WO2023167051A1 - METHOD FOR PRODUCING Cr-Ni-BASED STAINLESS MAGNET FOR GUIDE WIRES, SMART GUIDE WIRE, GUIDE WIRE OPERATION SYSTEM, AND GUIDE WIRE OPERATION ROBOT SYSTEM - Google Patents

Abstract

[Problem] The present invention provides a technique for enabling a robot operation by incorporating a sensor in a guide wire, facilitating a treatment operation and reducing the time of irradiation by X-ray. [Solution] The position and orientation of a tip part of a guide wire are calculated using a Cr-Ni-based stainless magnet positioned at the tip part and an external magnetic vector sensor grid system. The contact pressure applied to the tip part is measured by attaching a strain gauge to a wire. The torque on the driver side and the feed quantity and rotation amount of the wire are measured by installing a torque sensor, a torquer rotation quantity measuring sensor and an azimuth meter in a driver. The treatment with the guide wire can be automatically controlled using these measurement values.

Description

Method for manufacturing Cr-Ni stainless steel magnet for guide wire, smart guide wire, guide wire operating system, and guide wire operating robot system

The present invention includes an in vivo sensor, a built-in guide wire with a magnet manufactured by a method for manufacturing a Cr—Ni stainless steel magnet, a magnetic vector sensor grid placed outside the patient's body (ex vivo), and various sensor data. The present invention relates to a smart guide wire, a guide wire manipulation system, and a guide wire manipulation robot system comprising a sensor data processing device and its display device obtained from, etc.

Catheterization is an operation in which a catheter is inserted directly into the patient's body instead of surgery, and the burden on the patient is light. The treating doctor identifies the diseased area on the blood vessel map created by X-rays, and guides the catheter toward that position. The treating doctor manipulates the catheter while observing the tip position of the catheter on the blood vessel map with X-rays.
In this treatment, the burden on the patient's body due to long-time irradiation of X-rays and administration of a contrast agent is a problem. In addition, X-ray exposure of treating doctors and the like is also a problem. Therefore, the technological development of robot therapy is being actively pursued. For example, a magnet or sensor is inserted into the patient's body (blood vessel) along with a catheter, and a magnetic sensor or the like is placed outside the patient's body (body), and the treating doctor treats the patient while looking at a display device (display). (Patent Document 1, Patent Document 2).

On the other hand, since guidewires have very small diameters of 0.3 mm to 1 mm, no autonomous guidance system has been developed, such as catheters containing magnets. This is because the diameter of the guidewire is very small, and if a smaller magnet is built into it, the magnet will produce a very small magnetic field, which is difficult to detect with a magnetic field sensor mounted outside the patient's body. there were. Furthermore, it is required to position the tip of a small guide wire with an accuracy of ±0.1 mm or less, and it is almost impossible to attach a magnet to the tip of the guide wire and detect the magnetic field to position the tip. was thought to be

In addition, since the guide wire may pierce the blood vessel and cause bleeding trouble, it is also required to determine the contact force applied to the tip of the guide wire. Small and highly sensitive strain gauges have been researched and developed using semiconductor methods and stress impedance sensors (hereinafter referred to as SI sensors) (Non-Patent Document 1), but have not yet been successfully developed.

Furthermore, the tip of the guide wire is controlled by the torque applied to the driver at hand and the amount of rotation of the torquer, but the current situation is that the operation depends on the experience and intuition of the treating doctor. Therefore, many years of experience and advanced knowledge are required, which is an obstacle to the training of treating doctors. There is a need to quantify and visualize the control parameters on the driver side, and to advance the quantification and visualization of the movement of the tip of the wire and the contact pressure with the blood vessel corresponding to it, to make the surgery easier for the treating doctor. .

Using these sensors, that is, specifying the position of the tip of the wire, and furthermore, by quantifying and visualizing operation data such as the contact pressure between the tip of the wire and the blood vessel, torque on the driver side, etc., we assist the treating doctor and perform surgery. It is expected to facilitate operation, reduce dependence on X-ray images, and shorten X-ray irradiation time. Furthermore, it is expected to establish a robot operation system in which the treating physician instructs the movement position of the wire tip position and automatically controls the guide wire tip accordingly.

US 6,618,612 US2004/0068178

A first object of the present invention is to
A smart guide wire consisting of a guide wire consisting of a wire tip to be inserted into the living body (inside a blood vessel), a driver part, and a wire connecting part that connects the two, and a data processing device outside the patient's body that operates the guide wire,
It is a particularly difficult development task to develop a device that includes a magnet at the wire tip of a guide wire, attaches a magnetic field sensor to the outside of the body, and detects the in vivo position of the magnet. This is because there is a contradictory characteristic between the size of the magnet and the positional accuracy. In the present invention, this problem is solved by modifying the Cr--Ni stainless steel member at the tip of the wire itself into a magnet.
Furthermore, a strain gauge is attached to the tip of the wire, and a device for measuring the load applied to the tip is provided,
The driver unit is equipped with a torque sensor, torquer rotation measurement device, driver rotation angle detection sensor, and rotation speed detection sensor.
a magnetic vector sensor grid for placement outside the patient's body and a position sensor data processor for calculating the position and orientation of the wire tip using data from the magnetic vector sensor grid;
A stress sensor data processing device that calculates the contact pressure and bending stress of the wire tip, the torque and amount of rotation of the driver part, and the rotation direction and rotation speed of the driver, a rotation (torque, rotation amount) sensor data processing device, and a rotation detection ( The purpose is to develop a sensor-embedded smart guidewire consisting of a sensor data processing device and a display device that displays the calculated measured values.

In order to solve the first problem of the present invention, it is necessary to develop the following five new elemental technologies.
The first issue in the development of new elemental technology is to focus on the fact that the guide wire is made of Cr-Ni stainless steel, which is a semi-hard magnetic material. After reforming to , part of the tip is magnetized to form a Cr-Ni stainless steel magnet, and the magnetic field emitted therefrom is detected by a magnetic vector sensor grid placed outside the patient's body, and the magnetic vector sensor grid The goal is to develop a smart guidewire consisting of a position sensor data processor that uses data to calculate the position and orientation of the wire tip and a display that displays the calculated position and orientation values.

In other words, although the wire tip of the guide wire is made of Cr—Ni stainless steel, the hard magnetic properties are improved, and the magnetic properties are obtained by magnetizing only a part of the tip and the semi-hard magnetic material over the entire length of the wire. As a permanent magnet, there has been a demand for the development of a composite magnetic material that combines both properties.

Furthermore, in order to ensure the target positioning accuracy of 0.1 mm or less when the distance between the tip and the center of the grid is 5 cm or less, and the azimuth accuracy of 1 degree or less, the Cr—Ni stainless steel magnet must be 1×10 Development of a magnet with a magnetic moment of ^-9 Wbm to 20×10 ^-9 Wbm or more and development of a magnetic vector sensor with a magnetic detection power of 10 nT or less have been desired.
Strictly speaking, the positional accuracy greatly depends on the depth of the tip inside the body. Therefore, considering the treatment depth of the tip of the guidewire, the strength of the tip magnet and the detection power of the magnetic sensor are combined, preferably 1 mm or less. must ensure an accuracy of 0.1 mm or less.

The second issue in the development of new elemental technology is to develop an ultra-compact strain gauge with a width of 0.2mm and a length of 3mm, and a highly sensitive strain gauge with a gauge factor of 1000 or more. It is possible to detect the contact pressure and bending stress of the tip of the wire by installing it on the part of the wire.
The third issue in the development of new elemental technology is to develop a torque sensor using the strain gauge developed above.

