WO2007125676A1

WO2007125676A1 - Magnetic induction drug delivery system

Info

Publication number: WO2007125676A1
Application number: PCT/JP2007/053479
Authority: WO
Inventors: Akira Sasaki; Norihide Saho; Hisashi Isogami; Hiroyuki Tanaka; Noriyo Nishijima; Hiroshi Iseki; Yoshihiro Muragaki; Shigehiro Nishijima; Shinichi Takeda
Original assignee: Hitachi Medical Corporation; Osaka University
Priority date: 2006-04-26
Filing date: 2007-02-26
Publication date: 2007-11-08
Also published as: JP5062764B2; JPWO2007125676A1

Abstract

It is intended to provide a magnetic induction drug delivery system appropriately usable for clinical purposes by which a magnetic drug intravenously administered to a patient can be induced to an affected part in the patient’s body. To induce a magnetic drug to the affected part in the patient’s body, blood vessels from the heart to the affected part are extracted from a three-dimensional blood flow image picked up with a diagnostic imaging system and the branching points of the extracted vessels are specified. By using the data of the blood vessel branching points having been specified on the three-dimensional blood flow image as described above, a magnetic field generator is located while controlling the migration thereof at such a position as inducing the magnetic drug into a blood vessel toward the affected part at a branching point of the patient’s blood vessels as described above.

Description

Specification

Magnetic induction type drug delivery system

Technical field

[0001] The present invention relates to a magnetic induction type drug delivery technique for guiding a therapeutic agent injected into a patient's body to a desired region such as an affected area using magnetism.

Background art

[0002] In order to treat cancers and tumors in a living body by drug therapy, it is considered effective to concentrate a therapeutic drug on a desired region such as an affected area. One method of intensively administering a therapeutic agent to an affected area at a high density uses an elongated catheter. Insert a long and narrow catheter from the thigh blood vessel, for example, and proceed to the affected area while confirming the position of the catheter tip inside the blood vessel using the image on the diagnostic imaging device, and administer the therapeutic drug to the affected area through the catheter at high density. To do. However, advanced skills are required to advance the catheter to the affected area within the patient.

[0003] A technique that does not require as much skill as a catheter and is commonly used to administer a therapeutic agent to an affected area is a method of injecting the therapeutic agent into a blood vessel of a patient. However, in this method, since the drug is administered intravenously, it is difficult to concentrate the drug on the affected area. As a solution to this problem, a method of guiding a drug to an affected area using magnetic force has been proposed. In Non-Patent Document 1, when a magnet is placed outside a tube having a branching portion and a drug containing ferromagnetic particles is caused to flow into the tube, many of the drugs containing ferromagnetic particles are intended by the magnet. It has been reported that Non-Patent Document 1: THA12P009 "Three-Dimensional Motion Control System of Ferromag netic Particle for Magnetical ly Targeted Drug Delivery System F. Misnima et al. 1 9th International Conference on Magnet Technology, September, 2005, pl47 Disclosure of Invention

Problems to be solved by the invention

[0004] The technology disclosed in Non-Patent Document 1 shows the possibility of flowing a larger amount in the intended direction by a magnet in a blood vessel that branches a therapeutic agent containing magnetic particles. Shi However, there are problems to be solved for clinical application, for example, a method for identifying a blood vessel bifurcation in a patient's body and a method for positioning a magnet with respect to the patient.

[0005] The present invention has been made in view of the above technical background, and an object of the present invention is a clinical method capable of efficiently guiding a drug administered into a patient's body to a desired region such as an affected area with magnetic force. It is an object of the present invention to provide a magnetic induction type drug delivery system suitable for the above.

Means for solving the problem

[0006] The present invention has been made to solve such a problem, and is a magnetic induction type drag equipped with a magnetic field generation device that guides a magnetic drug administered into a blood vessel of a subject in a desired direction. In the delivery system, using the three-dimensional blood flow image of the subject, extraction is performed by an intravascular branch position extracting means for extracting a branch position (intravascular branch position) in the blood vessel, and the intravascular branch position extracting means. Intravascular vessel position information acquisition means for obtaining position information of the intravascular branch position in real space coordinates; and position information in real space coordinates of the intravascular branch position information obtained by the intravascular branch position information acquisition means. And a magnetic field generation device position setting means for setting the position of the magnetic field generation device in the vicinity of the intravascular branch position. To provide a system.

[0007] In the above configuration, a nuclear magnetic resonance imaging apparatus (MRI apparatus), an X-ray CT apparatus, an X-ray imaging apparatus, an ultrasonic apparatus, or the like may be used as a medical image diagnostic apparatus that acquires a three-dimensional blood flow image. it can. In the above configuration, the magnetic field generator can use a superconducting magnet or a normal conducting magnet. Furthermore, in order to efficiently guide the magnetic drug toward the affected area at the blood vessel bifurcation, a superconducting magnet is used as the magnet, and a magnet that can form a long and strong magnetic field outside the magnet, such as a magnet using a superconducting bulk material, is used. It is desirable.

The invention's effect

[0008] According to the present invention, it is possible to provide a magnetic induction type drug delivery system capable of efficiently guiding a magnetic drug to a desired region such as an affected area of a patient. Further, according to the present invention, a magnetic induction type drug delivery system suitable for clinical use can be provided. BEST MODE FOR CARRYING OUT THE INVENTION

[0009] <First Embodiment>

Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram for explaining the configuration of the magnetic induction type drug delivery system 1000 of the present embodiment.

[0010] As shown in the figure, a magnetic induction type drug delivery system 1000 according to the present embodiment includes an image analysis device 1100, a magnetic field generation device 1200, and a control device 220.

[0011] The image analysis device 1100 calculates the real space coordinates of the branch position of the arterial blood vessel connecting the heart and the affected area using the three-dimensional blood flow image of the patient imaged by the image diagnostic device 100. A blood vessel branch position extraction processing unit 1110 that extracts an arterial blood vessel connecting a heart and an affected part from a 3D blood flow image of a patient, identifies a branch position of the extracted arterial blood vessel, and generates a blood vessel branch position information; A coordinate conversion processing unit 1120 that converts the branch position information of the blood vessel generated by the intravascular branch position extraction processing unit 1110 into real space coordinates based on the position of a reference position marker provided on a part of the patient's body; Prepare.

Here, as the diagnostic imaging apparatus 100, an apparatus capable of three-dimensional blood flow imaging such as a nuclear magnetic resonance imaging apparatus (MRI apparatus), an X-ray CT apparatus, an X-ray imaging apparatus, and an ultrasonic apparatus is used. Can do. Hereinafter, in the present embodiment, a case where an MRI apparatus is used as the diagnostic imaging apparatus 100 will be described as an example. In the present embodiment, the image analysis apparatus 1100 is assumed to be included in the control unit of the MRI apparatus. The image analysis apparatus 1100 may be configured to be independent of the image diagnostic apparatus and connected to the image diagnostic apparatus 100. Also, it can be integrated with the control device 220! /.

[0013] The magnetic field generation device 1200 includes a magnet and applies a magnetic field to the blood vessel bifurcation to guide the magnetic drug administered into the blood vessel of the patient toward the affected area. A superconducting magnet or a normal conducting magnet can be used as the magnet. In order to efficiently guide the magnetic drug toward the affected area at the blood vessel bifurcation, a magnet that is a superconducting magnet and can form a strong and long magnetic field outside the magnet, such as a magnet using a superconducting bulk material, is used. It is desirable. Details of the magnet will be described later. The magnetic field generator 1200 includes a magnet holding mechanism 200 that supports a magnet and can freely change the position and orientation of the magnet.

[0014] The control device 220 guides the magnetic drug administered into the blood vessel of the patient toward the affected area. Therefore, the position and orientation in which the magnet included in the magnetic field generator 1200 should be arranged are determined using the branching position of the blood vessel calculated by the image analysis apparatus 1100, and the magnet holding mechanism 200 is arranged so that the magnet is arranged in the determined position and orientation. Control. Details of the control device 220 will be described later.

Next, the diagnostic imaging apparatus 100 that images the blood flow in the patient's body as a three-dimensional blood flow image will be described. As described above, in this embodiment, an MRI apparatus is used as the diagnostic imaging apparatus 100. Hereinafter, it is referred to as the MRI apparatus 100. FIG. 2 is a perspective view of the MRI apparatus 100. The MRI apparatus 100 generally images a body tissue of a patient 2 as a subject using a nuclear magnetic resonance phenomenon, and is a space of a predetermined size in a space that accommodates the patient 2. Includes a magnet that generates a uniform static magnetic field of a predetermined intensity in the region (measurement space) and an irradiation coil that irradiates electromagnetic waves (RF pulses) that cause nuclear magnetic resonance to the atomic nuclei that make up the body tissue of patient 2. A gantry 110 including a radiation system and three sets of gradient magnetic field coils for generating a gradient magnetic field that gives a magnetic field gradient in three directions orthogonal to each other in the measurement space, and a patient 2 are mounted. And a bed 120 that is transported to and positioned in the measurement space. The operations of the irradiation coil, the gradient coil, and the bed 120 are controlled by a control unit 130 having a central processing unit (CPU). Reference numeral 71 is a marker for specifying the position on the patient 2. Details of the marker 71 will be described later.

