JP6924443B2 - 3D magnetic field detector - Google Patents

Description

The present invention relates to an ultra-compact three-dimensional magnetic field detection device applied to an in vivo magnetic positioning system such as an endoscope and a catheter.

With the sophistication of the medical field, in-vivo motion devices such as gastrocameras, catheters, and angioscopes are becoming widespread, and it is becoming necessary to grasp their positions and orientations. A method of incorporating a magnet or electromagnet on the device side and measuring its position and orientation externally with a magnetic field sensor (Patent Document 1), or installing it at two points where the position is specified with the uniaxial magnetic field sensor on the device side. A method in which two magnetic field sensors and an external magnetic field generator are combined (Patent Document 2) and a method in which three external magnetic field generators and a three-dimensional magnetic field sensor built in the tip of a guide are combined (Patent Document 3). The method is disclosed. However, the minute magnetic field detection force of the magnetic sensor is low, and therefore the positioning accuracy is several mm, which is less than the clinically required accuracy of 100 μm or less.

In 2015, the "GSR sensor" (Patent Document 4) was disclosed as an ultra-sensitive micromagnetic sensor, and efforts are underway to realize a positioning accuracy of 100 μm by utilizing this magnetic sensor.
As a magnetic sensor with a built-in catheter, a 3D magnetic field in which a small 3D magnetic field detection element (length 0.6 mm or less, width 0.3 mm or less and thickness 0.15 mm or less) and ASIC are flip-chip bonded using a GSR sensor. The detection device is shown in FIG. 11 (Patent Document 5, FIG. 1). However, since the magnetic field detection sensitivity in the Z-axis direction is not sufficient as compared with the X-axis and Y-axis directions, it is necessary to increase the thickness of the sensor in the Z-axis direction when the detection of the Z-axis magnetic field is strengthened. That is, there is a trade-off relationship between the thickness of the sensor and the magnetic field detection sensitivity in the Z-axis direction, and its improvement is a difficult task.

Further, as a magnetic sensor built in the guide wire for guiding the catheter, a uniaxial magnetic field sensor type is shown in FIG. 12 (Patent Documents 6 and 1) in place of the triaxial magnetic field sensor in 2017. In this method, the space for the built-in sensor at the tip of the guide wire is very small, 0.5 mm in diameter and 1.6 mm or less in length. A positioning accuracy of 100 μm or less is achieved by a method in which a three-axis uniform magnetic field is alternately applied to obtain the position and orientation. However, the magnetic field generator

The structure of the device is complicated, and there is a drawback that the treatment space for doctors to treat is narrowed, and improvement is being made.

Development of a 3D magnetic field sensor or 1D magnetic field sensor with a diameter of 1.0 mm or less for a built-in catheter and 0.5 mm or less for a built-in guide wire, and a magnetic field generator required for each type, combined with both A positioning system that achieves a positioning accuracy of 100 μm or less is being developed.

JP-A-2003-117004 JP-A-2010-179116 JP-A-2015-134166 Japanese Patent No. 5839527 Japanese Patent No. 6240994 Japanese Patent No. 6256962

The present invention is a three-dimensional magnetic field detection device with a built-in catheter, on the premise of a size that can be built-in, the magnetic field detection force of the three axes of the X-axis, Y-axis, and Z-axis is the same, and the S / N ratio of the output. Is to develop a three-dimensional magnetic field detection device with a high signal-to-noise ratio. According to the present invention, a positioning accuracy of 100 μm or less can be realized in combination with a magnetic field generator having a relatively simple structure.

The present inventor pays attention to the size and shape of the space for incorporating the sensor in the catheter, that is, the diameter is 1.0 mm or less and the length direction is 3 mm or less, and the element that detects the length direction (Z-axis) magnetic field is magnetic. By increasing the number of wires, the element that detects the lateral (X-axis and Y-axis) magnetic field, which has a sufficient wire length and cannot secure a sufficient magnetic wire length due to its small width, can be used. I came up with the idea of making the detection sensitivities of the three elements the same.

Since the length direction of the magnetic wire can be sufficiently long for any of the elements, a single axis having a width of 0.8 mm or less, a thickness of 0.2 mm or less, and a length of 3 mm or less can be combined by combining an elongated element and an elongated electronic circuit ASIC. First, a magnetic field sensor is manufactured, and an X-axis sensor, a Y-axis sensor, and a Z-axis sensor are arranged on three longitudinal surfaces of a rectangular pedestal having a width of 0.6 mm or less, a thickness of 0.7 mm or less, and a length of 3 mm or less. It was to be. However, the X-axis sensor and the Y-axis sensor need to be arranged on adjacent surfaces that are orthogonal to each other.
In addition, by combining an ASIC having a 3-axis switching function and an element of one axis, a magnetic field sensor of one axis with a width of 0.8 mm or less, a thickness of 0.2 mm or less, and a length of 3 mm or less is manufactured, and the other two Shaft elements are manufactured and placed on each of the three longitudinal surfaces of the rectangular parallelepiped pedestal. The three-sided element has the functions of the above-mentioned X-axis element, Y-axis element, and Z-axis element.
Further, elements having the functions of an X-axis element, a Y-axis element, and a Z-axis element are arranged on three surfaces in the longitudinal direction of the rectangular parallelepiped pedestal, and an ASIC having a three-axis switching function is arranged on one surface in the longitudinal direction. You can also do it.

According to the present invention, it is an ultra-compact 3D magnetic field detector that can be built into a catheter, and maintains the basic performance of an excellent GSR sensor such as high sensitivity, low noise, and wide measurement range, and has the same detection sensitivity of 3-axis magnetic field. In combination with an external magnetic field generator, it is possible to detect the position of the catheter tip of a living body with an accuracy of 100 μm or less and using a magnetic field generator with a simple structure. ..