The fourth issue in the development of new elemental technology is to attach a torque sensor to the handle and torquer of the driver part, measure the force applied to the wire tip rotation with the torque sensor on the handle, and load the wire insertion with the torque applied to the torquer. The pressing force applied is measured, the amount of relative rotation between the handle and the torquer is measured by a rotation amount measuring device, and the feed amount of the wire is calculated from the amount of rotation. For this purpose, we are developing a small and highly sensitive twist gauge and a small and small rotational amount measuring device capable of detecting minute rotation angles.

The fifth issue in the development of new elemental technology is to attach a motion sensor to the steering wheel of the driver to detect the direction of rotation, the amount of rotation, and the rotation speed of the steering wheel. Therefore, the azimuth accuracy of the electronic compass is improved from 5 degrees to about 0.1 degrees, and the azimuth accuracy of the composite sensor that combines the electronic compass, 3-axis acceleration sensor and gyro sensor is reduced from about 10 degrees to 1 degree or less. It is to improve.

The second subject of the present invention is
A smart guide wire with built-in magnets and sensors, a vascular network map obtained from X-ray images, a marking system that designates the treatment affected area position on the vascular network map, and a position that transmits the position of the tip of the guide wire at any time to the treating doctor The transmission system calculates and transmits to the treating physician information consisting of torque, wire push-in amount and rotation angle required to guide the guidewire tip to the next target position at the next time, that is, after a predetermined time interval. It is to develop an information transmission system and a guide wire operation assist system that assists the treatment in which the treating physician repeats this operation and finally guides the smart guide wire to the position of the treatment affected area.

The third subject of the present invention is
In the above guide wire operation assist system, it is to develop a guide wire operation robot system in which the operation of the driver is replaced by a robot operation system instead of the treating doctor.

In order to solve the first problem of the present invention, we have developed five new elemental technologies.
The first issue in the development of new elemental technology is to improve the hard magnetic properties of the semi-hard magnetic material of the Cr-Ni stainless steel guide wire, and partially magnetize the tip to 1×10 ^-9 Wbm ~. A Cr—Ni stainless steel magnet having a magnetic moment of 20×10 ⁻⁹ Wbm is used, and the magnetic field generated therefrom is detected by an external magnetic vector sensor grid. We have developed a smart guidewire consisting of a sensor data processor that calculates position and orientation and a display device that displays the calculated position and orientation measurement values (position and orientation display device).
Here, the Cr--Ni stainless steel at the tip of the guide wire consists of a core wire, a spring coil and a reinforcing coil.

The distal end portion of the guide wire is made of Cr--Ni (austenitic) non-magnetic stainless steel which is subjected to strong wire drawing at a workability of 50% or more to increase the strength of the material and enhance the spring property. In order to improve the hard magnetic properties, the Md point, which is a measure of the stability of the austenitic layer of the austenitic stainless steel, is adjusted appropriately to the amount of Cr and the amount of Ni, and the working temperature is set to -50°C to 100°C. to ensure a martensite content of 50-95%.
After that, it is subjected to tension heat treatment at a temperature of 500 to 570°C under a tension of 30 kg/mm ² or less, and the hard magnetic properties are changed to saturation magnetization of 8,000 to 12,000 G, coercive force of 100 to 200 Oe, and difference of 800 G or more. It improves to a directional magnetic field and a residual magnetism of 6,000 to 10,000G.
The Md point is the temperature at which 50% of the martensite content is generated when 30% cold working is applied, and is represented by formula (1).
Md30 (°C) = 413 - 462 (% C + % N) - 9.2 (% Si) - 8.1 (% Mn) - 13.7 (% Cr) - 9.5 (% Ni) - 6 (% Cu)-18.5 (% Mo) (1)

Magnet properties can be evaluated by the magnitude of the magnetic moment M, which depends on the residual magnetism Br of the magnet, the magnet length and diameter (=volume V), and the permeance coefficient P. Also, the residual magnetism Br depends on the saturation magnetization Ms, crystal magnetic anisotropy Hk, and coercive force Hc of the magnet.

First, the present inventors processed a Cr—Ni stainless steel guide wire at a workability of 50% or more, made the amount of martensite 60% or more, had a saturation magnetization Ms of 10 kG or more, and an anisotropy of 800 G or more. A semi-hard magnetic material having a magnetic field and a coercive force of 100 Oe or more is used. Next, tension heat treatment is performed at 550° C. for 30 minutes under a tension of 25 kg/mm ² to magnetize in the drawing direction, that is, in the direction of the fiber structure. A new finding was obtained that the tensile strength increased by 30% or more compared to the as-processed state, reaching 0.7 T or more.

Specifically, the magnet properties of the guide wire are set such that the amount of martensite is 60% or more, the coercive force is 100 Oe or more, the saturation magnetization is 1 T or more, and the residual magnetism is 0.7 T or more, and the shape of the guide wire is 0.3 mm in diameter. 1 mm, the length of the saturated magnetized portion is 5 mm to 25 mm, and the permeance coefficient is 5 to 80, a magnet having a magnetic moment of 1×10 ⁻⁹ Wbm to 20×10 ⁻⁹ Wbm. found to get
Regarding the tension heat treatment, the residual magnetism Br was improved by about 20% at a heat treatment temperature of 500 to 570° C. and a tension of 5 to 100 kg/mm ² .

It was confirmed that the coercive force of the Cr--Ni stainless steel magnet is about 100 to 200 Oe. This value is considerably smaller than the coercive force of 4 to 40 kOe for ferrite magnets and rare earth magnets, but assuming a normal magnetic field environment of 50 Oe or less by making the magnet shape elongated and having a permeance coefficient of 5 or more, , the demagnetization due to the magnetic field can be avoided. The operating point of the magnet is determined by the permeance coefficient P=L/D (L: magnet length, D: magnet diameter).

FIG. 2 shows an example of measurement results of the magnetic field emitted from a Cr—Ni stainless steel magnet that is part of the wire tip of the guide wire.
Assuming a maximum measurement height (distance from the magnet) of 150 mm, it is necessary to detect a minute magnetic field of 1 to 10 nT. Therefore, we have developed a highly sensitive magnetic vector sensor grid (hereinafter referred to as sensor grid) that can detect minute magnetic fields of 0.1 to 10 nT.

Since the magnetic field is a vector quantity and has three magnetic field components Hx, Hy and Hz at any point, it is necessary to simultaneously measure the three magnetic field components at the same point at any time Ti. A magnetic vector sensor is a magnetic sensor that can simultaneously measure three magnetic field components at any point at any time Ti.
Conventional magnetic positioning systems often use three-axis magnetic sensors. In this case, the measurement positions of the magnetic field components Hx, Hy, and Hz deviate by about 0.5 mm to 2 mm, and the deviations are directly added to the errors in the positional accuracy, thereby increasing the errors.
The present invention is based on the development of a small magnetic vector sensor capable of detecting an nT magnetic field, and by using it, a positional accuracy of 0.1 mm or less is ensured.
The present invention detects the magnetic field from the ultra-small magnet at the tip of the guide wire and determines its position with an accuracy of 0.1 mm. If there is a deviation of 0.1 mm or more, the required accuracy cannot be ensured. In the case of the magnetic vector sensor, since the measured values of the three are determined in the photolithography manufacturing process, the thickness can be suppressed to 5 μm or less. In the present invention, the deviation should be 0.01 mm or less.

Using this sensor grid, we created a calculation program that can detect the magnetic field emitted by a magnet at any position and in any direction, and use the sensor grid data to calculate the position and orientation of the tip of the wire.

If the magnetic field generated from the Cr--Ni stainless steel magnet is insufficient, it is possible to supplementally insert a thin-film magnet into the gap at the tip so that a sufficient magnetic field can be obtained.