[0016] The control unit 130 includes an operation console 140 for an operator to input imaging parameters and operation commands, a display 150 as a display device for outputting processing results by the CPU, a mouse trackball and a joystick. The position information input operation device 160 is connected. In addition to the image analysis device 1100, the control unit 130 includes a receiving system including an amplifying unit, an AD converting unit, and a quadrature detecting unit, and a Fourier transform for imaging an MR signal acquired by MR measurement. An image reconstruction unit comprising a plurality of units, and a storage unit for storing the various pulse sequences and the acquired MR signals and the reconstructed MR images. Further, the MRI apparatus 100 is provided with a gradient magnetic field power source for supplying electric power to the gradient coil, as a separate body from the gantry 110, the bed 120, and the control unit 130.

[0017] In the control unit 130, various pulse sequences including the RF pulse, the generation and application timing of the gradient magnetic field, and combinations thereof are stored as software. The familiar pulse sequence is for 2D imaging, which is used to image 2D sections. There are a pulse sequence and a 3D imaging pulse sequence used to image a patient three-dimensionally, and these are also installed in the MRI apparatus 100. Furthermore, the MRI apparatus 100 is a pulse sequence for blood flow imaging that images the blood flow flowing through the body of the patient 2, for example, a phase sensitive method (PS method) pulse sequence, a phase contrast method (Phase Contrast method: PC method). ) Pulse sequence and other pulse sequences for landscape MRA (landscape MR angiography: Contrast-enhanced MRA), multi-station MRA pulse sequence, etc. are installed. These pulse sequences are selectively used as necessary.

[0018] The arrangement of the magnetic induction type drug delivery system 1000 and the diagnostic imaging apparatus 100 is not particularly limited. However, it is desirable to have a configuration in which both of them are arranged adjacent to each other and the subject patient 2 can move smoothly between them.

Next, the magnet provided in the magnetic field generator 1200 will be described. In this embodiment, a superconducting magnet is used as the magnet. FIG. 3 is a configuration diagram of the superconducting magnet 7 provided in the magnetic field generator 1200 of the present embodiment. Superconducting magnet 7 is YBCO (oxide superconductor; YBa Cu

2

The coil wire 20a of the high-temperature superconducting conductor whose main component is O) is made of copper with a diameter of about 25 mm.

3 7

The bobbin 20b is composed of a solenoid magnet 21 having a large number of coils attached to the outside of the bobbin 20b. The coil wire 20a composing the superconducting magnet 7 is fixed between the coil wires 20a by impregnation of the grease and is fixed to the bobbin 20b with an adhesive or the like. The bobbin 20b is coupled to the heat transfer flange 22 made of copper, for example, with a bolt (not shown) or the like through a soft sheet having a high thermal conductivity such as indium, and is thermally integrated. The heat transfer flange 22 is hermetically sealed with a material having a low heat conductivity, for example, a stainless steel cylindrical body 23 by welding, silver brazing, or the like, thereby realizing vacuum airtightness. The other end of the heat transfer flange 23 is hermetically joined to the flange 24 by welding or the like, and the flange 24 is hermetically fixed with a bolt (not shown) through the flange 25 and 0 ring. A refrigerator fixing flange 26 is hermetically integrated with the flange 25 by metallurgical bonding, and a gas flow path switching mechanism (not shown) between the refrigerator fixing flange 26 and the high-pressure gas and the low-pressure gas via a bellows 27 having a vacuum-tightness. For example, a Gifuord 'McMahon helium refrigerator 28 with a built-in ring) is hermetically fixed with a 0 ring and a bolt (not shown). The helium refrigerator 28 includes a helium gas compressor 29, a high pressure helium gas pipe 30, a low pressure helium gas Connected via pipe 31. Connected to the helium refrigerator 28 are a cylinder 32 in which helium gas is adiabatically compressed and thermally expanded, and a cold stage 33 in a cold generating part.

On the other hand, a vacuum vessel cover 34 is disposed on the outer periphery of the solenoid magnet 21 for vacuum insulation. The vacuum vessel cover 34 is hermetically fixed to the flanges 24 and 25 by a flange 35 via bolts (not shown). A magnet position detector (position sensor) 61 for detecting the position of the superconducting magnet 7 and the direction of the magnetic flux generated by the solenoid magnet 21 is attached to the outer peripheral surface of the vacuum vessel cover 34. As this position sensor 61, a known magnetic sensor or optical sensor capable of detecting the center position and the three-axis directions is used. A touch sensor 64 for detecting that the vacuum container cover 34 is in contact with a human body or a bed is attached to the outer surface of the vacuum container cover 34 facing the solenoid magnet 21. The touch sensor 64 has a structure in which a conductive rubber is sandwiched between copper plates and when a predetermined pressure is applied to the conductive rubber, the copper plates sandwiching the rubber are electrically connected to generate a signal, or a light emitting diode. It is possible to use a structure in which photodiodes are arranged so as to face each other, and when an object is positioned between the light emitting diode and the phototransistor, light emitted from the light emitting diode is blocked and a signal is emitted.

[0021] Around the bobbin 20, solenoid magnet 21, heat transfer flange 22, and cold stage 33, which are extremely low temperatures of minus 230 degrees Celsius, are laminated around the room temperature to prevent intrusion of radiant heat from components at room temperature. Radiant insulation 36 is brazed. The spaces 37 and 38 are evacuated by the vacuum pump 39 through the vacuum pipe 40, the valve 41, the vacuum pipe 42, and the valve 43 to form a vacuum insulation space. After the solenoid magnet 21 is cooled to a cryogenic temperature by the helium refrigerator 28, the valves 41 and 43 are closed, and the superconducting magnet 7 and the vacuum pipes 40 and 42 can be separated.

Further, the space 38 is evacuated, whereby the helium refrigerator 28 is pressed against the heat transfer flange 22 by atmospheric pressure. Between the cold stage 33 and the heat transfer flange 22, a heat transfer medium such as an indium sheet or grease is provided, and the heat transfer flange 22 is cooled well by the cold of the cold stage 33 by the pressing force of the atmospheric pressure. The

[0023] When the helium refrigerator 28 is operated while evacuating the spaces 37 and 38 by operating the vacuum pump 39 by the magnet drive control circuit (not shown), the superconducting magnet 21 is cooled to a very low temperature. . When the superconducting magnet 21 is cooled to a cryogenic temperature, the magnet is driven. By energizing the coil wire 20a of the solenoid magnet 21 from the excitation power supply 44 through the power lead wire 45 by the control of the control circuit, a magnetic field of 5 Tesla, for example, is continuously applied to the solenoid center of the solenoid magnet 21. Can be generated.

[0024] The magnetic field distribution around the superconducting magnet 7 of the present embodiment is as shown in FIG. 7, and the axial direction of the magnet having the strongest magnetic field is near the center of the tip of the container housing the superconducting magnet 7. And the strength of the magnetic field decreases with increasing distance from the radial direction. That is, a magnetic gradient is generated in the axial direction and the radial direction of the superconducting magnet 7.

[0025] According to the magnet structure of the present embodiment, the flange 24 and the flange 35 can be integrated with the bolt 25 (not shown) independently of the flange 25. For this reason, the structural members attached to both the flanges 24 and 35 can be integrally formed and can be attached to and detached from the flange 25. That is, according to the magnet structure of the present embodiment, the structure on the superconducting magnet 7 side and the structure on the helium refrigerator 29 side for cooling can be separated. Therefore, even if the superconducting magnets 7 have different specifications, they can be used by being attached to the same helium refrigerator 29 as long as they are superconducting magnets that can be fixed to the same flange 24 (heat transfer part). A variety of superconducting magnets 7 with different diameters, magnet shaft lengths, magnetic field strengths, etc., that can be fixed to the same flange 24, are manufactured, and superconducting magnets 7 with the required specifications are attached to the flange 25. It can be used in combination with the helium refrigerator 29. In this case, since the helium refrigerator 29 can be shared, the cost for constructing the magnetic induction type drug delivery system 1000 can be reduced.

