JP2005163898A - Pressure control valve, pneumatic driving system and puncturing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a puncturing system capable of puncturing a correct position less liable to be affected by strong magnetic field of a MRI device, and to provide a pressure control valve and a pneumatic driving system used in the same. <P>SOLUTION: This pressure control valve comprises a cylindrical pressure control valve main body, a rotary wall accommodated in a pressure control valve main body rotatably by an ultrasonic motor, and having first and second partitions for partitioning the pressure control valve main body into first and second pressure chambers, a third partition for partitioning the first pressure chamber into first and third pressure chambers, an elastic body for connecting the first partition and the third partition, an inlet port connected to the third pressure chamber to introduce a compressed fluid, an opening port connected with the second pressure chamber for discharging the compressed fluid to the external, a first flow channel connected to the pressure control valve main body, a second flow channel for communicating the first flow channel with the first pressure chamber, and a control pressure outlet port connected to the second flow channel and supplying the pressure by the compressed fluid. The first flow channel is connected to the second pressure chamber or the third pressure chamber by the rotation of the second partition. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a puncture system compatible with an MRI apparatus used for treatment of Parkinson's disease and the like, a pressure control valve used in the puncture system, and a pneumatic drive system.

  In general, an MRI (Magnetic Resonance Imaging) apparatus is an apparatus for imaging human tissue using strong magnetism. First, the specimen is placed in a strong static magnetic field so that the hydrogen nuclei in the specimen are directed in one direction. When an electromagnetic wave having a specific frequency in this state is irradiated, hydrogen nuclei absorb the electromagnetic wave energy and are excited to generate a magnetic field. Then, electromagnetic induction is caused by applying a magnetic field perpendicular to the generated magnetic field, and the current detected thereby is analyzed and imaged.

Parkinson's disease, on the other hand, lacks for some reason a substance called dopamine that is made in the substantia nigra of the midbrain and sent to cells in the striatum of the deep brain, and the connection network between the substantia nigra cells and the striatum Symptoms such as hand tremors, muscle rigidity, slow movements, and postural reflexes are mainly observed.
Treatments for Parkinson's disease include pharmacotherapy that administers dopamine and dopamine degradation inhibitors, transplantation of dopamine-producing tissues and surgical treatment such as stereotactic brain surgery, rehabilitation therapy, and diet therapy, but it supplements the lack of dopamine Alternatively, pharmacotherapy for supplementing dopamine is mainly performed from the viewpoint that the progression of Parkinson's disease can be suppressed by securing it. Also, in recent years, stereotaxic surgery can eliminate hand tremors and gait disturbances by accurately inserting a puncture needle, which is a microelectrode, into the deep brain of the thalamus, pallidum, and hypothalamic nucleus. DBS (Deep Brain Stimulation Therapy) that can be performed has attracted attention, and such puncture operation of stereotaxic brain surgery is performed while confirming the position of the puncture needle and the position of the puncture needle with an MRI image or the like.

  However, as described above, the MRI apparatus obtains an image by placing a specimen under a strong static magnetic field, and therefore, surgery is performed using a magnetic medical device such as a pacemaker, an artificial joint, a scalpel or a clip together with the MRI apparatus. This causes malfunction of the apparatus and gives noise to the MRI image. Therefore, there is a problem that it is difficult to perform a puncture operation using a magnetic puncture needle under the use of an MRI apparatus. Even when a non-magnetic puncture needle that is not affected by the magnetic field generated by the MRI apparatus is used as the puncture needle, a solenoid is used for the drive unit of the teletherapy robot when performing surgery by remote operation. Since there are many things, there existed a subject that a malfunction occurred in an apparatus etc. with the magnetic field generated by an MRI apparatus.

In order to cope with such a problem, several inventions and devices have been disclosed.
For example, in Patent Document 1, the position of a device such as a catheter or a puncture needle is detected accurately and in a short time under the name of “magnetic resonance imaging apparatus and preparation method for interventional MRI”. An invention relating to a magnetic resonance imaging apparatus for interventional MRI capable of grasping the position, orientation and traveling direction of a device is disclosed.