The principle of calculating the measurement positions X, Y, and Z of the magnet and the orientations θ and φ of the magnet is that, as a general method, a magnetic field emitted from a magnet oriented in a predetermined direction at a predetermined position is generated at each magnetic vector sensor position. The error function Eij = Σ (εij) ² is created with the difference between the theoretical value of the magnetic field and the measured value of the magnetic field at εij error, and it is partially differentiated by each measurement position Xij, Yij, Zij, and the error function has the minimum value It is known to obtain simultaneous equations and use those equations to calculate the measured positions X, Y, Z of the magnets and the orientations θ, φ of the magnets.

In order to solve the second problem of developing new elemental technology, attention was paid to the SI sensor described in Non-Patent Document 1 as a strain gauge. The miniaturization of the SI sensor is based on the data of Non-Patent Document 1, and as a result of intensive research, the length of the amorphous wire of the SI element is reduced from 30 mm to 3 mm or less, and the diameter of the amorphous wire is reduced from 30 μm to 10 μm. Further, by increasing the excitation frequency from 20 MHz to 200 MHz, it was found that an SI sensor having a length of about 2 mm and a strain gauge factor of 1000 or more can be realized.

Next, the inventor devised a structure in which the SI element can be easily attached to the device under test.
The feature of this structure is that the amorphous magnetostrictive wire (hereinafter referred to as magnetostrictive wire) as a stress detector and the magnetostrictive wire electrodes at both ends of the magnetostrictive wire are provided on the surface of the flexible substrate. It can be fixed to the surface of the device under test with an adhesive.

Furthermore, since the SI element is affected by an external magnetic field at the same time as the strain, the magnetostrictive wire is ring-shaped with permalloy to provide a magnetic shield.
FIG. 3 shows the shape of the SI element produced based on this finding. A typical size is 0.2 mm wide and 2 mm long. The electrodes are wire terminals at both ends of the wire and two electrode terminals for external connection. The outer periphery is surrounded by a permalloy thin film and has a magnetic shielding structure. However, since there are various sizes of guide wires, the above numerical values are not limited as long as the sizes can be attached.

As a circuit of the SI sensor, as shown in FIG. 4, there are a pulse oscillator for applying a pulse current to the magnetostrictive wire and a sample hold for sampling and holding the impedance change corresponding to the strain amount generated in the magnetostrictive wire as the magnetostrictive wire voltage change. and an amplifier circuit that amplifies and outputs the hold voltage. The magnetostrictive wire voltage can also be detected by an electronic circuit such as an integrating circuit method or an impedance analyzer method.

The wire tip consists of a highly springy portion and a relatively soft tip. The distal end portion is curved for convenience of blood vessel route guidance, and the degree of curvature varies depending on the doctor and treatment site. In consideration of this, it is necessary to measure the contact pressure applied to the tip of the wire and the degree of bending. Therefore, as shown in FIG. 5, four SI elements are attached to the tip of the guide wire in 90-degree symmetry, and their outputs are connected to an external electronic circuit by flexible wiring, and the four values (σx1, σx2, σy1, The average value of σy2) was calculated, and the value was obtained as the contact pressure (contact pressure). Here, as an electronic circuit, as shown in FIG. 6, a combination of four electronic circuits shown in FIG. 3 was used.
Further, σx=1/2 (σx1−σx2) and σy=1/2 (σy1−σy2) are obtained as the bending stress (bending stress vector) σxy=(σx, σy) of the wire tip. It is now possible to determine the bending strength (ie bending angle).

In order to solve the third problem of new elemental technology development, as shown in FIG. devised.
Four SI sensor elements (X1, X2, Y1, Y2) are arranged on a flexible substrate diagonally with four-fold symmetry around the origin (point O). Then, the stress in the X-axis direction, σx1 and σx2, is added to the stress (σx1, σx2, σy1, σy2) measured by each SI sensor element, and the stress in the Y-axis direction perpendicular to the X-axis direction is obtained. σy1 and σy2 are added, and then the difference σxy between the added value in the X-axis direction and the added value in the Y-axis direction is calculated by the formula σxy=(σx1+σx2)−(σy1+σy2) to obtain the origin (point O). Allows measurement of torque in position.

The above two torque sensors are attached to the handle of the driver part and the torquer respectively, and the torque sensor on the handle measures the force applied to the rotation of the wire tip. The pressing force was measured. The force applied to the torquer was measured by fixing the handle and rotating the torquer.

From the three values of the torque strength of the torquer, the amount of wire feed, and the contact pressure of the wire tip, it is possible to estimate the appearance of obstacles obstructing the wire tip and the resistance force in the guided blood vessel path. Ta.

Furthermore, in order to solve the fourth issue in the development of new elemental technology, a magnetic scale memory is engraved on the surface of the torquer shaft, and the amount of rotation is measured by a magnetic sensor attached to the end face of the handle side to detect the amount of rotation. invented the device. Thereby, the amount of relative rotation between the handle and the torquer can be measured, and the feed amount of the wire can be calculated from the amount of rotation.

From the torque strength of the torquer, the amount of wire feed, and the contact pressure at the tip of the guidewire, it became possible to estimate the state of obstacles obstructing the path at the tip and the resistance force in the guiding blood vessel path. .

In order to solve the fifth issue of new elemental technology development, a motion sensor consisting of an electronic compass as a rotation angle detection sensor and a 3-axis acceleration sensor as a rotation speed detection sensor is attached to the steering wheel of the driver. We decided to detect the direction and rotation speed.
Here, by adopting an electronic compass that utilizes a GSR sensor, the azimuth accuracy of the electronic compass has been greatly improved from 5 degrees, which is the azimuth accuracy of a general-purpose electronic compass used in smartphones, etc., to about 0.1 degrees. did. The rotation speed can also be measured by attaching a MEMS type gyro sensor at the same time.

Based on the amount of rotation of the driver, the orientation of the tip of the wire, the orientation of the tip of the wire in a bent state, and changes in the orientation, the orientation of the tip is appropriately controlled by the rotation of the driver to efficiently guide along the course. Wires can now be guided.

In order to solve the second problem of the present invention, path information of a blood vessel map measured from time t(0) to t(i-1) until reaching the tip position of the guidewire at a certain time t(i) Create a database that integrates the azimuth/position and movement amount of the tip position of the wire, the torque value on the driver side, the amount of rotation of the handle, the torque and amount of rotation of the torquer, and the measurement values of the wire feed length. At the same time as telling the treating doctor the direction and the amount of small change in position to the tip position to be guided to (i+1), considering the blood vessel state obtained from the X-ray image, that is, the diameter, degree of occlusion, curvature, and distance of the blood vessel Then, based on the above database, the driver's rotation amount and torque, torquer's torque, and torquer's rotation amount required for guidance are calculated and reported to the treating doctor, who then compares the data with the empirical value. treatment while
By repeating this process and creating a database of treatment results, we created a guide wire operation assist system program by making the torque and torquer rotation required for guidance more accurate.

In order to solve the third problem of the present invention, the azimuth and position to the tip position to be guided from an arbitrary time t(i) obtained by the guidewire operation assist system program to the next time t(i+1) are minute. Inform the treating doctor of the amount of change, determine the minute movement amount of the direction and position to the tip position to be guided based on it, enter the value with the input device, and automatically perform the input value so that it can be realized. We calculated the required torque and torque of the driver, the torque of the torquer and the amount of rotation of the torquer, and created a robot system that manipulates the driver with a computer.

In the present invention, the Cr-Ni stainless steel at the tip of the guide wire is partially magnetized after tension heat treatment to form a permanent magnet, and the position thereof is calculated with an accuracy of 0.1 mm or less by a magnetic vector sensor system. The contact pressure between the tip and the blood vessel, and the guidewire with built-in sensors such as a torque sensor, a rotation angle sensor, and a torquer rotation measurement device on the operating driver side at the treating doctor's hand. It is effective in digitizing direction and driver's operation information and transmitting it to the treating doctor to assist the treatment.
Furthermore, at an arbitrary time, the treating doctor is assisted by advising the treating doctor on how to operate, such as the torque to be applied to the driver and the amount of rotation of the torquer, or by performing automatic operation, thereby reducing the X-ray irradiation time. It is a technology that makes it possible.