Next, details of the magnetic field generator 1200 will be described with reference to FIG. In this embodiment, a superconducting magnet 7 is provided for each blood vessel branch portion in order to perform magnetic induction of the magnetic drug in each blood vessel branch portion. Fig. 1 shows an example in which there are three branches of blood vessels up to the affected area. That is, the magnetic field generator 1200 of this embodiment includes three sets of the superconducting magnets 7 in order to perform magnetic induction of the magnetic drug at the three blood vessel branch portions.

[0027] Each superconducting magnet 7 includes a rail 10 laid on the floor of a treatment room on which a treatment bed 210 is placed, a drive unit storage box 11 movable on the rail 10 by drive wheels 12, and a drive It is supported by a magnet holding mechanism 200 comprising a column 80 standing upright on the upper surface of the section storage box 11 and a free arm 90 extending from the upper end of the column 80. [0028] Details of the constituent elements constituting the magnet holding mechanism 200 will be described. The rail 10 is disposed on the floor surface of the treatment room adjacent to the bed 210 along the longitudinal direction of the treatment bed 210 and regulates the moving direction of the drive wheels 12 of the drive unit storage box 11. The drive unit storage button 11 stores a drive unit (not shown) including an electromagnetic brake motor for driving the drive wheels 12, a drive circuit, and a gear mechanism in the internal space. The drive unit storage box 11 drives the motor by applying a noise voltage to the motor, and measures the rotation speed or rotation angle with an encoder, so that the moving distance of the drive unit storage box 11 is increased. You can control! /

[0029] The support column 80 is a hollow pillar fixed to the upper surface of the drive unit storage box 11 by screwing or welding or the like, and has a length so that the tip thereof is positioned at a predetermined height on the floor surface force. Is set. At the upper end of the support 80, an arm drive unit storage box 13 storing a free arm drive control mechanism (not shown) that controls the drive of the free arm 90 is disposed. As shown in FIG. 1, the self-arm 90 includes a first arm 14, a first rotary joint 15, a second arm 16, a second rotary joint 17, a third arm 18, and a third arm. And a superconducting magnet container holder 19 provided at the tip of 18. Three motions: rotation around the axis of the first arm 14, planar rotation of the first rotation joint 15 (rotation around the central axis of the cylinder), and rotation of the second rotation joint 17 Is controlled by the universal arm drive control mechanism, so that the universal arm 90 can move the center position of the superconducting magnet 7 attached to the tip of the third arm to an arbitrary position in the real space and the superconducting magnet. Move and control the direction of the axis center of 7 in any direction. Such a universal arm 90 can be realized by diverting the technology of a welding robot or an assembly robot, and therefore detailed description thereof is omitted here.

[0030] It should be noted that the support column 80 may have a structure that can be expanded and contracted, and the height can be controlled by a drive control mechanism. As the expandable structure, for example, a double cylindrical structure having a mechanism in which the inner cylinder moves up and down with respect to the outer cylinder by hydraulic pressure or the like can be adopted. Further, the support column 80 may be configured to be manually movable. In this case, the control device 220 described later detects the movement amount from the rotation amount of the wheel of the drive unit storage box 11 to which the support column 80 is screwed.

[0031] Helium refrigerator 29, vacuum pump 39, excitation power supply 44 and magnet drive control shown in FIG. The circuit (not shown) is arranged in the drive unit storage box 11, and the high-pressure helium gas pipe 30, the low-pressure helium gas pipe 31, and the power lead wire 45 pass through the arm drive unit storage box 13 in the column 80 and at the top of the column, They are bundled and stored in a protective tube 46 made of, for example, a bellows-like polymer material having flexibility, and connected to the superconducting magnet container 7. The protection tube 46 is held by a support ring 47 installed on each arm.

[0032] In the embodiment shown in Fig. 1, among the total three sets of superconducting magnets 7 provided for each extracted or identified blood vessel bifurcation, a magnet that supports the superconducting magnet 7 located in the patient's lower limb direction. The height of the support 80 of the holding mechanism 200 is set lower than the others, but the height of each support 80 may be set as necessary, or the height of the support 80 is changed. Instead, the arm drive unit storage box 13 may be provided so as to be movable in the vertical direction on the side of the column, so that the movable range of the own arm 90 can be expanded.

[0033] The control device 220 receives the position information of the blood vessel bifurcation in the patient obtained by the image analysis device 1100, determines the arrangement position and direction of the superconducting magnet 7 attached to the universal arm 90, and determines the determined position. The position of the drive unit storage box 11 (the column 80) and the movement of the universal arm 90 are controlled so as to be arranged in the direction. A cable is connected from the control device 220 to the drive unit storage box 11 to supply power and control signals from the control unit 220 to the drive unit storage box 11 and the arm drive unit storage box 13. Supply of power and control signals to the arm drive unit storage box 13 is relayed by the drive unit storage box 11 and is performed through a cable extending to the arm drive unit storage box 13 along the inner wall or outer wall of the support column 80. Is called. As another form, signal transmission by radio signals between the control device 220, the drive unit storage box 11 and the arm drive unit storage box 13 is performed for the supply of control signals regardless of the power supply. A mechanism such as a signal transmission mechanism using electromagnetic waves or infrared rays can be used. The control device 220 includes a memory and a CPU, and each control is realized by the CPU executing a program stored in the memory in advance.

Next, the operation of the magnetic induction drug delivery system 1000 according to the first embodiment will be described. FIG. 11 is a flow of magnetic induction drug delivery processing realized by the operation of the magnetic induction type drug delivery system 1000 of the present embodiment. This implementation In the form, it is assumed that the diseased part of the patient has already been identified by the image diagnosis and pathological diagnosis performed in advance. If it is not specified, the patient is imaged in advance using a diagnostic imaging device such as an MRI device, X-ray CT device, X-ray imaging device, ultrasound diagnostic device, or PET (Positron Emission Tomography) device. In addition, pathological diagnosis is also performed to identify the diseased part.

[0035] After the diseased part of the patient is identified, a 3D blood flow image of the region from the heart to the affected part is acquired (3D blood flow image acquisition process: step 2000). This processing is performed by the diagnostic imaging apparatus 1100. In the present embodiment, the MRI apparatus 100 is used. Since the magnetic drug injected intravenously flows through the route of vein → heart → lung → heart → artery → blood vessel bifurcation → affected area, the operator can determine the position of the blood vessel bifurcation between the heart and the affected area. This is because it is required to grasp it as spatial data.

[0036] The operator places the patient 2 on the bed 120 of the MRI apparatus 100, and allows the patient 2 to statically image the region from the heart to the diseased part as an ROI (Region of Interest). Determine the position of the magnetic field generating magnet in the measurement space. Then select the 3D blood flow imaging pulse sequence and prepare for MR imaging. 3D blood flow imaging only needs to be able to depict blood vessels up to the heart force disease area and blood vessels branching between them, so an MR contrast agent containing gadolinium can be applied to the patient prior to imaging. You can inject it into your mouth and don't pour it.

[0037] Since the maximum FOV (FieldofView) in one imaging of the MRI apparatus 100 is limited by the size of the uniform magnetic field of the static magnetic field generating magnet, the ROI of 3D blood flow imaging exceeds the maximum FOV of the MRI apparatus 100 In this case, it is necessary to divide the imaging into multiple times. In such a case, imaging techniques such as the multi-station MRA method and MOTSA (Multi-Overlapping thin Slab Acquisition) method can be used.

[0038] In addition to the selection of the imaging pulse sequence described above, the imaging parameters (FOV, slab thickness, image matrix size, T1 or T2 etc.) are set, and the superconducting magnet 7 described later (in real space) is controlled. Place a marker 71 on the surface of patient 2 as a reference position. The marker 71 is composed of a thin tubular body 72 enclosing a medium suitably sensitive to the nuclear magnetic resonance phenomenon, for example, water, and a position information transmitting device 73 coupled to the tubular body 72. As the position information transmitter 73, for example, a magnetic transmitter of a magnetic sensor or an infrared transmitter of an optical sensor can be used. Further, the position information transmission device 73 may be configured to be detachable from the marker 71.

[0039] Among the markers 71, the tubular body 72 in which water is sealed is within the FOV of MR imaging, and when the patient is viewed in plan (synonymous with imaging in the supine position) The affected part and the tubular body 72 are placed in such a position that they do not overlap with each other so that they are reflected in the three-dimensional blood flow image.

[0040] When imaging preparation including imaging and positioning of the patient is completed, the operator inputs an imaging start command from the operation console 140. When the imaging start command is received via the operation console 140, the control unit 130 controls the irradiation system, the gradient magnetic field power source, and the reception system, and performs irradiation of the RF pulse, application of the gradient magnetic field, and reception of the MR signal. Imaging performed in advance according to the pulse sequence 3D MR signal measurement for 3D blood flow imaging (3D blood flow measurement), that is, MR signal, phase encoding, frequency encoding, scanning Performs 3D measurement with rice encoding. MR signals obtained by 3D blood flow measurement are stored for each measurement in the memory area corresponding to 3D k-space. When the 3D blood flow measurement is completed, the control unit 130 performs 3D Fourier transform on the MR signal stored in the memory space, and performs image reconstruction. A three-dimensional blood flow image is obtained as described above.