It is (a) perspective view of the rectangular parallelepiped pedestal of the three-dimensional magnetic field detection device, and (b) the perspective view of the three-dimensional magnetic field detection device. It is (c) assembly sectional view of 3D magnetic field detection apparatus and (d) assembly sectional view of 3D magnetic field detection apparatus built in the catheter. It is a top view of the GSR sensor for vertical axis magnetic field detection. It is sectional drawing of A1-A2 line of the GSR sensor for vertical axis magnetic field detection. It is sectional drawing of B1-B2 line of the GSR sensor for vertical axis magnetic field detection. It is a top view of the GSR sensor for horizontal axis magnetic field detection. It is (a) perspective view and (b) assembly sectional view of the 3D magnetic field detection apparatus. It is an electronic circuit diagram of the GSR sensor which concerns on Example 1. FIG. 2 is a schematic view of (a) a perspective view and (b) an assembled cross-sectional view of the three-dimensional magnetic field detection device according to the second embodiment. It is an electronic circuit diagram of the 3D magnetic field detection apparatus which concerns on Example 2. FIG. It is a conventional three-dimensional magnetic sensor. It is a conventional one-dimensional magnetic sensor.

The three-dimensional magnetic field detection device of the present invention has a rectangular parallelepiped pedestal having a strip-shaped side surface having an aspect ratio of 2 or more and a long side length of 0.7 mm or less on the bottom surface, and a first axis on one surface of the long side of the rectangular parallelepiped pedestal. A GSR element for detecting a vertical magnetic field as a direction, and a GSR element for detecting a horizontal magnetic field as a second axis direction and a third axis direction on two other adjacent surfaces on the long side of a rectangular parallelepiped pedestal. It is composed of an ASIC-specification electronic circuit that controls three GSR elements including GSR elements in the first axis direction, the second axis direction, and the third axis direction.

This will be described with reference to FIG. 1 (a).
The rectangular parallelepiped pedestal is composed of an elongated rectangular parallelepiped having a long side / short side aspect ratio of 2 or more on the strip-shaped side surface from the perspective view of (a) the rectangular parallelepiped pedestal. The bottom surface has a long side of 0.7 mm.
One surface of the long side of the rectangular parallelepiped pedestal (meaning one surface of the side surface) in the vertical axis direction as the first axis direction, and the vertical axis in the drawing as the length direction of the rectangular parallelepiped for magnetic field detection The GSR element of is arranged.
Next, a GSR element for detecting a horizontal magnetic field, which is the width direction of a rectangular parallelepiped in the drawing, is arranged on the other two adjacent surfaces on the long side in the horizontal axis direction as the second axis direction and the third axis direction. ..
That is, the X-axis GSR element with the first axis direction as the Z-axis direction and the two axial directions of the second-axis direction and the third-axis direction arbitrarily as the X-axis direction and the Y-axis direction on the plane orthogonal to the Z-axis. , Y-axis GSR element and Z-axis GSR element are arranged, and a three-dimensional magnetic field can be detected by combining with an ASIC-specification electronic circuit that controls these three GSR elements.

There are three methods for combining the three GSR elements and the ASIC-specification electronic circuit.
For one, one GSR element is arranged on each of the three long sides of the rectangular parallelepiped pedestal, and one ASIC-specification electronic circuit having a three-axis switching function is arranged on any one surface (FIG. 1 and FIG. Figure 2).
Two, each of the three GSR elements forms an ASIC-integrated GSR sensor connected to an ASIC-specification electronic circuit, and the three ASIC-integrated GSR sensors are arranged on three surfaces on the long side of the rectangular parallelepiped pedestal, respectively. (FIGS. 7 and 8).
Three, one GSR element forms an ASIC-integrated GSR sensor connected to an ASIC-specification electronic circuit having a three-axis switching function and is arranged on one surface, and two GSR elements are arranged on two surfaces. Each is arranged and connected to the electronic circuit of the ASIC integrated GSR sensor (FIGS. 9 and 10).
First, the first method will be described, and the latter two will be left to the description of the next embodiment.

This will be described with reference to FIGS. 1 (b) , 2 (c) and 2 (d) .
The rectangular parallelepiped pedestal 31 uses a hard insulating material such as plastic or ceramic, and its size is 0.6 mm or less on the short side (width), 0.7 mm or less on the long side (thickness), and 3 mm or less on the bottom surface. ..

The substrates of the GSR element 10 for detecting the magnetic field in the vertical axis direction (hereinafter referred to as the vertical axis GSR element) and the GSR element 20 for detecting the magnetic field in the horizontal axis direction (hereinafter referred to as the horizontal axis GSR element) are rectangular pedestals. It is a rectangular and thin plate to be arranged at 31.
The vertical axis GSR element 10 comprises a magnetic wire 13 in the length direction of the substrate, a detection coil 14 orbiting the magnetic wire 13, two wire electrodes, and two coil electrodes on the substrate.
The horizontal axis GSR element 20 includes a magnetic wire 23 in the width direction of the substrate, a detection coil 24 orbiting the magnetic wire 23, two wire electrodes, and two coil electrodes on the substrate.
In the three GSR elements, the GSR element 10 is arranged on one surface of the long side of the rectangular parallelepiped pedestal 31, and the GSR element 20 is arranged on two adjacent surfaces across the long side.
The size of the GSR element is 0.8 mm or less in width, 0.2 mm or less in thickness, and 1.0 mm or less in length.

The ASIC-specification electronic circuit (ASIC1A) is arranged below the GSR element 20. The ASIC1A is connected to three GSR elements, and the electrodes 561 to 564 of the ASIC1A are connected to an external control device. The arrangement of the ASIC1A is not limited to the surface on which the GSR element 20 is arranged, and may be any surface.
The size of the ASIC is 0.8 mm or less in width, 0.2 mm or less in thickness, and 3 mm or less in length.