FIG. 2 is a diagram showing the relationship between the coercive force of a Cr—Ni stainless steel magnet and the amount of martensite. FIG. 2 is a diagram showing the relationship between the magnetic field intensity generated by a Cr—Ni stainless steel magnet and the distance from the magnet. It is a figure which shows the structure of the SI element used for this invention. FIG. 4 is a diagram showing an electronic circuit of an SI sensor used in the present invention; It is a figure which shows a mode that four SI elements (contact pressure sensor element) were attached to the wire front-end|tip. FIG. 4 shows an electronic circuit for simultaneously measuring values from four SI elements; FIG. 4 is a plan view showing a torque sensor element used in the present invention; FIG. 3 is a diagram showing the configuration of a sensor-embedded guidewire;

The first embodiment of the present invention is a sensor data processing obtained from an in vivo sensor, a guide wire with a built-in magnet, a magnetic vector sensor grid placed outside the patient's body (ex vivo), and various sensor data. A smart guidewire consisting of a device and its display.
Here , a method for manufacturing a Cr--Ni stainless steel magnet for a guide wire, which enables the first embodiment, will be described as the first embodiment.

A method for manufacturing a Cr—Ni stainless steel magnet for a guide wire that constitutes a smart guide wire includes:
(1) A wire of Cr—Ni system non-magnetic stainless steel is drawn at a workability of 50% or more to have a diameter of 0.3 mm to 1 mm, and a semi-hard magnetic characteristic having a martensite amount of 50 to 95%. forming a guidewire for a catheter;
(2) The guide wire is subjected to tension heat treatment at a heat treatment temperature of 500 to 570° C. and a tension of 5 to 100 kg/mm ² to improve the semi-hard magnetic properties to a saturation magnetization of 8,000 to 12,000 G and a saturation magnetization of 100 to 200 Oe. a coercive force of , an anisotropic magnetic field of 800 G or more, and a remanent magnetism of 6,000 to 10,000 G;
(3) It has a magnetic moment of 1×10 ⁻⁹ Wbm to 20×10 ⁻⁹ Wbm when saturated magnetized by a length of 5 mm to 25 mm, which is a part of the tip of the modified guide wire. a process of making a magnet;
characterized by consisting of

smart guidewire
Equipped with a guide wire, a magnetic vector sensor grid, a position sensor data processing device and a display device,
The guide wire consists of a wire tip portion, a driver portion, and a wire connecting portion that connects the two,
The wire tip has a coercive force of 100 to 200 Oe, an anisotropic magnetic field of 800 G or more, a residual magnetism of 6,000 to 10,000 G, and a residual magnetism of 1 × 10 ^-9 Wbm to 20×10 ^-9 Wbm consisting of a magnet having a magnetic moment,
A magnetic vector sensor grid is provided in a diagnostic device placed outside the patient's body,
The magnetic vector sensor constituting the magnetic vector sensor grid has a magnetic detection power of 10 nT or less,
a position sensor data processor uses the data measured by the magnetic vector sensor grid to calculate the position and orientation of the tip of the guidewire;
The display device displays the measured values of the position and orientation calculated by the position sensor data processing device.

In addition, the above smart guidewire
The driver part of the guide wire consists of a handle and a torquer,
The handle has a torque sensor that measures the torque applied to the handle,
The torquer comprises a torquer rotation amount measuring device for measuring the amount of rotation of the torquer,
a rotation sensor data processor that calculates the torque and amount of rotation of the driver;
and a display device for displaying the measured values of the calculated torque and rotation amount.

Furthermore, the above smart guidewire
The handle that constitutes the driver of the guide wire is provided with a rotation angle detection sensor that detects the rotation direction and a rotation speed detection sensor that detects the rotation speed,
a rotation detection sensor data processor that calculates the rotational orientation and rotational speed of the driver section;
and a display device for displaying a measured value consisting of the calculated rotational azimuth and rotational speed.

The smart guidewire will be described below.
Improving the hard magnetic properties of the semi-hard magnetic material of the Cr--Ni stainless steel guide wire, and partially magnetizing the tip for a predetermined length to achieve 1×10 ⁻⁹ to 20×10 ⁻⁹ Wbm. A sensor that uses a Cr-Ni stainless steel magnet with a large magnetic moment, detects the magnetic field emitted from it with an external magnetic vector sensor grid, and uses the data of the magnetic vector sensor grid to calculate the position and orientation of the tip of the guide wire. It is a smart guide wire consisting of a data processing device and a display device (position/orientation display device) that displays the calculated position/orientation measurement values.

In addition, it is equipped with a strain gauge that measures the stress applied to the wire tip of this smart guide wire,
The driver part of the guide wire is equipped with a torque sensor, a torquer rotation amount measuring device, a rotation angle detection sensor, and a rotation speed detection sensor,
Equipped with a magnetic vector sensor grid external to the patient's body,
a position sensor data processor that uses data from the magnetic vector sensor grid to calculate the position and orientation of the wire tip;
Equipped with a stress sensor data processing device, a rotation sensor data processing device, and a rotation detection sensor data processing device that calculate the contact pressure and bending stress of the wire tip, and the torque, rotation amount, rotation direction, and rotation speed of the driver, respectively,
A smart guidewire comprising a display for displaying calculated measurements.
A detailed description will be given below with reference to FIGS.

(1) The basic function of the smart guidewire is to equip a part of the wire tip 41 of the guidewire 4 to be inserted into the living body with a magnet 415, and place a magnetic vector sensor grid (not shown) outside the patient's body. A position/orientation (abbreviated as position) sensor data processor is provided for detecting the magnetic field emitted from the magnet by the magnetic vector sensor grid and using the detected data to calculate the position and orientation of the tip of the guidewire. Then, the position and orientation of the distal end portion of the guidewire are transmitted to the treating physician based on the calculated measurement values by a position/orientation display device (abbreviated as a display device).
In order to achieve this function, the wire tip portion 41 is made of a semi-hard magnetic material such as Cr—Ni stainless steel, and a portion of the wire tip portion 41 extending from the tip of the guide wire 4 is magnetized to obtain a Cr— Composite magnetic wires made of Ni stainless steel magnets are used.

Part of the magnet at the tip of the wire is a Cr-Ni system non-magnetic stainless steel that is strongly worked at a workability of 50% or more to induce a martensite phase of 50% or more and then magnetized in the longitudinal direction. - It is a Ni-based stainless magnet. Appropriately adjusting the Cr content, Ni content, Mn content, Cu content, Mo content, Si content, C content, N content, etc., the Md point, which is a measure of the stability of the austenite layer of austenitic stainless steel, is -50. °C to 100°C. Then, cold working of 50% to 90% is performed at room temperature to secure a martensite amount of 50% to 95%. In addition, since martensite transformation occurs easily when working at a low temperature, it is preferable to work at a low temperature of about -40°C when it is necessary to obtain a large amount of martensite phase with a low working ratio of about 40%.
The Md point is the temperature at which 50% of the martensite content is generated when 30% cold working is applied, and is represented by formula (1).
Md30 (°C) = 413 - 462 (% C + % N) - 9.2 (% Si) - 8.1 (% Mn) - 13.7 (% Cr) - 9.5 (% Ni) - 6 (% Cu)-18.5 (% Mo) (1)

The magnetic properties of the Cr--Ni stainless steel magnet are such that the amount of martensite is set to 50% to 95%, the saturation magnetization of 8,000 to 12,000 G, the coercive force of 100 to 200 Oe, and the difference of 800 G or more are achieved by a predetermined tension heat treatment. A directional magnetic field and residual magnetism of 6,000 to 10,000G were used. This value is considerably smaller than the coercive force of ferrite magnets and rare earth magnets, which is 4k to 40kOe. as a countermeasure against demagnetization in The magnetic field emitted from the Cr—Ni stainless steel magnet at the tip of the wire depends on the strength of the magnetic moment of the magnet. That is, it depends on the diameter and length of the magnet and the amount of martensite. Adjust the diameter, length and amount of martensite of the magnet so that a magnetic field strength of 0.1 mG or more can be obtained at a maximum measurement height (distance from the magnet) of 150 mm, and set them to 1 × They were combined so as to realize a magnetic moment of magnitude of 10 ⁻⁹ Wbm to 20×10 ⁻⁹ Wbm.