[0041] In this three-dimensional blood flow image, the three encoding directions are the body axis direction of the patient placed in the real space, the two directions orthogonal to the body axis, for example, the direction parallel to the bed and the direction orthogonal thereto. The three-dimensional position information corresponding to the real space is obtained by making them correspond to the three directions. In addition, the distance in the 3D image can be easily converted to the distance in the real space using the predetermined length of the real space for one pixel (pixel) in the 3D blood flow image.

[0042] Next, the image analysis apparatus 1100 identifies the vascular system that is connected to the affected area from the heart on the acquired three-dimensional blood flow image, and extracts the vascular bifurcation on the identified vascular system (vascular divergence). Part extraction processing: step 2010). The 3D blood flow image is sent to the image analysis apparatus 1100 built in the control unit 130 of the MRI apparatus 100 and displayed on the screen of the display 150. The 3D blood flow image is displayed on the display screen of Display 150. At this time, the control device 130 gives the three-dimensional blood flow image a three-dimensional coordinate system that is orthogonal to the real space coordinate system where the magnetic induction type drug delivery system 1000 is placed. FIG. 4 shows a 3D blood flow image of patient 2 obtained by the MRI apparatus 100. The procedure of the blood vessel bifurcation extraction process will be described with reference to FIG.

[0043] When the 3D blood flow image is sent to the image analysis device 1100, the image analysis device 1100 first identifies and extracts a blood vessel system connecting the heart 300 and the affected area 310 on the 3D blood flow image. The image analysis apparatus 1100 identifies and extracts the vascular system that connects the heart 300 and the affected part 310, and extracts a known blood flow region between two points, the point A near the heart 300 and the point B near the affected part 310. For example, it is performed by the region expansion method (the region growing method). The points A and B are designated by the operator visually observing the three-dimensional blood flow image displayed on the display 150 and manually operating the position information input operator 160. For example, specify with the cursor or enter the coordinates of point A and B.

[0044] When the identification and extraction of the blood flow (blood vessel system) connecting the heart 300 and the affected area 310 is completed, the image analysis apparatus 1100 extracts and specifies the branch (blood vessel branch) in the extracted blood vessel system. . The blood vessel branch portion specified here becomes a target of the superconducting magnet 7.

[0045] There are several possible methods for extracting and specifying the blood vessel bifurcation. That

One is a method in which an operator extracts and identifies a blood vessel bifurcation while observing a three-dimensional blood flow image displayed on the display 150. In this case, the blood vessel bifurcation is extracted by the operator visually observing the three-dimensional blood flow image, and using the position information input device 160, the blood vessel bifurcations Nl and N2 are moved with the cursor as shown in FIG. Or, specify by inputting coordinate points Nl and N2. The image analysis apparatus 1100 receives the designation of the blood vessel bifurcation from the operator and stores the coordinates. Note that it may be difficult to view even if the 3D blood flow image data is displayed at normal magnification. In that case, you may enlarge the small area including the blood vessel bifurcation to facilitate the above input operation.

[0046] Further, the operator specifies the marker by visual observation on the three-dimensional blood flow image displayed on the screen of the display 150, and uses the position information input device 160 to locate the marker position with the cursor. Or, specify by inputting the coordinate point X that specifies the marker position. The image analysis device 1100 receives the marker position specified by the operator and coordinates Remember.

[0047] The extraction and specification of the blood vessel bifurcation may be performed by the image analysis apparatus 1100 itself. This method will be described with reference to FIG. First, as described above, the blood vessel (blood flow) system connecting the heart 300 and the affected part 310 is specified and extracted by the points A and B as described above. The center line extraction processing of all blood vessels including the branch blood vessels of the extracted blood vessels is executed. Then, from all the points (this is a branch point) where the arterial line connecting the heart 300 and the affected part 310 intersects the branch line, for example, branch points Ml, M2, and M3 shown in FIG. Only the branch points Ml and M2 located on the blood vessel connecting 300 and the affected part 310 are selectively left as a blood vessel branch part, and the remaining branch points are excluded. Through the above processing, the necessary blood vessel bifurcation can be extracted and specified in the present embodiment. A technique for extracting a blood vessel bifurcation by centerline processing is disclosed in Patent Document 3.

Patent Document 3: Japanese Unexamined Patent Publication No. 2006-42969

When the blood vessel branch is extracted and specified by the image analysis device 1100, the image analysis device 1100 performs the above-described processing when receiving an instruction for the operator force to also extract and specify the blood vessel branch, and this embodiment Extract and identify necessary blood vessel bifurcations and store them. Also in this case, the image analysis apparatus 1100 accepts and stores the input of the marker position as the reference position.

[0049] It should be noted that in the extraction and specific processing of the blood vessel bifurcation, the image analysis apparatus 1100 may be configured to detect the marker position. In other words, a marker is composed of a member that shows a specific signal intensity on the screen (having a characteristic shape such as a triangle or quadrangle filled with a substance such as water or magnetic substance), and its position is automatically processed by image processing. recognize. In addition, it should be configured so that a characteristic part of the living body that is not the merging force, such as under the radial arch, is used as an index for specifying the position.

[0050] As described above, when the blood vessel bifurcation Nl, N2, ··· or Ml, M2, ··· and the marker position X as the reference point of the three-dimensional blood flow image are specified, The analysis device 1100 calculates the coordinates of the blood vessel bifurcation Nl, N2, ··· or Ml, M2, ··· on the 3D blood flow image space with reference to the coordinate X of the marker in the real space (Real space coordinate transformation processing: Step 2020). By going through the above process, on the blood vessels connecting the heart 300 and the affected area 310 The blood vessel bifurcation located at, that is, the target of the superconducting magnet 7 can be extracted and identified on the 3D blood flow image. The obtained coordinates in the real space of each blood vessel branch are stored in association with information for specifying the blood vessel branch. Note that when converting to a real space coordinate, the reference coordinate may be configured to directly input a real space coordinate at a position corresponding to the position of the marker 71. The image analysis apparatus 1100 calculates the real space coordinates of each blood vessel bifurcation using the coordinates received by the operator. In this case, the marker 71 (tubular body 72) does not have to be provided when photographing a three-dimensional blood flow image.

[0051] After the real space coordinate conversion processing, the image analysis device 1100 transmits the extracted information of each blood vessel branching unit to the control unit 220. The control unit 220 determines the direction (arrangement direction) of the superconducting magnet 7 for each blood vessel bifurcation using the received information, that is, the direction of the center of the magnetic flux by the superconducting magnet 7 (arrangement direction determination process: step 2030). ). In order to determine the center direction of the magnetic flux by the superconducting magnet 7, information on the traveling direction of the blood vessel at each blood vessel branching portion is required. This is because the superconducting magnet 7 attracts the magnetic drug in the blood vessel branching direction toward the affected blood vessel. Hereinafter, processing performed by the control unit 220 to determine the arrangement direction of the superconducting magnet 7 will be described with reference to FIG.

Here, it is assumed that the number of extracted blood vessel bifurcations is N (N is a natural number). In the n-th (n is a natural number less than or equal to N) blood vessel branching portion Nn, the control unit 220 determines the center point of the blood vessel located at a predetermined distance from the blood vessel branching portion Nn upstream and downstream of the blood vessel branching portion Nn. They are defined as Un and Dn, respectively. Then, an isosceles triangular plane including three points (Un, Nn, Dn) is specified. Then, a straight line that bisects the angle (vertical angle) between the side (Un, Nn) and the side (Dn, Nn) forming the isosceles triangular plane is obtained on the isosceles triangular plane, and the side (Un, Dn Let Cn be the point that intersects). The direction of the straight line (Nn, Cn) is determined as the arrangement direction of the superconducting magnet 7, that is, the center direction of the magnetic flux by the superconducting magnet 7 磁石. The superconducting magnet 7 has its magnetic flux center aligned with the straight line (Nn, Cn) and approaches the body surface of the patient 2 on the extension of the straight line (Nn, Cn) on the point Cn side on the 3D blood flow image. (Fn: Arrangement position) will be arranged. Note that Un and Dn may be configured to be input by the operator. Alternatively, the operator may designate the arrangement direction of the superconducting magnet 7 on the screen. The control unit 220 receives an operator input and determines the arrangement position Fn and the arrangement direction of the superconducting magnet 7. [0053] It should be noted that the force on which the superconducting magnet 7 is desirably arranged so that the straight line (Nn, Cn) coincides with the magnetic flux center of the superconducting magnet 7 is formed by the three-dimensional unevenness on the human body surface. Therefore, if the superconducting magnet 7 is arranged on the straight line (Nn, Cn), the distance between the superconducting magnet 7 and the blood vessel branch may be too far. In such a case, considering that the direction of the superconducting magnet 7 is directed to the blood vessel bifurcation, the magnetic flux center may be slightly shifted by a straight (Nn, Cn) force. The control unit 220 executes the above processing for all the blood vessel branch portions on the blood vessel connecting from the heart 300 to the affected part 310, and determines the arrangement direction of the superconducting magnet 7 in each blood vessel branch portion. The control unit 220 stores the determined arrangement direction in association with information and coordinates that specify each blood vessel branch portion Nn.

