensor is a first magnetic sensor, the magnetic state is a first magnetic state, the magnetic sensor unit includes a second magnetic sensor disposed at a second position between the first position and the rear end, the second magnetic sensor detects a second magnetic state of the target area when the target area is disposed at the second position; The magnetic sensor system according to claim 1 , wherein the rotation angle calculation means calculates the rotation angle of the target area based on the first magnetic state and the second magnetic state.

3. 3. The magnetic sensor system according to claim 2, wherein the processing device includes angular velocity calculation means for calculating an angular velocity of the target area based on the first magnetic state and the second magnetic state.

4. a storage device that stores the magnetic force distribution of the magnet; the processing device includes a passing position calculation means for calculating a passing position where the target area passes through the magnet, The magnetic sensor system according to claim 2 , wherein the passing position calculation means calculates the passing position based on the magnetic force distribution and the second magnetization state.

5. The device comprises a cylindrical body having a lumen extending from a rear end to a front end, a magnet disposed at the rear end, and a magnetic sensor disposed at a predetermined position between the front end and the rear end, The magnet magnetizes a target area that is a part of the wire containing a magnetic material when the wire enters the lumen, The magnetic sensor is a magnetic sensor unit that detects the magnetized state of the target area when the target area is placed at the predetermined position.

6. A processing device that processes data acquired from a magnetic sensor unit, the magnetic sensor unit includes a cylindrical body having a lumen extending from a rear end to a front end, a magnet disposed at the rear end, and a magnetic sensor disposed at a predetermined position between the front end and the rear end, The magnet magnetizes a target area that is a part of the wire containing a magnetic material when the wire enters the lumen, the magnetic sensor detects a magnetized state of the target area when the target area is placed at the predetermined position; a processing device including a rotation angle calculation means for calculating a rotation angle of the target area based on the magnetized state.

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