As described above, the three-dimensional magnetic field detection device of the present invention has an elongated rectangular parallelepiped shape having a base long side of 0.8 mm or less, a diagonal length of 1.0 mm or less, and a side surface long side of 3 mm or less. It can be built into the tip of an elongated pipe-shaped catheter (Fig. 2 (d)) .

Further, in the three-dimensional magnetic field detection device of the present invention,
The ASIC integrated GSR sensor for detecting the magnetic field in the vertical axis direction forms an amorphous magnetic wire (hereinafter referred to as magnetic wire) on the substrate film in the length direction of the substrate film composed of the insulating resist layer on the ASIC surface protective film. Two wire electrodes for applying a pulse current to the magnetic wire and two coil electrodes for measuring the coil voltage generated in the detection coil are formed by winding the detection coil around the magnetic wire. It is composed of a GSR element having a width of 0.5 mm or less, a thickness of 0.2 mm or less, and an ASIC having a length of 3 mm or less. The GSR element and the ASIC are connected via the above four electrodes.

The ASIC-integrated GSR sensor for detecting the magnetic field in the horizontal axis direction has an amorphous magnetic wire attached to a groove formed in the substrate film in the width direction of the substrate film composed of an insulating resist layer on the ASIC surface protective film, and the magnetic wire is formed. A GSR element consisting of two wire electrodes for energizing a magnetic wire with a pulse current and two coil electrodes for measuring the voltage generated in the detection coil, formed by winding a detection coil around it, and a width of 0.5 mm or less. It is composed of an ASIC having a thickness of 0.2 mm or less and a length of 3 mm or less. The GSR element and the ASIC are connected via the above four electrodes.

The three-dimensional magnetic field detection device has an ASIC-integrated GSR sensor for detecting the vertical magnetic field on one surface of the long side of the rectangular parallelepiped pedestal, and the other two surfaces of the long side for detecting the horizontal magnetic field. With the ASIC integrated GSR sensor attached, it has a rectangular parallelepiped shape with a long side of 0.8 mm or less on the bottom surface, a diagonal of 1.0 mm or less, and a side length of 3 mm or less.
The three ASIC-integrated GSR sensors are connected to an external control device by wiring cables.

Hereinafter, embodiments will be described in detail.
In the three-dimensional magnetic field detection device, one surface of the four long sides of the rectangular parallelepiped pedestal is defined as the first axis direction (hereinafter referred to as the Z axis direction), and the long sides of the remaining three long sides that are in contact with each other The two surfaces are the 2nd and 3rd axis directions (hereinafter referred to as the X-axis direction and the Y-axis direction), and the ASIC-integrated GSR sensor for detecting the magnetic field in the vertical axis direction is arranged in the Z-axis direction. An ASIC-integrated GSR sensor for detecting a magnetic field in the horizontal axis direction is arranged in the axial direction and the Y-axis direction, respectively. Adhesive is used to attach the ASIC-integrated GSR sensor to the rectangular parallelepiped pedestal. The size after attachment is 0.8 mm or less on the long side of the bottom surface, 1.0 mm or less on the diagonal line, and 3 mm or less on the side surface.
Here, the vertical axis direction magnetic field detection is the length direction of the long side surface and corresponds to the Z axis direction magnetic field detection of the three-dimensional magnetic field detection, and the horizontal axis direction magnetic field detection is the length of the long side surface. It is the width direction orthogonal to the vertical direction and corresponds to the X-axis direction magnetic field detection and the Y-axis direction magnetic field detection among the three-dimensional magnetic field detections.

Further, the three-dimensional magnetic field detection device has a strip shape having an aspect ratio of the length and width of the GSR sensor of 2 or more. Therefore, the rectangular parallelepiped pedestal on which the three strip-shaped GSR sensors having an aspect ratio of 2 or more are arranged is also made into a strip-shaped strip having an aspect ratio of 2 or more.

The rectangular parallelepiped pedestal uses a hard insulating material such as plastic or ceramic, and its size is 0.6 mm or less in width, 0.7 mm or less in thickness, and 3 mm or less in length. Corresponding to the preferred size of the ASIC, width 0.2 mm-0.5 mm, thickness 0.08 mm-0.12 mm, length 1 mm-1.6 mm, preferably width 0.36 mm-0.5 mm, The thickness is 0.28 mm to 0.48 mm, and the length is 1 mm to 1.6 mm.

The ASIC integrated GSR sensor for detecting the magnetic field in the vertical axis direction (hereinafter referred to as the vertical axis GSR sensor) is an integrated circuit for a specific application having a width of 0.8 mm or less, a thickness of 0.2 mm or less, and a length of 3 mm or less. A substrate film composed of an ASIC) and an insulating resist layer (hereinafter referred to as a resist layer) having a thickness capable of functioning as a substrate of a GSR element is formed on the insulating protective film on the surface of the ASIC, and is formed on the substrate film. A vertical axis GSR element including a magnetic wire in the length direction of an ASIC, a detection coil that orbits the magnetic wire, and an electrode is integrally molded. The vertical axis GSR element is connected to the ASIC via a wire electrode and a coil electrode of the vertical axis GSR element.

The length of the amorphous magnetic wire is longer than the width of the ASIC, and the number of the amorphous magnetic wires is one or two. A plurality of electrodes for power supply and signal communication with an external computer are installed at the other end of the ASIC in the length direction. An electric wire is inserted from the outside through a catheter tube, and the electric wire is connected to an ASIC electrode to supply power and communicate signals.