A magnetic vector sensor grid arranges a plurality of magnetic vector sensors in a grid.
A GSR sensor with a detection sensitivity of 1 nT was used as the magnetic vector sensor. Four GSR sensors with a length of 2 mm are attached to a three-dimensional element pedestal in the shape of a truncated square pyramid (base length is 6 mm, inclination angle is 30°C) in 90-degree symmetry, and data from the four sensors is sent to the control circuit. A magnetic vector sensor was obtained by connecting them and calculating the magnetic vector.
The detection sensitivity of the magnetic vector sensor is assumed to be 0.1 nT to 10 nT.

As the magnetic vector sensor grid, the magnetic vector sensors were arranged on a sensor board plate having a length of 100 mm and a width of 100 mm in a grid pattern of 9 rows in the length direction and 9 columns in the width direction at intervals of 10 mm. The installation position error between the measurement positions of Hx, Hy, and Hz was set to 10 μm or less.
This sensor grid can detect the magnetic field generated by a Cr-Ni stainless steel magnet in any position and in any direction, and use the sensor grid data to calculate the position and orientation of the wire tip. A program was created and embedded in the position sensor data processor. This measured value is displayed on the display device.

The principle of calculation for determining the magnet measurement positions X, Y, and Z and the magnet orientations θ and φ is a general method. An error function Eij = Σ(εij) ² is created with the difference between the theoretical magnetic field value at each magnetic vector sensor position and the actual magnetic field field measured at each magnetic vector sensor position generated by a magnet oriented in a predetermined direction at a predetermined position as an εij error. Simultaneous equations are obtained by partially differentiating at each measurement position Xij, Yij, Zij, and assuming that the error function takes the minimum value. It is known to calculate and obtain

(2) In addition, the smart guidewire has a strain gauge (contact pressure sensor) 416 that measures the stress applied to the wire tip 41 at the wire tip 41, and the contact pressure and bending force of the wire tip outside the patient's body. A stress sensor data processor is provided for calculating stress. Then, the measured values obtained by calculation are displayed by a contact pressure/bending stress display device (abbreviated as display device).

The strain gauge is an ultra-high-sensitivity compact SI element having a width of 0.3 mm or less, a length of 5 mm or less, a strain gauge factor of 1000 or more, and a flexible substrate. As shown in FIG. 3, the structure of the SI element 10 is such that an amorphous magnetostrictive wire 13 (hereinafter referred to as a magnetostrictive wire), which is a stress detector, and magnetostrictive wire electrodes 161 at both ends of the magnetostrictive wire are placed on the flexible substrate 11 on the surface. , 162, the substrate surface can be easily fixed to the surface portion of the device under test with an adhesive.
Furthermore, when the SI element 10 is affected by an external magnetic field at the same time as being distorted, the magnetostrictive wire may be annularly surrounded by a permalloy 11P for magnetic shielding.

The structure of the SI element will be explained in more detail with reference to FIG.
The SI element 1 has amorphous magnetostrictive wires 13 arranged in grooves 12 of a resist layer 11R formed on a flexible substrate 11, and magnetostrictive wire terminals 14 are provided at both ends of the magnetostrictive wires 13, respectively. The magnetostrictive wire terminals 14 are connected to the magnetostrictive wire electrodes 16 (161, 162) via the connection wiring 15. FIG. A ring-shaped permalloy 11P for magnetically shielding the magnetostrictive wire 13 is formed around the resist layer 11R.

An electronic circuit of the SI sensor is shown in FIG. The electronic circuit 2 comprises a pulse oscillator 21 for applying a pulse current to the magnetostrictive wire 22 , an electronic switch 22 , a high-speed electronic switch 24 and a sample hold circuit 26 comprising a capacitor 25 , and an amplifier 27 .

A pulse oscillator that applies a pulse current to the magnetostrictive wire, a sample-and-hold circuit that samples and holds the impedance change corresponding to the amount of strain generated in the magnetostrictive wire as a magnetostrictive wire voltage change, and an amplifier circuit that amplifies and outputs the hold voltage. consists of The excitation frequency was set to 200 MHz.

The contact pressure applied to the wire tip and the degree of bending are measured considering that the wire tip consists of a portion with high springiness and a relatively soft distal end. For this purpose, as shown in FIG. 5, four SI elements 31 (made of magnetostrictive wires 311) are attached to the core wire 32 at the tip of the wire in 90-degree symmetry as contact pressure sensor elements. It was connected to an electronic circuit outside the body, the average value of the four values (σx1, σx2, σy1, σy2) was calculated, and the value was obtained as the contact pressure P. Here, as an electronic circuit, as shown in FIG. 6, a combination of four electronic circuits shown in FIG. 3 was used.

Further, σx=1/2 (σx1−σx2) and σy=1/2 (σy1−σy2) are obtained as the bending stress vector σxy=(σx, σy) of the wire tip, and the bending direction and bending strength ( That is, it became possible to obtain the bending angle).
Data output from an electronic circuit outside the patient's body is processed by a stress sensor data processing device to obtain contact pressure and bending stress, which are displayed on a display device.

(3) In addition, the smart guidewire is equipped with a torque sensor and a torquer rotation amount measuring device for measuring the torque and rotation amount applied to the handle and the torquer in the driver part, and a torque sensor data processing device and a rotation amount measuring device outside the patient's body. A sensor data processor is provided. Then, the calculated measured values are displayed by a torque/rotation amount display device (abbreviated as a display device).

The structure of the torque sensor element for measuring the surface stress of the test object according to the present invention is obtained by arranging the above four SI elements symmetrically at 90 degrees. Four SI elements (X1, X2, Y1, Y2) are arranged on a flexible substrate diagonally with four-fold symmetry around the origin (point O). σx1 and σx2, which are stresses in the X-axis direction, are added to the stresses (σx1, σx2, σy1, σy2) measured by each SI element, and σy1 and σy1, which are stresses in the Y-axis direction orthogonal to the X-axis direction, are added. σy2 is added, and then the difference σxy between the added value in the X-axis direction and the added value in the Y-axis direction is calculated by the formula σxy = (σx1 + σx2) - (σy1 + σy2) at the position of the origin (O point) Allows measurement of torque.

The structure of the torque sensor element will be explained in detail with reference to FIG.
The torque sensor element 1A comprises a magnetostrictive wire 13 arranged in a groove 12 on a flexible substrate 11, a magnetostrictive wire output terminal 141 at one end of the magnetostrictive wire 13, and a magnetostrictive wire ground terminal 142 at the other end. are arranged (X1, X2, Y1, Y2), and the ground common electrode 160 provided at the origin (point O) and the four magnetostrictive wire ground terminals 142 are connected. The four magnetostrictive wire output terminals 141 are connected to the magnetostrictive wire output electrodes 161 through the wires 15 and are connected to the outside by lead wires (for output electrodes) 17 . The ground common electrode 160 is connected to the magnetostrictive wire ground electrode 162 through the wiring 16, and is connected to the outside by the lead wire 18 (for ground electrode).
The torque sensor consists of a torque sensor element 1A and an electronic circuit 2A shown in FIG.