[0054] The above processing is performed for each extracted blood vessel bifurcation, and the arrangement position Fn and the arrangement direction in which the tip of the superconducting magnet 7 is arranged on the three-dimensional blood flow image are determined. It should be noted that which vessel bifurcation target each superconducting magnet 7 is determined by the distance between the initial position of each superconducting magnet 7 and the position Fn, and is determined by the operator's instruction. May be. When determining by distance, for example, the one where the initial position of the superconducting magnet 7 in the real space is closest is assigned to each blood vessel bifurcation or each arrangement position Fn. When the placement position Fn assigned to each superconducting magnet 7 and the placement direction (straight line (Nn, Cn) toward the magnetic flux center) are determined, the target blood vessel bifurcation, placement position, and placement direction are determined by the patient. Converted to coordinates or solids in real space with respect to the reference point marker provided on the body. This conversion process is performed based on the size of one pixel of the 3D blood flow image in the real space, that is, “the predetermined direction size of one pixel = FOVZ the number of encodings in the predetermined direction”.

[0055] As described above, when the arrangement position Fn and the arrangement direction of each superconducting magnet 7 are determined on the three-dimensional blood flow image, the control device 220 arranges each superconducting magnet 7 in the determined position and direction. (Positioning process: Step 2040). Hereinafter, the positioning process will be described.

[0056] Patient 2 is placed on the bed 210 of the magnetically guided drug delivery system 1000 shown in FIG. 1 in the same position as when the 3D blood flow image was acquired, and the magnetically guided drug delivery system 1000 is powered on. When introduced, the magnetic induction type drug delivery system 1000 The control device 220 operates, and data relating to the target, arrangement position, and arrangement direction of the superconducting magnet 7 is acquired from the image analysis apparatus 1100. Here, the data regarding the target of the superconducting magnet 7 to be captured specifies the arrangement position Fn of the superconducting magnet 7 in the real space and the direction (straight line (Nn, Cn)) in which the magnetic flux center of the superconducting magnet 7 is directed. Each vector is data based on the marker 72.

The control device 220 generates control data for moving each superconducting magnet 7 from the current position and orientation to the arrangement position and arrangement direction obtained by the arrangement direction determination process. Therefore, first, the control device 220 determines the current position (initial position) of the superconducting magnet 7 in the real space coordinate system with the marker 72 provided on the body of the patient 2 as the reference position (coordinate origin) and the superconducting magnet 7. Direction (initial direction) is detected. The detection is performed by the position sensor 61 attached to the container of the superconducting magnet 7 shown in FIG. 3 detecting its own position and direction with respect to the position sensor (for reference position) 73 provided on the marker 72. The control device 2 20 calculates the difference between the output (initial position and initial direction) of the position sensor 61 of the superconducting magnet 7 and the data (coordinates of the blood vessel bifurcation and the arrangement direction of the superconducting magnet 7) acquired from the image analysis device 1100. Control data is generated.

The control device 220 controls the superconducting magnet 7 so that the position and orientation of the superconducting magnet 7 are set to the placement position and orientation determined by the image analysis device 1100 according to the generated control data. Specifically, by controlling the universal arm drive control mechanism, the position of the support 80 and the position and direction of the superconducting magnet 7 attached to the universal arm 90 are controlled, and the superconducting magnet 7 is brought into the arrangement position. The direction is close and the direction is the arrangement direction. The control detects the current position (initial position) and direction (initial direction) of the superconducting magnet 7 at predetermined time intervals, and takes the difference between the coordinates of the arrangement position and the vector indicating the arrangement direction, respectively. Thus, the control data is generated, and the superconducting magnet 7 is repeatedly moved according to the control data. When the difference becomes 0, the control device 220 determines that the positioning has been completed and ends the control.

[0059] Here, in the control process of the positioning process of the superconducting magnet 7, it is necessary to prevent the container of the superconducting magnet 7 from contacting or pressing the patient. To prevent these, a touch sensor (contact detector) 64 provided at the tip of the container of the superconducting magnet 7 is used. These outputs are also used to control the position and direction of the superconducting magnet 7. For example, in the range where first the superconducting magnet 7 does not contact the patient, only the arrangement direction is matched by feedback control, and then the superconducting magnet 7 is moved closer to the blood vessel bifurcation until there is an output from the touch sensor 64. Move and control the arm 90.

[0060] When positioning of the superconducting magnet 7 is completed as described above, the patient is treated by magnetic induction of the magnetic drug using each superconducting magnet 7 arranged in a desired position and direction (magnetic induction). Processing: Step 2050). First, the control device 220 operates the superconducting magnet 7. Here, a signal for operating superconducting magnet 7 is output from control device 220 to a magnet drive control circuit provided in drive unit storage box 11. The magnet drive control circuit receives the signal, operates the helium refrigerator 28, cools the inside of the superconducting magnet 7, and supplies current from the excitation power source 44 to the coil 20a of the superconducting magnet 7, thereby superconducting. A magnetic field (magnetic flux) is generated in the magnet 7. Magnetic flux generated from the superconducting magnet 7 penetrates into the body of the patient 2 and causes a magnetic gradient in the depth direction of the body at the blood vessel bifurcation.

Thereafter, the control device 220 notifies the operator by an indicator that the superconducting magnet 7 is operated and the magnetic induction type drug delivery system 1000 is on standby. The operator confirmed by the indicator injects the magnetic drug from the predetermined vein position of the patient 2. The magnetic drug injected intravenously flows in the order of the injection position → the vein → the heart → the lung → the heart → the plurality of arteries including the target artery. Then, as shown in FIG. 7, when the magnetic drug 6 diverted to the target artery 4 approaches the blood vessel bifurcation 5 where the superconducting magnet 7 is placed, it is affected by the magnetic field (magnetic flux) 8 by the superconducting magnet 7. Thus, it flows while changing the position to the side surface on the side where the superconducting magnet 7 is located in the blood vessel 4. This is because the strength of the magnetic field generated by the superconducting magnet 7 is larger in the blood vessel 4 on the superconducting magnet 7 side than on the opposite side (causing a magnetic gradient). In the blood vessel bifurcation 5, the magnetic drug 6 flows mostly in the direction of the blood vessel 4a connected to the affected area, and only a small amount flows in the direction of the blood vessel 4b not connected to the affected area. Thus, according to the magnetic induction type drug delivery system 1000 of the present embodiment, a magnetic drug can be guided toward a desired branched blood vessel at a blood vessel branching portion.

According to the experiment of the inventor of the present invention, although depending on the blood flow velocity, the magnetic drug 6 flowed while changing the position to the blood vessel wall side on the side where the superconducting magnet 7 is located in the blood vessel 4 Some are super It has been confirmed that the magnetic agent 6 is attracted by the magnetism of the conductive magnet 7 and stays on the wall surface in the blood vessel 4 facing the surface of the superconducting magnet 7 on the touch sensor 64 side, and the remaining magnetic drug 6 flows along with the blood toward the affected area. When the first portion of the magnetic drug 6 reaches the blood vessel bifurcation 5 and a certain amount of time has passed, the amount of the magnetic drug 6 that stays increases. Then, since the flow of the magnetic drug 6 toward the affected area is inhibited, it is necessary to guide the magnetic drug 6 staying in the blood vessel bifurcation 5 toward the affected area (residual drug induction process). . For this purpose, the inventors of the present invention have devised two methods.

[0063] The first method is a method in which the superconducting magnet 7 is moved away from the blood vessel branching portion 5 (in the direction of arrow E in FIG. 7) to remove or weaken the magnetic gradient in the blood vessel branching portion 5. In the second method, a superconducting magnet 7 positioned at the blood vessel bifurcation 5 is moved along the blood vessel in the direction of the affected area or in a straight line substantially parallel to the blood vessel, or in an arc shape (in the direction of arrow F or arrow G in FIG. The magnetic drug 6 staying in the blood vessel bifurcation 5 is caused to flow into the blood vessel 4a connected to the affected area by the suction force generated by the superconducting magnet 7. Whether these two methods are adopted can be appropriately selected depending on the blood flow rate. The method of V and deviation is also realized by incorporating software for instructing the superconducting magnet 7 to perform each operation in the self-arm drive control mechanism.