The ASIC integrated GSR sensor for detecting the magnetic field in the horizontal axis direction (hereinafter referred to as the horizontal axis GSR sensor) includes an ASIC having a width of 0.8 mm or less, a thickness of 0.2 mm or less, and a length of 3 mm or less, and an ASIC surface surface. A substrate film made of a resist layer having a thickness capable of functioning as a substrate for a GSR element is formed on the insulating protective film, and a detection coil and a detection coil that circulate the magnetic wire in the width direction of the ASIC and the magnetic wire on the substrate film. A horizontal axis GSR element composed of electrodes is integrally molded. The horizontal axis GSR element is connected to the ASIC via a wire electrode and a coil electrode of the horizontal axis GSR element.

The length of the amorphous magnetic wire corresponds to the width of the ASIC, and the number of the amorphous magnetic wire is 2 or 4. A horizontal axis GSR sensor composed of a short horizontal axis GSR element requires the length of the horizontal axis GSR element corresponding to the length of the vertical axis GSR element in order to obtain the same magnetic field detection force as the vertical axis GSR sensor. Because.

Similar to the vertical axis GSR sensor, a plurality of electrodes for power supply and signal communication with an external computer are installed at the other end of the ASIC in the length direction. An electric wire is inserted from the outside through a catheter tube, and the electric wire is connected to an ASIC electrode to supply power and communicate signals.

A GSR sensor in which a GSR element (both a vertical axis GSR element and a horizontal axis GSR element) and an ASIC are integrally molded can be made ultra-thin and ultra-compact, and this one vertical axis GSR sensor and two It is possible to achieve ultra-miniaturization of the rectangular parallelepiped of the three-dimensional magnetic field detection device in which the combination of the horizontal axis GSR sensors is attached to the rectangular parallelepiped pedestal. This ultra-miniaturized three-dimensional magnetic field detector is ideal for incorporation into the tip of a catheter tube.

The GSR element is composed of an amorphous magnetic wire that is a magnetic sensor, a detection coil that circulates around the magnetic wire, terminals at both ends of the magnetic wire and the detection coil, an electrode that connects the terminals at both ends and ASIC, and wiring between the terminals and the electrodes. Has been done.

The amorphous magnetic wire 13 is a CoFeSiB alloy having a diameter of 15 μm or less, preferably 10 μm or less. The periphery of the magnetic wire 13 is preferably coated with an insulating material, for example, an insulating glass material. Insulation between the magnetic wire 13 and the detection coil 14 is easy, and the gap between the two can be reduced to reduce the inner diameter of the coil.

The inner diameter of the detection coil is 30 μm or less, preferably 15 μm or less. Sensitivity is improved by reducing the inner diameter of the coil. The coil pitch is 5 μm or less, preferably 3 μm or less. As a result, the number of coil turns per unit length can be increased, the sensitivity can be improved, and the magnetic field detection element can be shortened to reduce the size.

The electronic circuit of the GSR sensor is based on the electronic circuit disclosed by the present inventor in Patent Document 4.
The basic circuit includes a pulse transmitter (pulse transmitter) and a signal processing circuit. The signal processing circuit includes a buffer circuit, a detection timing adjustment circuit, an electronic switch, a sample hold circuit, and an amplifier. A high-frequency pulse current equivalent to 2 GHz generated by the pulse oscillation circuit is supplied to the magnetic wire of the GSR element. When a pulse current is applied, the electron spin on the surface of the magnetic wire rotates at high speed, and a voltage corresponding to the external magnetic field is generated in the detection coil. This output voltage is sample-held and detected by the amplifier. The pulse frequency referred to here is conveniently defined as the pulse frequency, with the period being four times the "falling down" time Δt of the pulse current and its reciprocal.

The output voltage of the detection coil is held as the capacitor voltage of the sample hold circuit by switching (on-off) the electronic switch in a short time at a predetermined timing from the fall of the pulse current by the detection timing adjustment circuit, and this sampling The voltage is amplified by the amplifier and output.

After that, it is AD-converted, data is stored and corrected by the built-in small CPU, and transferred to an external control device.
At this time, the control device controls the three-dimensional magnetic field detection device, but two power lines for supplying power from the outside and two signals for transmitting signals to the outside and controlling the GSR sensor from the outside. The GSR sensor is controlled by a total of four electric wires consisting of wires.

Therefore, the three-dimensional magnetic field detection device includes a total of six wires consisting of two signal lines for each of the ASIC-integrated GSR sensors and a total of six wires consisting of two power lines for each of the ASIC-integrated GSR sensors. A total of 12 wires are connected to the external control device.
In addition, the three-dimensional magnetic field detection device has a common power supply line for the ASIC-integrated GSR sensor, and has eight wirings, including two power supply lines and two signal lines for each of the two ASIC-integrated GSR sensors, for a total of six wires. Is connected to an external control device.
By reducing the number of wires, the wire connecting the sensor built in the catheter and the external control device can be miniaturized. This improves application to small diameter catheters. Further, in terms of strength, the number of connection points with the leader wire is reduced, so that failure is less likely to occur.

The size of the ASIC is 0.8 mm or less in width, 0.2 mm or less in thickness, and 3 mm or less in length. Preferably, the width is 0.2 mm to 0.4 mm, the thickness is 0.08 mm to 0.12 mm, and the length is 1 mm to 1.6 mm.

On the upper surface of the ASIC, four electrodes for connecting to the GSR element are arranged at both ends in the width direction of the upper surface. The electrodes of the ASIC and the electrodes of the GSR element are connected via a through hole provided in the resist layer. The through hole portion is formed by a plating or vapor deposition process. As the material, a good conductive material such as gold or copper is used.