The above two torque sensors are attached to the handle and torquer of the driver, respectively. The torque sensor on the handle measures the force applied to the wire tip rotation, and the torque applied to the torquer measures the pressing force applied when the wire is inserted and fed. did. The force applied to the torquer was measured by fixing the handle and rotating the torquer. The torque on the handle corresponds to the resistance force when rotating the handle to rotate the guidewire tip.

From the torque strength of the torquer, the amount of wire feed, and the contact pressure at the tip of the guidewire, it became possible to estimate the state of obstacles obstructing the path at the tip and the resistance force in the guiding blood vessel path. .

As for the torquer rotation amount measurement device, a magnetic scale memory is engraved on the shaft surface of the torquer side, and a magnetic sensor attached to the end face of the handle side detects the rotation amount. As a result, the amount of relative rotation between the handle and the torquer can be measured, and the amount of wire feeding can be calculated from the amount of rotation.

(4) Furthermore, the driver unit is equipped with a rotation angle detection sensor for detecting the rotation direction and a rotation speed detection sensor for detecting the rotation speed, and a rotation sensor data processing device is provided outside the patient's body, and the measurement obtained by calculation The value is displayed by the display device.

A motion sensor consisting of an electronic compass and a 3-axis acceleration sensor was attached to the steering wheel to measure the rotational azimuth, the amount of rotation, and the rotational speed of the steering wheel. Here, by adopting an electronic compass that utilizes a GSR sensor, the azimuth accuracy of the electronic compass has been greatly improved from 5 degrees, which is the azimuth accuracy of a general-purpose electronic compass used in smartphones, etc., to about 0.1 degrees. did.

Based on the amount of rotation of the driver, the orientation of the tip of the guide wire and the orientation of the tip of the wire in a bent state, and changes in these, the direction of the tip can be appropriately controlled by rotating the driver to efficiently follow the course. can guide the guidewire.

The configuration of the guidewire in the smart guidewire according to the above embodiment will be described with reference to FIG.
The guide wire 4 consists of a wire distal end portion 41, a driver portion 42 and a wire connecting portion. The wire tip portion 41 is composed of a tip (platinum) 411 at the distal end, a core wire 412 made of Cr—Ni stainless steel made of a semi-hard magnetic material, a reinforcing coil 413 and a spring coil 414. A portion of the core wire 412 is magnetized to form a Cr—Ni stainless steel magnet 415 , and a contact pressure sensor 416 consisting of an SI element 31 for detecting contact pressure and bending stress is arranged on the outer peripheral portion of the core wire 412 .

The driver section 42 includes a handle 42H and a torquer 42T. The steering wheel 42H is provided with motion sensors including a torque sensor 421 for measuring the torque of the steering wheel, an MCU (microcomputer unit) 422, an electronic compass 423 for measuring the rotational azimuth and rotational speed of the steering wheel, and an acceleration sensor 424.

The torquer 42T is provided with a rotation amount measuring sensor 425, which is a torquer rotation amount measuring device for measuring the amount of rotation of the torquer 42T, and a torque sensor 426 for measuring the torque of the torquer 42T.
Rotation of the wire tip 41 is indicated by 41R, rotation of the handle 42H is indicated by 42HR, and rotation of the torquer 42T is indicated by 42TR.

The following has been obtained from the guidewire embodiment.
1) The position and orientation of the tip of the guide wire can be determined by combining the Cr—Ni stainless steel magnet 415 in which part of the wire tip 41 is magnetized, an external magnetic vector sensor grid, and a position calculation data processing device. It became so.
2) Four strain gauges (SI elements) at the tip of the wire made it possible to measure the contact pressure at the tip of the wire, the bending stress at the tip, the angle, and the direction of bending.
3) The torque sensor 426 attached to the torquer 42T of the driver unit 42 can measure the wire pushing pressure and the torquer rotation amount measuring device 425 (rotation amount measuring sensor) can measure the wire feed length by the torquer 42T. Ta.
4) Torque sensors (421, 426), rotational azimuth (423), and tachometer (424) attached to the driver unit 42 allow quantitative understanding of the operational relationship between the orientation of the tip of the guide wire and the amount of rotation. It became possible.

As described above, the smart guidewire with the built-in sensor and magnet enables guidewire insertion treatment, which until now relied on the experience and intuition of the treating physician, to quantitatively understand the movement of the tip of the guidewire by the driver at hand. It is expected that the treating physician will be able to perform treatment while observing the numerical relationship between the two, and that treatment will be performed more quickly and accurately.

The second embodiment of the present invention consists of a guidewire manipulation assist system program using the smart guidewire with built-in sensor.
A smart guidewire, a vascular network map obtained from an X-ray image, a marking system that specifies the position of the affected area for treatment on the vascular network map, a system that communicates the guidewire tip position at any time to the treating doctor, and the following: A system that calculates and transmits to the treating doctor the torque, wire pushing amount, and rotation angle required to guide the guidewire tip to the next target position at the time, that is, after a predetermined time interval, and repeats this operation. It is a guide wire manipulation assist system that assists the treatment doctor to finally guide the guide wire to the position of the treatment affected area.

The guidewire operation assistance system program is a vascular map path information and a wire tip position measured from time t(0) to t(i) until reaching the tip position of the guidewire at a certain time t(i). A database that integrates the azimuth/position, amount of movement, torque value on the driver side, amount of rotation of the handle, torque and amount of rotation of the torquer, and measurement values of the wire feed length, and the tip to be guided at the next time t(i+1) A program that calculates minute changes in the orientation and position to the position and conveys it to the treating doctor, and from the state of the blood vessel obtained from the X-ray image, that is, considering the diameter, degree of occlusion, curvature, and distance of the blood vessel, the above database Based on this, the amount of rotation and torque of the driver and torque of the torquer and the amount of rotation of the torquer necessary for guidance are estimated, and the program is transmitted to the treating doctor, and the treating doctor refers to the data and compares it with the empirical value while performing treatment. It consists of a program that repeats this and creates a database of treatment results.
By enhancing the database, it is expected that the torque and amount of torquer rotation required for more accurate guidance can be communicated to the treating physician.

The third embodiment of the present invention is based on the smart guide wire with built-in sensor and the guide wire manipulation assist system program, and automates guide wire manipulation, that is, robot manipulation.
That is, in the above-mentioned guide wire manipulation assist system, the guide wire manipulating robot system replaces the operation of the driver with the robot manipulating system.

The robot operation conveys to the treating doctor the amount of slight change in the orientation and position from an arbitrary time t (i) to the tip position to be guided to the next time t (i+1) obtained by the guide wire operation assist system program, Based on that, determine the amount of minute movement of the direction and position to the tip position to be guided, enter the value with the input device, and automatically calculate the necessary amount of rotation of the driver so that the input value can be realized. and torque and torque of the torquer and amount of rotation of the torquer A robot operation system that calculates a predetermined torque and amount of rotation of the torquer and operates the driver with a computer.