For example, when the first method is adopted, the first arm 14, the second arm 16, the third arm 18, the first rotary joint portion 15, and the second rotary joint portion 16 of the free arm 90 are attached to each other. Software that repeats the operation of moving the superconducting magnet 7 toward and away from the blood vessel branching portion in the direction of the straight line (Nn, Cn) in a predetermined time cycle is incorporated in the free arm drive control mechanism. When the second method is adopted, the above-described components of the free arm 90 are driven and controlled to draw a circular arc parallel to a straight line (Nn, Dn) on the isosceles triangular plane. In this way, software that repeats the operation of moving the superconducting magnet 7 by a predetermined distance in a predetermined time cycle is incorporated in the free arm drive control mechanism. In this case, the path for returning the superconducting magnet 7 to the original blood vessel bifurcation 5 may be the same as the forward path, but if possible, the superconducting magnet 7 should be made to be the largest distance comprising the blood vessel bifurcation 5. It is preferable to move the carriage back and forth.

[0065] Further, the retraction and proximity movement of the superconducting magnet 7, the linear movement and return, or A blood flow pulsation cycle is preferably used as a time cycle for performing each of the arc movement and return operations. In this case, the superconducting magnet 7 is held close to the blood vessel bifurcation 5 during a period when the blood flow is slow during the pulsation cycle of the blood flow, and the superconducting magnet 7 is attached to the blood vessel bifurcation 5 when the blood flow becomes fast. By starting the movement away from the blood vessel and controlling it to return to the state where the blood vessel bifurcation 5 is approached by the time when the blood flow is slow, the magnetic drug 6 can be effectively guided toward the affected area. This has been confirmed experimentally by the present inventors. The reason for this is that when the blood flow is delayed, the superconducting magnet 7 is held close to the blood vessel bifurcation 5 so that the magnetic drug 6 stays near the superconducting magnet 7 on the side of the blood vessel wall, It is thought that by moving the superconducting magnet 7 when the blood flow becomes fast, the staying magnetic drug 6 is pushed away toward the blood vessel connected to the affected part by the fast-flowing part in the center of the blood flow. It is done.

Therefore, the stop holding period and the movement start timing in the movement cycle of the superconducting magnet 7 can be set by combining an electrocardiograph and an ultrasonic device with a Doppler measurement function. For example, by measuring the R wave of the electrocardiogram of patient 2 with an electrocardiograph and measuring the blood flow in the blood vessel bifurcation 5 depicted by the probe of the ultrasonic device, the R wave measurement time point The time until high-speed blood flow arrives at the blood vessel bifurcation 5 can be measured.

[0067] At the time of magnetic induction processing of the magnetic drug 6, an electrocardiographic probe is attached to the patient 2 to perform electrocardiogram measurement, and the R-wave measurement time force measured by the electrocardiograph is also measured. The control unit 220 is notified of the result. The control device 220 is incorporated in the universal arm control mechanism so that the time delayed by the arrival time of the high-speed blood flow measured by the electrocardiograph becomes the movement start time of the superconducting magnet 7. Control the software to work.

[0068] Even if the magnetic induction processing procedure for the magnetic drug 6 described above is executed for only one cycle of blood circulation in the blood, the magnetic drug 6 injected into the vein does not move from the heart to the head, arms, and stomach. It is considered that the magnetic drug 6 that is distributed to various parts such as the head and lower limbs and is guided to the affected area is only about several percent of the injected magnetic drug 6. Therefore, in the present embodiment, the system is configured to be controllable so that the magnetic induction process is continuously performed for a predetermined time. For example, if the blood circulation cycle time is several tens of seconds, the blood circulates through the lower extremity with the most heart force and returns to the heart. The range is about the cycle. For example, the control device 220 is provided with a timer capable of setting the time for which the magnetic induction process is continued, so that the time for which the magnetic induction process is continued can be variably set.

[0069] As described above, if the magnetic induction operation is continued for a predetermined time, the drug that has flowed to the organ other than the affected part at the beginning of the injection also flows into the affected part over time while repeating the circulation in the body. The drug is taken up so that it accumulates in the affected cancer cells and tumor cells. As a result, it is expected that the therapeutic effect will be remarkably improved according to the present embodiment as compared with the conventional intravenous injection method for cancer therapeutic agents.

[0070] According to the present embodiment, a predetermined magnetic field can be generated at one or more branch points on the blood flow path based on the information on the three-dimensional position of the blood vessel at each branch point, the size of the blood vessel, and the blood flow velocity. Since the position and angle (arrangement direction) of the correct magnet can be calculated and the magnet can be set at the calculated position and angle, the induction rate of magnetic drug particles to a predetermined affected area such as cancer cells can be increased. it can. In order to guide the magnetic particles in the bloodstream to the target blood vessel branch, a magnet is placed on the side of the blood vessel branch before the blood vessel branch, and the target blood vessel branch is in the blood. You may comprise so that it may attract to the near side. Further, in setting the position and angle of the magnet, the magnetic susceptibility and volume of the magnetic drug to be administered may be considered. For example, in the case of a magnetic agent having a large magnetic field ratio and a small volume, it is easily attracted to a magnetic field and easily flows. Therefore, the magnet is shifted from the branch position to the downstream side and the magnetic field gradient is set to face the downstream side. Conversely, in the case of a magnetic drug having a small magnetic susceptibility and a large volume, the magnet is placed near the branching position.

[0071] In this embodiment, the magnetic field is applied so as to induce the magnetic drug in one direction at the branching portion of the blood vessel, rather than concentratedly applying the magnetic field directly to the affected part. Therefore, the magnetic induction rate of the drug can be improved, and the induction rate of the magnetic drug to the affected area of a predetermined cancer cell can be increased by using a small solenoid coil magnet.

[0072] Further, according to the configuration of the present embodiment, the helium refrigerator can be shared as a plurality of superconducting magnet coolers, so there is no need to provide a helium refrigerator for each superconducting magnet. Therefore, since the system can be realized with a small number of helium refrigerators, the magnetic induction type drug delivery system 1000 can be reduced in size. [0073] <Second Embodiment>

Next, a second embodiment of the present invention will be described. The magnetic induction type drag delivery system 1000 of this embodiment is different from the first embodiment in that a superconducting magnet is formed of a superconducting Baltha body. The following description will focus on differences from the first embodiment.

FIG. 8 shows a configuration of a superconducting magnet 7 (hereinafter referred to as a superconducting Balta magnet 7 in this embodiment) used in the magnetic induction type drug delivery system 1000 according to the second embodiment of the present invention. . In the magnetic induction type drug delivery system 1000 of this embodiment, the high temperature superconducting Balta body 48 of YBCO system is used as the magnetic field generating means instead of the solenoid coil used in the first embodiment, and the high temperature directly in a small refrigerator. A structure for cooling the superconducting Balta body 48 is employed. The outer periphery of the high-temperature superconducting Balta body 48 is integrated with a stainless steel or aluminum ring 49 with an adhesive or the like, and when the high-temperature superconducting Balta body 48 is magnetized, a crack is generated by its own magnetic force. To prevent that. The high-temperature superconducting Balta body 48 and the ring 49 are thermally integrated by being bonded to a heat transfer flange 50 made of copper or aluminum-um with an adhesive or the like. The heat transfer flange 50 and the heat transfer flange 43 are They are joined together with bolts (not shown) via an indium sheet or grease (not shown) and are thermally integrated! The cooling method of the high-temperature superconducting Balta body 48 by the helium refrigerator cold stage 33 is the same as the method of cooling the solenoid magnet 21 described in the first embodiment.

[0075] As is generally practiced, in order to magnetize the high-temperature superconducting Balta body 48, a magnetizing superconducting magnet that generates a predetermined magnetic field to be magnetized, for example, a magnetic field of 10 Tesla, is also included. In addition, the generated magnetic field force and a normal conducting magnet are required, and these are prepared separately (both magnets are not shown).

In the present embodiment, before cooling the high-temperature superconducting bulk body 48, the superconducting Balta magnet 7 incorporating the high-temperature superconducting bulk body 48 is inserted into the magnetic field of the magnetizing magnet, and then the helium refrigeration is performed. The high-temperature superconducting Balta body 48 is cooled below the superconducting temperature by the machine 28. Here, the direction of the cylindrical axis of the superconducting Balta body 48 and the direction of the main magnetic field by the magnetizing magnet must be matched.