Four electrodes for external connection are installed at one end of the ASIC in the longitudinal direction.
These electrodes and the external device are connected by using a flexible electric wire in which four wires are bundled. The four flexible wires and the four electrodes of the ASIC are joined by a solder joining method. Three flexible electric wires are bundled to connect an internal 3D magnetic sensor and an external computer.

The vertical axis GSR sensor (Z-axis GSR sensor) has a sensitivity of 70 mV / G to 300 mV / G, σ noise of 20 μV to 30 μV, an S / N ratio of 1000 to 3000 when the magnetic field strength is 1 G, and a measurement range of 5 G to. 20G, the bandwidth of the analog circuit is 50KHz, and the ODR of the digital output is 1KHz. The linearity is 0.2% with respect to the full scale, and there is no hysteresis.
It was confirmed that the characteristics of the horizontal axis GSR sensor (X-axis GSR sensor and Y-axis GSR sensor) are the same, and the detection sensitivities of the three axes can be adjusted in the same manner.
The three-dimensional magnetic field detection device has an ASIC-integrated GSR sensor for detecting the vertical magnetic field on one surface of the long side of the rectangular parallelepiped pedestal, and the other two surfaces of the long side for detecting the horizontal magnetic field. With the ASIC integrated GSR sensor attached, it has a rectangular parallelepiped shape with a long side of 0.8 mm or less on the bottom surface, a diagonal of 1.0 mm or less, and a side length of 3 mm or less.

Further, in the three-dimensional magnetic field detection device of the present invention, any one of the GSR elements in the first axis direction, the second axis direction, or the third axis direction is integrated with an ASIC having a three-axis switching function. A 3-axis switching ASIC integrated GSR sensor with a width of 0.8 mm, a thickness of 0.2 mm, and a length of 3 mm or less is formed, and the other two GSR elements are connected to the 3-axis switching ASIC integrated GSR sensor on a rectangular pedestal. However, the ASIC has a width of 0.8 mm, a thickness of 0.8 mm, and a length of 3 mm or less, which are connected to an external control device by a wiring cable.

This three-dimensional magnetic field detection device is the third method, and uses an ASIC having a three-axis switching function, and a total of four wires consisting of two power lines and two signal lines of the ASIC integrated GSR sensor. Is connected to an external control device.
The three ASICs can be simplified into one, and the wiring for connecting to an external control device can be reduced.
The three-dimensional magnetic field detection device has an ASIC-integrated GSR sensor for detecting the vertical magnetic field on one surface of the long side of the rectangular parallelepiped pedestal, and the other two surfaces of the long side for detecting the horizontal magnetic field. With the ASIC integrated GSR sensor attached, it has a rectangular parallelepiped shape with a long side of 0.8 mm or less on the bottom surface, a diagonal of 1.0 mm or less, and a side length of 3 mm or less.

In the case of a uniaxial magnetic sensor, the external magnetic field generator requires three gradient magnetic field generators and three uniform magnetic field generators, which are arranged in a complicated and three-dimensional manner. There was a drawback that the treatment space for treatment was narrowed. However, by incorporating the three-dimensional magnetic field detection device in the tip of the catheter, accurate positioning is possible with only two uniform magnetic field generators and one gradient magnetic field generator. Further, in a system using a 1-axis magnetic sensor, in principle, there is a direction in which the magnetic field cannot be detected, that is, a singular point, but by using the 3-axis magnetic sensor, the magnetic field can be detected in all directions. Therefore, the treatment space can be widened, the singularity disappears, and the problem of the system using the uniaxial magnetic sensor can be solved.

[Example 1]
Example 1 is one of an ASIC integrated GSR sensor for detecting a vertical magnetic field for detecting a Z-axis magnetic field (hereinafter referred to as a vertical GSR sensor), and a horizontal one for detecting an X-axis magnetic field and detecting a Y-axis magnetic field. A total of three GSR sensors consisting of two axial ASIC integrated GSR sensors (hereinafter referred to as horizontal axis GSR sensors) are arranged on three surfaces of a rectangular pedestal, and are arranged in the Z-axis direction, the X-axis direction, and Y. The present invention relates to a three-axis magnetic field detection device that accurately detects a three-axis magnetic field composed of axial directions.

The plan view of the vertical axis GSR sensor according to the first embodiment is shown in FIG. 3, the cross-sectional view of the A1-A line in the same figure is shown in FIG. 4, and the cross-sectional view of the B1-B2 line in the same figure is shown in FIG. A plan view of the horizontal axis GSR sensor is shown in FIG. FIG. 7 shows a schematic view of (a) a perspective view and (b) a schematic view of an assembled cross-sectional view of a three-dimensional magnetic field detection device in which one vertical axis GSR sensor and two horizontal axis GSR sensors are combined. The electronic circuit diagram is shown in FIG. The first embodiment will be described with reference to these drawings.

As shown in FIGS. 3 to 5, the vertical axis GSR sensor 1 has a width of 0.4 mm, a thickness of 0.1 mm, and a length of 1.4 mm on an insulating protective film of ASIC1A having a width of 0.4 mm and a length of 0.4 mm. A vertical axis GSR element 10 having a size of 0.8 mm is formed. The substrate film 11 of the vertical axis GSR element 10 is formed of an insulating resist layer (hereinafter referred to as a resist layer) having a thickness of 7 μm on the insulating protective film of ASIC1A by three-dimensional photolithography technology, and functions as an element substrate. Then, in the substrate film 11, one inverted trapezoidal groove 12 having a width of 14 μm and a depth of 7 μm is formed in the central portion of the substrate film 11 in the length direction of the ASIC 1A (horizontal direction in FIG. 1). ..