[Example 1]
A Cr—Ni stainless steel magnet 415 and an SI element 416 are arranged in a part of the wire tip portion 41 of the guide wire 4 made of a Cr—Ni stainless steel composite magnetic wire, and torque sensors 421, 426, A torquer rotation amount measuring device 425, a driver rotation angle detection sensor 424, and a rotation speed detection sensor 425 are arranged.
A magnetic vector sensor grid is positioned outside the patient's body, and a position sensor data processor that uses data from the sensor grid to calculate the position and orientation of the wire tip.
A stress sensor data processing device, a rotation sensor data processing device, and a rotation detection sensor data processing device for calculating the contact pressure and bending stress of the wire tip, the torque and rotation amount of the driver part, and the rotation direction and rotation speed of the driver, and calculation It consists of a display device that displays the measured values obtained by

The magnet at the tip of the wire is made of Cr-Ni non-magnetic stainless steel with a degree of working of 80% to induce ^a martensitic phase of 90%. It is a magnet that is magnetized in the longitudinal direction after tension heat treatment at 0.8° C. and has a residual magnetism of 0.8 T. The Md point, which is a measure of the stability of the austenitic layer of austenitic stainless steel, has a Cr content of 18.5%, a Ni content of 8.2%, a Mn content of 1.0%, a Cu content of 0.2%, and a Mo The amount was adjusted to 0.2%, the amount of Si to 0.3%, the amount of C to 0.02%, and the amount of N to 0.02%. Then, by performing 80% cold working at normal temperature, 80% martensite content was ensured.

The performance of the Cr-Ni stainless steel magnet was 12,000G saturation magnetization, 100Oe coercive force, 1000G anisotropic magnetic field and 9,000G residual magnetism. The magnet geometry was 0.5 mm in diameter, 5 mm in length, and had a magnetic moment as large as 5×10 ⁻⁹ Wbm. Moreover, the permeance coefficient was 10, and there was no risk of demagnetization in a normal magnetic field environment of about 50 Oe or less. The magnetic field emitted from the Cr—Ni stainless steel magnet at the tip of the wire was 10 nT at a position 150 mm away from the magnet.

A GSR sensor with a detection sensitivity of 1 nT was used as the magnetic vector sensor. Four GSR sensors with a length of 2 mm are attached to a three-dimensional pedestal in the shape of a truncated square pyramid (base length is 6 mm, inclination angle is 30°C) in 90-degree symmetry. to form a magnetic vector sensor.

As the magnetic vector sensor grid, magnetic vector sensors using this GSR sensor were arranged on a sensor board plate having a length of 100 mm and a width of 100 mm in a grid of 9 rows in the length direction and 9 columns in the width direction at intervals of 10 mm. The number of sensors is 9×9=81. Since one magnetic vector sensor has four magnetic sensors, it is necessary to measure 324 sensors in one measurement. For this purpose, this sensor grid scans the measurements with a fast changeover switch, feeds the values into a microcomputer, integrates 324 data points and outputs them at a rate of 50 Hz.
The magnetic vector sensor grid data is used to calculate the position and orientation of the wire tip.

The SI element 1 attached to the core wire 412 of the wire tip portion 41 is an ultra-high-sensitivity compact strain gauge having a width of 0.2 mm, a length of 2 mm, a strain gauge factor of 1500 and a flexible substrate. The structure of the SI element 1 is as shown in FIG. 162, the substrate surface can be easily fixed to the surface of the device under test with an adhesive.
Furthermore, since the SI element 1 is affected by an external magnetic field at the same time as being distorted, the magnetostrictive wire 13 is annularly surrounded by a permalloy 11P to provide a magnetic shield. Permalloy 11P is a thin film with a width of 0.05 mm and a thickness of 5 μm.
As shown in FIG. 4, the electronic circuit 2 of the SI sensor includes a pulse oscillator 21 that applies a pulse current to the SI element 23 (magnetostrictive wire 13) and a wire voltage change that generates an impedance change corresponding to the amount of strain generated in the magnetostrictive wire 13. It is composed of a sample-and-hold circuit 26 for sampling and holding and an amplifier circuit 27 for amplifying and outputting the hold voltage. The excitation frequency was set to 200 MHz.

As shown in FIG. 5, four SI elements 1 are attached at a position 3 mm from the tip of the wire in 90-degree symmetry, and the outputs are connected to an external electronic circuit by flexible wiring. The average value of σy1, σy2) was calculated, and the value was determined as the contact pressure. Here, as an electronic circuit, a combination of four electronic circuits shown in FIG. 3 as shown in FIG. 6 was used.
Further, σx=1/2 (σx1−σx2) and σy=1/2 (σy1−σy2) are obtained as the bending stress vector σxy=(σx, σy) of the wire tip, and the bending direction and bending strength ( That is, the bending angle) can be obtained.

The structure of the torque sensor element for measuring the surface stress of the test object of the present invention is, as shown in FIG. It is arranged. Four SI elements (X1, X2, Y1, Y2) are arranged diagonally on a flexible substrate 11 with four-fold symmetry around the origin (point O). Then, the stresses in the X-axis direction, σx1 and σx2, are added to the stresses (σx1, σx2, σy1, σy2) measured by each SI element, and the stress in the Y-axis direction perpendicular to the X-axis direction, σy1 and σy2 are added, and then the difference σxy between the added value in the X-axis direction and the added value in the Y-axis direction is calculated by the formula σxy = (σx1 + σx2) - (σy1 + σy2), and the position of the origin (O point) Allows measurement of torsional stress in

The two torque sensors (421, 426) are attached to the handle 42H and the torquer 42T of the driver unit 42, respectively. The pressing force applied during insertion was measured. The force applied to the torquer 42T was measured by fixing the handle 42H and rotating the torquer 42T. The torque applied to the handle 42H corresponds to the resistance force when the handle 42H is rotated to rotate the guidewire tip.

From the three values of the torque strength of the torquer 42T, the amount of wire feed, and the contact pressure at the tip of the guide wire, it is possible to estimate the state of obstacles obstructing the path at the tip and the resistance force in the guiding blood vessel path. Ta.

As for the measuring device for the amount of rotation of the torquer 42T, a magnetic scale memory is engraved on the surface of the shaft on the side of the torquer, and the amount of rotation is detected by a magnetic sensor attached to the end face on the side of the handle. By measuring the amount of relative rotation between the handle and the torquer, it is possible to calculate the feed amount of the wire from the amount of rotation.

From the torque strength of the torquer, the amount of wire feed, and the contact pressure at the tip of the wire, it is possible to estimate the state of obstacles obstructing the path at the tip of the wire and the resistance force in the guiding blood vessel path. Ta.

A motion sensor consisting of an electronic compass 423 (size: 2 mm × 2 mm × thickness 1 mm) and a triaxial acceleration sensor 424 (size: 2 mm × 2 mm × thickness 1 mm) is attached to the steering wheel 42H to measure the rotational azimuth, amount of rotation, and rotational speed of the steering wheel. was measured. Here, an electronic compass utilizing a GSR sensor was adopted, and the azimuth accuracy of the electronic compass was set to 0.1 degree.

Based on the amount of rotation of the driver, the orientation of the distal end portion 41 of the guide wire and the orientation of the distal end portion of the wire in a bent state, and their changes, the direction of the distal end portion is appropriately controlled by the rotational operation of the driver to efficiently set the course. A guide wire could be guided along.

FIG. 8 shows a guide wire 4 incorporating the above sensor.
The position and orientation of the tip of the guide wire 4 could be determined by combining the Cr--Ni stainless steel magnet 415 of the wire tip 41 with an external magnetic vector sensor grid and position calculation data processing device.

The four contact pressure sensors 416 at the tip of the wire were able to measure the contact pressure of the tip of the wire, the bending stress of the tip, the angle, and the direction of bending.

The torque sensor 426 attached to the torquer 42T of the driver unit 42 could measure the wire pushing pressure and the torquer rotation amount measuring device 425 could measure the length of the wire fed by the torquer 42T.

A torque sensor (421) attached to the driver unit 42, a rotating compass consisting of an electronic compass 423 and a three-axis acceleration sensor 424, and a rotational speed calculated from changes in the rotating compass over time. and the amount of rotation can be quantitatively grasped.

As described above, the smart guidewire makes it possible to grasp the quantitative relationship of the movement of the distal end portion 41 of the guidewire by the driver portion 42 at hand, instead of relying on the experience and intuition of the treating doctor until now. It is expected that the treating physician will be able to perform treatment while observing the numerical relationship between the two, and treatment will be performed more quickly and accurately.