[0077] After that, when the magnetic field by the magnetizing magnet is demagnetized, the high-temperature superconducting Balta body that continues to be cooled As long as the magnetic field is captured in 48 and cooling is maintained, the high-temperature superconducting Balta body 48 becomes a superconducting Balta magnet that generates a magnetic field equivalent to the magnetic field generated by the magnetizing magnet. In the present embodiment, the high temperature superconducting bulk material 48 that captures a high magnetic field of 5 to 10 Tesla, for example, is used as the magnetic field generating means. In general, the magnetic field distribution of the superconducting Balta magnet magnetized in this way is formed by a group of micro magnetic fluxes distributed almost uniformly. Therefore, for example, when the high-temperature superconducting Balta body 48 is circular, the magnetic field distribution on the surface thereof is substantially conical, and becomes almost zero at the outer peripheral portion where the magnetic field at the center is strongest. That is, the central force of the high-temperature superconducting Balta body 48 is also directed in the radial direction to form a very large magnetic gradient.

From this, in each blood vessel branching portion 5 of the blood vessel 4 connected to the affected area, as shown in FIG. 9, the central axis of the superconducting Balta magnet 7 is set in the arrangement direction determined in the first embodiment. Thus, the magnetic agent 6 that has flowed into the magnetic field 8 formed by the high-temperature superconducting Balta body 48 is naturally magnetically induced toward the center of the high-temperature superconducting Balta body 48 having a large magnetic gradient. For this reason, since more magnetic drug 6 can be guided to the predetermined vascular tract 4a side by magnetic induction at the blood vessel bifurcation 5, the administration rate of the administered magnetic drug 6 to the affected area such as a predetermined cancer cell is high. There is an effect that can be guided with.

[0079] According to this embodiment, the superconducting Balta body 48 is used as the magnetic field generating means. The superconducting Balta body 48 can be easily magnetized to the vicinity of 10 Tesla, and has a large magnetic field decay rate in the direction away from the surface. That is, since the superconducting Balta magnet 48 is used for the superconducting Balta magnet 7, the superconducting Balta magnet 7 of the present embodiment has a large magnetic field attenuation rate with respect to the direction in which the surface force of the superconducting Balta body 48 moves away, and the magnetic field strength. Is much larger than other magnets such as permanent magnets. Therefore, the magnetic field distribution on the surface of the superconducting Balta magnet 7 can be made equal in intensity, and the magnetic field distribution in the space near the superconducting Balta magnet 7 can be made conical. In other words, the superconducting Balta magnet 7 can form a magnetic field with a high strength and a narrow region where the strength is maximized. Therefore, the magnetic drug 6 in the blood is accurately guided in the guiding direction at the blood vessel bifurcation 5. The effect that can be sucked is born.

[0080] Note that in this embodiment, each of three-dimensional blood flow image acquisition processing, blood vessel bifurcation extraction processing, real space coordinate application processing, placement direction determination processing, positioning processing, and magnetic guidance processing The processing is performed in the same manner as in the first embodiment, using the superconducting Balta magnet 7 instead of the superconducting magnet 7.

[0081] <Third Embodiment>

Next, a third embodiment of the present invention will be described. The magnetic induction type drug delivery system of this embodiment is different from that of the second embodiment in the cooling structure of the superconducting Balta magnet. That is, in the superconducting Balta magnet 7 of this embodiment, as shown in FIG. 10, the YBCO-based high-temperature superconducting Balta body 48 and the helium refrigerator 52 are separated. In the present embodiment, the helium gas power of the working refrigerant is cooled by the cooling heat exchange stage 56 of the helium refrigerator 52 and transported through the flexible vacuum insulation pipe 51 to cool the high-temperature superconducting Balta body 48. It has a structure. Only the differences from the second embodiment will be described below.

The helium refrigerator 52 is connected to the helium gas compressor 53 through a high pressure gas pipe 54 and a low pressure gas pipe 55, and the cooling stage 56 is cooled to an extremely low temperature by the operation of the helium gas compressor 53.

[0083] The helium gas of the working refrigerant is pressurized by the helium gas compressor 57, controlled to a predetermined flow rate by the flow rate adjusting valve 58, passes through the high-pressure pipe 59, and is exchanged in the vacuum heat insulating container 60. Flows into vessel 81.

[0084] The working refrigerant cooled to a low temperature in the heat exchanger 81 is further cooled in a heat exchanger thermally integrated with the cooling stage 56, and is a cryogenic working refrigerant having a temperature of minus 240 degrees Celsius. It becomes. The working refrigerant having reached a very low temperature passes through a pipe 63 disposed in the vacuum space in the vacuum heat insulating pipe 51, and cools the cooling heat exchange stage 64 to a cryogenic temperature. After the cooling heat exchange stage 64 is cooled to a very low temperature, the working refrigerant whose temperature has risen passes through the pipe 65 and flows into the heat exchanger 81, cools the working refrigerant in the high-pressure pipe 59, and connects the low-pressure pipe 66. Return to the helium gas compressor 57 and pressurize again. A laminated heat insulating material 67 is wound around the pipes 63 and 65 to prevent radiant heat.

[0085] The cooling heat exchange stage 64 is supported by, for example, an oleaginous cylinder 69 fixedly supported by a flange 68 that hermetically fixes an end of the vacuum heat insulating pipe 51. The cylindrical body 69 is elastic in its axial direction, and the cooling heat exchange stage 64 is thermally pressed against the heat transfer flange 22 through a heat conductor such as indium or grease. According to the present embodiment, since the helium refrigerator 52 can be installed separately from the container of the superconducting magnet 7, the container of the superconducting magnet 7 can be made small and light. Therefore, the container of the superconducting magnet 7 can be used closer to the body surface of the patient 2 even in a part where the installation space of the superconducting magnet 7 is limited, such as a part having the concave and convex portions of the patient 2, such as the neck. it can.

[0087] Therefore, according to the present embodiment, the magnetic force acting on the magnetic drug 6 can be increased even when there is a blood vessel branch in the uneven part of the body, so that the magnetic drug 6 is guided to the affected area. Probability can be increased, and the proportion of magnetic drug 6 that can be guided to the affected area can be increased.

[0088] Note that in this embodiment, each process of 3D blood flow image acquisition processing, real space coordinate addition processing, blood vessel branching portion extraction processing, arrangement direction determination processing, positioning processing, and magnetic guidance processing The superconducting Balta magnet 7 is used instead of the superconducting magnet 7 and is performed in the same manner as in the first embodiment.

Each embodiment to which the present invention is applied has been described, but the present invention can be variously modified without departing from the scope of the present invention. For example, in each of the above embodiments, the target of the superconducting magnet is a blood vessel branch portion extracted and specified by the method described in each embodiment. However, in some cases, the superconducting magnet target position should be set upstream or downstream of the blood vessel bifurcation depending on the blood flow velocity, not necessarily the blood vessel bifurcation. For example, the position to be the target of the superconducting magnet may be determined by experiment or the like, the difference from the actual position of the blood vessel bifurcation may be obtained as a correction value, and the obtained correction value may be applied.

Further, in each of the above embodiments, a case where a Gifud-McMahon type refrigerator is used as a refrigerator that cools a superconducting solenoid magnet or a high-temperature superconducting Baltha body directly or via a working refrigerant is taken as an example. However, for example, an electronic refrigerator, a solvey refrigerator, a pulse tube refrigerator, a Stirling refrigerator, an acoustic refrigerator, or the like can be used as a refrigerator.

Further, in each of the above-described embodiments, the case where the high-temperature superconducting wire and the superconducting barter body using YBCO as a main component is described as an example, but the present invention is not limited thereto. For example, even if a high-temperature superconducting material made of Gd-based material is used for a coil wire or a balta body It is possible to provide the same or higher magnetic force, and further increase the proportion of the magnetic drug that can be guided to the affected area by further improving the magnetic force.

[0092] Furthermore, in each of the above embodiments, the superconducting magnet is described as an example where the superconducting magnet is attached to a free arm supported by a pillar mounted on a carriage traveling on the floor. It is also possible to adopt a structure that supports the above.

Further, in each of the above-described embodiments, a case where a 3D blood flow image of a patient is acquired by an MRI apparatus is described as an example. As is well known, an image acquired by the MRI apparatus has some distortion due to the magnetic field uniformity of the measurement space. In order to avoid distortion, the ability to take countermeasures against it, or the patient's 3D blood flow image is acquired with an X-ray imaging device, X-ray CT device or ultrasonic diagnostic device without image distortion. As countermeasures, for example, image distortion (correction value) is obtained in advance with a phantom having a three-dimensional cubic lattice, and the correction value is removed from the acquired three-dimensional blood flow image.

Brief Description of Drawings

[0094] FIG. 1 is a perspective view showing a configuration of a magnetic induction type drug delivery system in a first embodiment of the present invention.