A concave lower coil 144 is formed along the surfaces (bottom surface and side surface) of the groove 12 and both sides of the groove 12. On the lower coil 144, one magnetic wire 13 having an insulating glass coating having a diameter of 10 μm and a length of 0.6 mm is installed, and an insulating resist 111 is applied around the magnetic wire 13 to form a convex upper coil 143. It is formed. The convex upper coil 143 and the concave lower coil 144 are electrically joined via a joint portion 145. In this way, the spiral detection coil 14 orbits the magnetic wire 13. The coil inner diameter of the detection coil 14 is 15 μm, and the coil pitch is 5 μm.

At both ends of the magnetic wire 13, the glass of the insulating coating material is removed to form terminals 131 that can be electrically connected by metal vapor deposition. Further, a wire electrode 15 is formed via a wire electrode connecting line 132 for electrical connection with the ASIC at both ends in the width direction of the ASIC.
The detection coil 14 also forms the coil terminal 141, the coil electrode connecting wire 142, and the coil electrode 16.
This makes an electrical connection with the ASIC.

At the other end of the ASIC1A (the right end in FIG. 3), there are two power supply electrodes consisting of a power supply electrode 491 and a ground electrode 494, and a communication electrode 2 composed of a command input electrode 492 and an output electrode 493 for signal communication with an external computer. A total of four electrodes are installed.
An electric wire is inserted from the outside through a catheter tube, and the electric wire is connected to an electrode of ASIC1A to supply power and exchange signals.

As shown in FIG. 6, the horizontal axis GSR sensor 1 has a width of 0.4 mm, a thickness of 0.1 mm, and a length of 1.4 mm at one end on the insulating protective coating of the ASIC 1A. A horizontal axis GSR element 20 having a size of 0.8 mm is formed. The substrate film 21 of the horizontal axis GSR element 20 is formed of an insulating resist layer (hereinafter referred to as a resist layer) having a thickness of 7 μm on the insulating protective film of ASIC1A by three-dimensional photolithography technology, and functions as an element substrate.
Then, two inverted trapezoidal grooves 22 having a width of 14 μm and a depth of 7 μm are formed in the substrate film 21 in the width direction of the ASIC 1A (vertical direction in FIG. 4) at the center of the substrate film 21.
The cross-sectional view of FIG. 6 is the same as that of FIGS. 4 and 5 of the vertical axis GSR sensor.

A concave lower coil is formed along the surfaces (bottom surface and side surface) of the two grooves 22 and both sides of the groove 22. On the lower coil, one magnetic wire 23L and one magnetic wire 24R each having an insulating glass coating having a diameter of 10 μm and a length of 0.4 mm are installed, and an insulating resist is applied around them to form a convex shape. A coil is formed. The convex upper coil and the concave lower coil are electrically joined via a joint portion. In this way, both the spiral detection coil 24L that orbits the magnetic wire 23L and the magnetic wire 23R, the detection coil 24L that becomes the detection coil 24R, and the detection coil 25R (hereinafter, referred to as the detection coil 24) connect the coil-to-coil connecting wire 244. It is connected by a coil-to-coil terminal 243 via the coil terminal 243.
The coil inner diameter of the detection coil 24 is 15 μm, and the coil pitch is 5 μm.

At both ends of both the magnetic wire 23L and the magnetic wire 23R (hereinafter referred to as the magnetic wire 23), wire terminals 231 and wire-to-wire terminals 233 that can be electrically connected by removing the glass of the insulating coating material by metal vapor deposition are provided. Form. Both the magnetic wire 23L and the magnetic wire 23R are connected by a wire-to-wire terminal 233 and a wire-to-wire connecting line 234, respectively.
Further, a wire electrode 25 is formed via a wire electrode connecting line 232 for electrical connection with the ASIC at both ends in the width direction of the ASIC.
The coil terminal 241, the coil electrode connecting wire 242, and the coil electrode 26 are also formed for both the detection coil 24L and the detection coil 24R (hereinafter referred to as the detection coil 24).
This makes an electrical connection with the ASIC.

At the other end of the ASIC1A (the right end in FIG. 3), there are two power supply electrodes consisting of a power supply electrode 491 and a ground electrode 494, and a communication electrode 2 composed of a command input electrode 492 and an output electrode 493 for signal communication with an external computer. A total of four electrodes are installed.
An electric wire is inserted from the outside through a catheter tube, and the electric wire is connected to an electrode of ASIC1A to supply power and exchange signals.

As the electronic circuit of the GSR sensor, the vertical axis GSR sensor and the horizontal axis GSR sensor are the same as the electronic circuit disclosed in Patent Document 4 described above. Therefore, the electronic circuit 4 of the vertical axis GSR sensor will be described as an example.
The electronic circuit 4 includes a pulse transmitter circuit 41 (pulse transmitter 41) and a signal processing circuit 42. The signal processing circuit includes a buffer circuit 43, a detection timing adjustment circuit 44, an electronic switch 45, a sample hold circuit 46, and an amplifier 47.
A high-frequency pulse current equivalent to 2 GHz generated by the pulse oscillation circuit 41 is supplied to the magnetic wire 12 of the GSR element 10. When a pulse current is applied, the electron spin on the surface of the magnetic wire rotates at high speed, and a voltage corresponding to an external magnetic field is generated in the detection coil 13. This voltage is sample-held by the sample-hold circuit 46 and detected by the amplifier 47.
The pulse frequency referred to here is conveniently defined as the pulse frequency, with the period being four times the "falling down" time Δt of the pulse current and its reciprocal.

The output voltage of the coil is held as the capacitor voltage of the sample hold circuit 46 by switching (on-off) the electronic switch 45 in a short time at a predetermined timing from the fall of the pulse current by the detection timing adjustment circuit 44. This sampling voltage is amplified by the amplifier 47 and output.