[Example 2]
It consists of the smart guide wire described in the first embodiment and the guide wire manipulation assist system program.
The guide wire manipulation assist system program is
The route information of the blood vessel map, the orientation/position of the tip position of the wire, the amount of movement, and the driver measured from time t(0) to t(i) until reaching the tip position of the guidewire at a certain time t(i) side torque value, handle rotation amount, torque and rotation amount of the torquer, and measured values of wire feed length, and the minute azimuth and position to the tip position to be guided at the next time t (i+1) A program that calculates the amount of change and notifies the treating doctor,
Based on the state of the blood vessel obtained from the X-ray image, that is, the diameter, degree of occlusion, curvature, and distance of the blood vessel, the amount of rotation and torque of the driver required for guidance and the torque and rotation of the torquer are determined based on the above database. It consists of a program that estimates the amount and notifies it to the treating doctor, and a program that the treating doctor performs treatment while comparing the data with the empirical value as a reference, and repeats this to create a database of treatment results.
By enhancing the database, it is expected that doctors will be able to communicate the torque and amount of torquer rotation required for more accurate guidance.

[Example 3]
Based on the second embodiment, the guide wire operation is automated, that is, a robot operation is used.
The robot operation conveys to the treating doctor the amount of slight change in the orientation and position from an arbitrary time t (i) to the tip position to be guided to the next time t (i+1) obtained by the guide wire operation assist system program, Based on that, determine the amount of minute movement of the direction and position to the tip position to be guided, enter the value with the input device, and automatically calculate the necessary amount of rotation of the driver so that the input value can be realized. and torque and torque of the torquer and amount of rotation of the torquer A robot operation system that calculates a predetermined torque and amount of rotation of the torquer and operates the driver with a computer.

The present invention enables robot manipulation by incorporating a sensor into the guide wire, and is expected to be widely used as a technology that facilitates treatment manipulation and reduces the X-ray irradiation time. is.

1: SI element (stress impedance sensor element)
11: flexible substrate (substrate), 11R: resist layer, 11P: permalloy, 12: groove, 13: magnetostrictive wire, 14: magnetostrictive wire terminal, 15: wiring, 16 (161, 162): magnetostrictive wire electrode 1A: torque sensor Element 10: SI element (X1, X2, Y1, Y2), 11: flexible substrate, 12: groove, 13: magnetostrictive wire, 141: magnetostrictive wire output terminal, 142: magnetostrictive wire ground terminal, 15: wiring, 160: ground Common electrode 161: Output electrode 162: Ground electrode 17: Lead wire (for output electrode) 18: Lead wire (for ground electrode)
2: electronic circuit 21: pulse oscillator, 22: electronic switch, 23: SI element, 24: high-speed electronic switch, 25: capacitor, 26: sample and hold circuit, 27: amplifier 2A: electronic circuit 21: pulse oscillator, 22 (22A , 22B, 22C, 22D): electronic switch, 23 (23A, 23B, 23C, 23D): SI element, 24 (24A, 24B, 24C, 24D): high-speed electronic switch, 25 (25A, 25B, 25C, 25D) : Capacitor 26 (26A, 26B, 26C, 26D): Sample and hold circuit 27 (27A, 27B, 27C, 27D): Amplifier 28 (28A, 28B, 28C, 28D): Electronic switch 3: Contact pressure sensor element 31: SI element, 311: magnetostrictive wire, 32: core wire, 33: resin coat 4: guide wire 41: wire tip, 411: tip (platinum), 412: core wire, 413: reinforcing coil, 414: spring coil, 415 : Cr--Ni stainless steel magnet, 416: contact pressure sensor (SI element), 41R: wire tip rotation, 42: driver unit, 42H: handle, 42T: torquer, 421: torque sensor, 422: MCU (microcomputer unit), 423: electronic compass, 424: 3-axis acceleration sensor, 425: rotation amount measurement sensor (rotation amount measurement device), 426: torque sensor, 42HR: rotation of handle, 42TR: rotation of torquer

Claims (6)

1. In a method for manufacturing a Cr—Ni stainless steel magnet for a guide wire,
   (1) A wire of Cr—Ni system non-magnetic stainless steel is drawn at a workability of 50% or more to have a diameter of 0.3 mm to 1 mm, and a semi-hard magnetic characteristic having a martensite amount of 50 to 95%. forming a guidewire for a catheter;
   (2) The guide wire is subjected to tension heat treatment at a heat treatment temperature of 500 to 570° C. and a tension of 5 to 100 kg/mm ² to improve the semi-hard magnetic properties to a saturation magnetization of 8,000 to 12,000 G and a saturation magnetization of 100 to 200 Oe. a coercive force of , an anisotropic magnetic field of 800 G or more, and a remanent magnetism of 6,000 to 10,000 G;
   (3) It has a magnetic moment of 1×10 ⁻⁹ Wbm to 20×10 ⁻⁹ Wbm when saturated magnetized by a length of 5 mm to 25 mm, which is a part of the tip of the modified guide wire. a process of making a magnet;
   A method for producing a Cr—Ni stainless steel magnet for a guide wire, comprising:
2. In a smart guidewire comprising a guidewire, a magnetic vector sensor grid, a position sensor data processor and a display,
   The guide wire comprises a wire tip portion, a driver portion, and a wire connecting portion that connects the two,
   The wire tip has a coercive force of 100 to 200 Oe, an anisotropic magnetic field of 800 G or more, an anisotropic magnetic field of 6,000 to 10, A magnet having a remanent magnetism of 000 G and a magnetic moment of 1×10 ⁻⁹ Wbm to 20×10 ⁻⁹ Wbm,
   wherein the magnetic vector sensor grid is provided in a diagnostic instrument positioned outside the patient's body;
   the magnetic vector sensor constituting the magnetic vector sensor grid has a magnetic detection power of 10 nT or less,
   the position sensor data processor uses the data measured by the magnetic vector sensor grid to calculate the position and orientation of the tip of the guidewire;
   The smart guide wire, wherein the display device displays the measured values of the position and orientation calculated by the position sensor data processing device.
3. The smart guidewire according to claim 2,
   the guidewire driver portion comprises a handle and a torquer;
   The handle comprises a torque sensor that measures the torque applied to the handle,
   The torquer comprises a torquer rotation amount measuring device for measuring the amount of rotation of the torquer,
   a rotation sensor data processing device for calculating the torque and amount of rotation of the driver;
   and a display device for displaying measured values of calculated torque and amount of rotation.
4. The smart guidewire according to any one of claims 2 and 3,
   The handle that constitutes the driver of the guide wire is provided with a rotation angle detection sensor that detects a rotation direction and a rotation speed detection sensor that detects a rotation speed,
   a rotation detection sensor data processor for calculating the rotational orientation and rotational speed of the driver section;
   A smart guide wire, comprising: a display device for displaying a measured value consisting of a calculated rotational azimuth and rotational speed.
5. The guidewire operation assist system includes any of the smart guidewires described in claims 2 to 4,
   a vascular network map obtained from an X-ray image;
   a marking system that identifies the location of the affected area to be treated on the vascular network map;
   a position transmission system that transmits the guidewire tip position at any time to the treating doctor;
   An information transmission system that calculates information consisting of the torque, wire pushing amount, and rotation angle required to guide the tip of the guidewire to the next target position at the next time, that is, after a predetermined time interval, and transmits the information to the treating doctor. Consists of
   A guide wire operation assisting system, characterized in that this operation is repeated to assist a treatment doctor to finally guide a guide wire to the position of an affected area for treatment.
6. In the guidewire manipulation assist system according to claim 5,
   A guide wire operating robot system characterized in that the operation of a driver is replaced by a robot operating system instead of that of a treating doctor.
   

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