FIG. 2 is a perspective view showing a configuration of a nuclear magnetic resonance imaging apparatus that acquires a three-dimensional blood flow image of a patient in the first embodiment of the present invention.

FIG. 3 is a partial cross-sectional view showing a configuration of a superconducting magnet used in the magnetic induction type drug delivery system according to the first embodiment of the present invention.

FIG. 4 is a view for explaining an example of a process for extracting and specifying a blood vessel bifurcation portion of a patient according to the first embodiment of the present invention.

FIG. 5 is a diagram for explaining an example of a process for automatically extracting and specifying a blood vessel bifurcation portion of a patient's three-dimensional blood flow image.

FIG. 6 is a diagram for explaining an example of a process for setting the arrangement direction of the superconducting magnet according to the first embodiment of the present invention.

FIG. 7 is a view for explaining the action of a superconducting magnet on the magnetic drug flowing in the blood vessel according to the first embodiment of the present invention.

FIG. 8 is used in the magnetic induction drug delivery system according to the second embodiment of the present invention. The figure which showed the structure of the superconducting Balta magnet in the partial cross section.

FIG. 9 is a view showing a state where magnetism generated by the superconducting Balta magnet according to the second embodiment of the present invention acts on a magnetic drug at a blood vessel branching portion.

FIG. 10 is a diagram for explaining the structure of a superconducting Balta magnet system from which a refrigerator according to a third embodiment of the present invention is separated.

FIG. 11 is a flow of magnetic induction drug delivery processing of the magnetic induction type drug delivery system according to the first embodiment of the present invention.

Explanation of symbols

2: Patient, 4: Blood vessel, 5: Blood vessel branch, 6: Magnetic drug, 7: Superconducting magnet, 8: Magnetic field, 11: Drive unit storage box, 13: Arm drive unit storage box, 14, 16, 18: Arm 15, 17: Rotating joint, 21: Solenoid magnet, 28: Helium refrigerator, 33: Cold stage, 48: High-temperature superconducting Balta body, 61: Magnet position detector, 64: Touch sensor, 71: Marker, 80: Prop, 90: Swivel arm, 120: Sleeper, 130: Control unit, 140: Operation console, 150: Display, 160: Position information input controller, 200: Magnet holding mechanism, 210: Treatment bed, 220: Control equipment Place

Claims

The scope of the claims

[1] In a magnetic induction type drug delivery system equipped with a magnetic field generator for guiding a magnetic drug administered into a blood vessel of a subject in a desired direction,

An intravascular branch position extracting means for extracting a branch position in the blood vessel (intravascular branch position) using the three-dimensional blood flow image of the subject;

Intravascular branch position information acquisition means for obtaining position information in real space coordinates of the intravascular branch position extracted by the intravascular branch position extraction means;

Magnetic field generator position setting for setting the position of the magnetic field generator in the vicinity of the intravascular branch position using position information in real space coordinates of the intravascular branch position obtained by the intravascular branch position information acquisition means And provided with means

Magnetic induction type drug delivery system characterized by

[2] The intravascular branch position information acquisition means uses the intravascular branch position extracted by the intravascular branch position extraction means based on the position of a reference position marker provided in a part of the subject. Including coordinate conversion means for converting to real space coordinate position

2. The magnetic induction type drug delivery system according to claim 1, wherein:

[3] The magnetic field generator position setting means changes the setting position of the magnetic field generator at a predetermined cycle.

[4] The magnetic field generator position setting means causes the magnetic field generator to move close to and retract from the intravascular branch position at the predetermined period.

The magnetic induction type drug delivery system according to claim 3, wherein:

[5] The magnetic field generator position setting means holds the magnetic field generator close to the intravascular branch position in the first period of the predetermined cycle, and in the second period of the predetermined cycle. Retracting the magnetic field generator from the vicinity of the intravascular branch position.

The magnetic induction type drug delivery system according to claim 4, wherein:

[6] The magnetic field generator position setting means moves the magnetic field generator at a predetermined cycle from the vicinity of the intravascular branch position in a desired direction along the blood vessel or in an arc shape. thing

The magnetic induction type drug delivery system according to claim 3, wherein:

[7] The magnetic field generator position setting means holds the magnetic field generator close to the intravascular branch position in the first period of the predetermined cycle, and in the second period of the predetermined cycle. Moving the magnetic field generator from the intravascular branch position along the blood vessel or moving the arc.

The magnetic induction type drug delivery system according to claim 6, wherein:

[8] The predetermined cycle is a pulsation cycle of blood flow,

The first period is a slow blood flow rate!

The second period is a period in which the blood flow velocity is faster than the blood flow velocity in the first period.

The magnetic induction type drug delivery system according to claim 5 or 7, characterized in that

[9] The magnetic field generator position setting means repeatedly performs the movement of the magnetic field generator close to or away from the intravascular branch position at predetermined time intervals over a plurality of cycles of blood circulation in the body.

The magnetic induction type drug delivery system according to claim 4 or 5, characterized in that

[10] The magnetic field generation device position setting means repeats movement along the blood vessel from the intravascular branch position of the magnetic field generation device or an arcuate movement at predetermined time intervals over a plurality of cycles of blood circulation in the body. To do

The magnetic induction type drug delivery system according to claim 6 or claim 7,

[11] The magnetic field generator is composed of a superconducting magnet.

[12] The magnetic field generator is composed of a superconducting Balta magnet

[13] The magnetic field generator includes a superconducting member, a cooling member, and the superconducting member. A heat transfer section connecting the cooling member section,

2. The magnetic induction type drug delivery system according to claim 1, wherein the heat transfer section has a shape common to a plurality of types of the superconducting member sections.

[14] The magnetic field generation device includes a superconducting member portion, a cooling member portion, and a pipe having a heat insulating structure that connects both portions to circulate the refrigerant,

The cooling member is a refrigerator

[15] It further comprises a position input means and a display means,

The intravascular branch position extracting means accepts an input for designating the intravascular branch position on the three-dimensional blood flow image of the subject displayed on the display means via the position input means. thing

[16] The intravascular branch position extracting means identifies a blood flow system connected to the desired region in the subject's three-dimensional blood flow image, and a blood flow centerline in the identified blood vessel system Execute the process and extract the point where the center lines of each blood flow intersect as the intravascular branch position

[17] It further comprises a position input means and a display means,

The intravascular branch position extracting means designates at least two points for specifying the vascular system connected to the desired region on the three-dimensional blood flow image of the subject displayed on the display means. An input to be received via the position input means, and a vascular system connected to the desired region is specified based on the at least two points.

The magnetic induction type drug delivery system according to claim 16, wherein:

18. The magnetic induction type drug delivery system according to claim 1, wherein one set of the magnetic field generation device is provided for each of the extracted intravascular branch positions.

[19] Blood flow information acquisition means for acquiring blood flow information of the blood flow flowing through the intravascular branch position,

The magnetic field generator position setting means includes position information on the intravascular branch position and the blood vessel. Based on the blood flow information at the inner branch position, the direction of the magnetic flux direction generated by the magnetic field generator is set.

[20] The magnetic field generator position setting means generates the magnetic field in a direction connecting the intravascular branch position and a midpoint of a line segment connecting two points in the blood vessel that are equidistant from the intravascular branch position. Setting the direction of the magnetic flux generated by the device

[21] The magnetic field generation device position setting means includes: a holding unit that holds the magnetic field generation device so that the position of the magnetic field generation device can be set; a support unit that supports the holding unit; and a moving unit that moves the support unit.

The holding portion includes a plurality of arms and an indirect portion that rotatably connects the two arms.

[22] The holding unit further includes a joint drive unit that drives the joint unit,

The magnetic field generating device position setting means drives at least one of the joint driving unit, the support unit, and the moving unit based on positional information of the intravascular branch position to position the magnetic field generating device. A drive control unit for controlling the setting is further provided.

The magnetic induction type drug delivery system according to claim 21, wherein

[23] A drug delivery method in a magnetic induction type drug delivery system comprising a magnetic field generator for guiding a magnetic drug administered into a blood vessel of a subject in a desired direction,

An intravascular branch position extraction step for extracting an intravascular branch position using the subject's three-dimensional blood flow image;

An intravascular branch position information acquisition step for obtaining position information in real space coordinates of the extracted intravascular branch position;

And a magnetic field generator position setting step for setting a position of the magnetic field generator near the intravascular branch position using position information in real space coordinates of the intravascular branch position. A drug delivery method characterized by the above.

In the intravascular branch position information acquisition step, the real space based on the position of a reference position marker provided in a part of the subject, the intravascular branch position extracted in the intravascular branch position extraction step. 24. The drug delivery method according to claim 23, further comprising a coordinate conversion step of converting to a coordinate position.