After that, it is AD-converted by the AD converter 481, data is stored and corrected by the built-in small CPU in the arithmetic circuit 482, and transferred to an external computer via the communication circuit 483. At this time, the three-dimensional magnetic field detection device is controlled by the control device, but from the outside, two power lines for power supply, a signal line for signal transmission to the outside, and a sensor from the outside are controlled. The sensor is controlled by a total of four electric wires.

The size of ASIC1A consists of a width of 0.4 mm, a thickness of 0.1 mm, and a length of 1.4 mm.
On the upper surface of the ASIC 1A, four electrodes for connecting to the GSR element 10, that is, two wire electrodes 15A and two coil electrodes 16A are arranged at both ends in the width direction of the upper surface. The wire electrode 15A and coil 16A on the ASIC side and the wire electrode 15 and coil electrode 16 of the GSR element are connected via through holes 151 and 161 provided in the substrate film 11. The through-hole portion is made of copper by a plating method.

Four electrodes 491, 492, 493, 494 for external connection are arranged at one end of the ASIC1A in the length direction.
These electrodes and the external device are connected by using a flexible electric wire in which four wires are bundled. The four flexible wires and the four electrodes of ASIC1A are joined by a solder joining method. Three flexible electric wires are bundled to connect an internal three-dimensional magnetic field detection device and an external computer.

The rectangular parallelepiped pedestal 31 is made of ceramic and has a width of 0.3 mm, a thickness of 0.4 mm, and a length of 1.4 mm. The horizontal axis GSR sensor 2 is used as an X-axis GSR sensor, the horizontal axis GSR sensor 2 is used as a Y-axis GSR sensor, and the vertical axis GSR sensor 1 is used as a Z-axis GSR on three of the four longitudinal surfaces of the rectangular parallelepiped pedestal 31. Place each as a sensor. However, the X-axis GSR sensor and the Y-axis GSR sensor are arranged on adjacent surfaces that are orthogonal to each other. An adhesive is used to attach each sensor to the rectangular parallelepiped pedestal 31 (FIG. 7).
The size of the three-dimensional magnetic field detection device produced in this way is 0.5 mm in width and 0.5 mm in thickness.
It can be incorporated into a catheter having a length of 1.4 mm and an inner diameter of 1.0 mm (FIGS. 7 (b) and 1 (d)).

The Z-axis GSR sensor has a sensitivity of 100 mV / G, σ noise of 25 μV (0.25 mG in terms of magnetic field), an S / N ratio of 1200 when the magnetic field strength is 1 G, a measurement range of 5 G, and an analog circuit bandwidth of 50 KHz. The digital output ODR is 1 KHz. The linearity was 0.2% with respect to the full scale, and there was no hysteresis. The characteristics of the X-axis GSR sensor and the Y-axis GSR sensor were the same, and the detection sensitivities of the three axes could be adjusted to be the same.

Two uniform magnetic field generators and one gradient magnetic field generator are used as external magnetic field generators. The gradient of the magnetic field is 0.2 mG / μm. The resolution of the spatial position of the product of the present invention is about 7 μm because the noise is 1.5 mG (6σ). The positioning accuracy is considered to be about 70 μm in consideration of the manufacturing variation between the coils, the influence of temperature, the influence of the external magnetic field, the error of the measurement position, etc. in the magnetic field space region having a radius of 10 cm.

[Example 2]
In the second embodiment, three GSR elements having the same structure as that of the first embodiment are modified into one ASIC (referred to as ASIC2A) in which the three elements can be operated by the changeover switch 53 to obtain the above-mentioned three-dimensional magnetic field detection device. Is.
FIG. 9 shows a schematic view of (a) a perspective view and (b) an assembled cross-sectional view of the three-dimensional magnetic field detection device, and FIG. 10 shows an electronic circuit.
First, a 3-axis switching ASIC integrated GSR sensor 2 (from the X-axis GSR element 20) integrated with an ASIC having a 3-axis switching function with one surface (upper surface in FIG. 9) of the rectangular parallelepiped pedestal 31 as the second axis direction. Sensor) is installed.
Next, the Y-axis GSR element 20 in the third axis direction and the Y-axis GSR element 20 in the third axis direction are placed on both side surfaces (the back surface and the front surface in FIG. 9) via the long side in the longitudinal direction of the 3-axis switching ASIC integrated GSR sensor 2. The Z-axis GSR elements 10 in the first axis direction are attached respectively.
The Y-axis GSR element 20 and the Z-axis GSR element 10 are wired to be connected to the 3-axis switching ASIC integrated GSR sensor 2 on the rectangular parallelepiped pedestal 31.
In addition, the ASIC is connected to an external microcomputer (control device) with a wiring cable.
The size and performance of this three-dimensional magnetic field detection device are the same as those in the first embodiment.

The ultra-small three-dimensional magnetic sensor of the present invention is expected as a sensor attached to the tip of a medical catheter and the tip portion of the tip portion determines a three-dimensional position in a magnetic field space.

1: Vertical axis GSR sensor, 1A: (Vertical axis) ASIC for GSR sensor,
10: Vertical axis GSR element, 11: Substrate film (insulating resist layer), 111: Insulating resist, 12: Groove, 13: Magnetic wire, 131: Wire terminal, 132: Wire electrode connecting wire, 14: Detection coil, 141: Coil terminal, 142: Coil electrode connecting wire, 143: Upper coil, 144: Lower coil, 145: Joint part, 15: Wire electrode, 15A: ASIC side wire electrode, 151: Through hole (wire electrode and ASIC side) (For connection with wire electrode), 16: Coil electrode, 16A: Coil electrode on ASIC side, 161: Through hole (for connection between coil electrode and coil electrode on ASIC side), 491: Power supply electrode, 492: Command input electrode , 183: Output electrode, 494: Earth electrode,
2: Horizontal axis GSR sensor, 2A: (Horizontal axis) ASIC for GSR sensor
20: Horizontal axis GSR element, 21: Substrate film (insulating resist layer), 22: Groove, 23: Magnetic wire (both 23L and 23R) 23L: Magnetic wire (left side), 23R: Magnetic wire (right side) ), 231: Wire terminal, 232: Wire electrode connecting line, 233: Wire-to-wire terminal, 234: Wire-to-wire connecting line, 24: Detection coil (both 24L and 24R) 24L: Detection coil (left side), 24R : Detection coil (right side), 241: Coil terminal, 242: Coil electrode connection line, 243: Inter-coil terminal, 244: Inter-coil connection line, 25: Wire electrode, 26: Coil electrode,
3; 3D magnetic field detector, 31: rectangular parallelepiped pedestal

4: Electronic circuit of GSR sensor 41: Pulse oscillation circuit (pulse transmitter), 42: Signal processing circuit, 43: Buffer circuit, 44: Detection timing adjustment circuit, 45: Electronic switch, 46: Sample hold circuit, 47: Amplifier , 48: Digital communication circuit, 481: AD converter, 482: Arithmetic circuit, 483: Communication circuit, 49: External connection electrode, 491: Power supply electrode, 492: Command input electrode, 493: Output electrode, 494: Earth electrode,
5: Electronic circuit of GSR sensor for 3-axis switching,
10: Z-axis GSR element, 13: magnetic wire, 14: detection coil, 20: X-axis GSR element and Y-axis GSR element, 23: magnetic wire, 24: detection coil, 51: pulse oscillator circuit (pulse transmitter), 52: Detection timing adjustment circuit, 53: Changeover switch, 54: Signal processing circuit, 55: Digital / communication circuit, 551: AD converter, 552: Arithmetic circuit, 535: Communication circuit, 56: External connection electrode, 561: Power supply Supply electrode, 562: Command input electrode, 563: Output electrode, 564: Earth electrode,

Claims (3)

A rectangular parallelepiped pedestal consisting of a strip-shaped side surface with an aspect ratio of 2 or more and a long side length of 0.7 mm or less on the bottom surface.
On one surface of the long side of the rectangular parallelepiped pedestal, a GSR element for detecting a magnetic field in the vertical axis direction as the first axial direction, and
On the other two adjacent surfaces on the long side of the rectangular parallelepiped pedestal, a GSR element for detecting a magnetic field in the horizontal axis direction in the second axis direction and the third axis direction,
In a three-dimensional magnetic field detection device including an ASIC-specification electronic circuit that controls three GSR elements including the GSR elements in the first axial direction, the second axial direction, and the third axial direction.
The GSR element for detecting the magnetic field in the vertical axis direction is
An amorphous magnetic wire (hereinafter referred to as a magnetic wire) is placed in a groove formed in the length direction of the substrate film on a substrate film composed of an insulating resist layer formed on an ASIC surface protective film, and the magnetic wire is formed. A detection coil is formed around the magnetic wire, and two wire electrodes for applying a pulse current to the magnetic wire and two coil electrodes for measuring the coil voltage generated in the detection coil are provided.
The ASIC having a width of 0.8 mm or less, a thickness of 0.2 mm or less, and a length of 3 mm or less is connected to the GSR element for detecting the magnetic field in the vertical axis direction via the four electrodes for detecting the magnetic field in the vertical axis direction. Formed an ASIC integrated GSR sensor
The GSR element for detecting the magnetic field in the horizontal axis direction is
The magnetic wire is placed in a groove formed in the width direction of the substrate film on a substrate film made of an insulating resist layer formed on the ASIC surface protective film, and a detection coil is formed around the magnetic wire. It is provided with two wire electrodes for energizing a magnetic wire with a pulse current and two coil electrodes for measuring a voltage generated in the detection coil.
The ASIC having a width of 0.8 mm or less, a thickness of 0.2 mm or less, and a length of 3 mm or less is connected to the GSR element for horizontal axis magnetic field detection via the four electrodes for horizontal axis direction magnetic field detection. Forming an ASIC integrated GSR sensor,
The ASIC integrated GSR sensor for detecting the vertical magnetic field is on one surface of the long side of the rectangular parallelepiped pedestal, and the ASIC integrated GSR sensor for detecting the horizontal magnetic field is on the other two adjacent surfaces of the long side. It consists of a rectangular parallelepiped with a long side of 0.8 mm or less on the bottom surface, a diagonal of 1.0 mm or less, and a side length of 3 mm or less with the GSR sensor attached.
The three ASICs are three-dimensional magnetic field detection devices, each of which is connected to an external control device by a wiring cable. In claim 1,
A total of 6 wires consisting of 2 signal lines for each of the ASIC integrated GSR sensor and 2 or 6 wires consisting of the power supply line for the ASIC integrated GSR sensor, for a total of 8 or 12 wires. A three-dimensional magnetic field detection device characterized by being connected to an external control device. In claim 1,
Any one of the GSR elements in the 1st axis direction, the 2nd axis direction, or the 3rd axis direction is
A 3-axis switching ASIC integrated GSR sensor with a width of 0.8 mm, a thickness of 0.2 mm, and a length of 3 mm or less, which is integrated with an ASIC having a 3-axis switching function, is formed.
The other two GSR elements are connected to the 3-axis switching ASIC integrated GSR sensor on the rectangular parallelepiped pedestal.
The ASIC is characterized by having a rectangular parallelepiped shape having a long side of 0.8 mm or less, a diagonal line of 1.0 mm or less, and a side surface length of 3 mm or less, which is connected to an external control device by a wiring cable. Dimensional magnetic field detector.

Images