Hereinafter, the technique disclosed in Patent Document 1 will be described with reference to FIG.
The magnetic resonance imaging apparatus for interventional MRI shown in FIG. 5 includes a gantry 43 for placing a specimen in a static magnetic field, and the gantry 43 includes a diagnostic space partially formed by a static magnetic field having a uniform intensity. A cylindrical or open type static magnetic field magnet 44 is provided. A gradient magnetic field coil 45 and an imaging probe (RF coil) 40 are installed in the wall and inner space of the static magnetic field magnet 44. The gradient magnetic field coil 45 is composed of X, Y, and Z coils that are superimposed on a static magnetic field and generate gradient magnetic field pulses in the slice direction, phase end code direction, and readout direction. The pulse current supplied to these coils is sent from the sequencer 35. The gradient magnetic field amplifier 32 receives control signals SGx, SGy, and SGz for the gradient magnetic fields Gx, Gy, and Gz in the X-axis, Y-axis, and Z-axis directions. On the other hand, the probe (RF coil) 40 has both functions of a transmission coil and a reception coil, and is connected to the receiver 33 and the transmitter 34. Transmission by the probe (RF coil) 40, that is, application of an RF magnetic field pulse to the specimen, sends the control signal Sf sent from the sequencer 35 to the transmitter 34 to the probe (RF coil) 40 as a transmission RF signal of frequency f. The generated MR signal received by the probe (RF coil) 40 is converted into an RF current signal, sent to the receiver 33, and further processed by the receiver 33 such as amplification, detection, and digitization. It is sent as digital MR data to the host computer 36 via the sequencer 35. The host computer 36 adjusts the gradient magnetic fields Gx, Gy, Gz and the frequency f, sends a control signal Sφ to the receiver 33, and adjusts the reference phase φ of the phase detection in the receiver 33. A memory is provided to control the drive timing of the entire apparatus, scan control for imaging, control for tracking an imaging section to a device such as a puncture needle, and the like. Reference numerals 37, 38, and 39 denote an input device, a display device, and a storage device.

A puncture needle 41 for puncturing or treating a specimen is a thin needle body made of a hard material, and a position sensor 42a for detecting the position of the puncture needle 41 at two predetermined positions of the puncture needle 41. , 42b are provided. Therefore, the puncture needle in the magnetic resonance imaging apparatus is transmitted by transmitting the position detection signals x1, y1, z1, x2, y2, and z2 of the position sensors 42a and 42b to the host computer 36 via the position information calculation circuits 31a and 31b. The position of 41 can be known. The position sensors 42a and 42b are composed of passive elements or active elements such as minute RF detection coils (microcoils), magnetic sensors, or optical sensors, and are magnetic or optical during puncture work as well as during MRI image photography. A position signal is generated and received, converted into an electrical signal, and the signal is sent to the host computer 36. The photographed image displayed on the display 38 automatically selects and displays three orthogonal sections including two position sensors 42a and 42b provided on the puncture needle 41, or at least one of these sections. doing.
By using the magnetic resonance imaging apparatus having the above structure, the use of the MRI apparatus and a surgical operation such as a puncturing operation can be performed in parallel.

  Patent Document 2 discloses an image that can display the position of an insertion object such as a puncture needle inserted into a specimen on an MRI image in real time under the name of “image display method, image display apparatus and MRI apparatus”. Inventions relating to a display method, an image display apparatus, and an MRI apparatus are disclosed.

Hereinafter, the technique disclosed in Patent Document 2 will be described with reference to Patent Document 2.
The MRI apparatus of Patent Document 2 is an imaging device that scans a specimen, a puncture needle that is used for biopsy and drug solution administration with a tip coil attached to the tip, a processing device, an input device that inputs data to the processing device, It comprises a storage device for storing data obtained from the processing device and a display device. Further, the processing device includes a data acquisition unit that acquires scan data from the imaging device, an image reconstruction unit that generates an MR image by performing image reconstruction processing using the scan data, and a three-dimensional chip coil at the tip of the puncture needle A chip coil position detecting unit for detecting the position, an MR image selecting unit for selecting an MR image to be displayed from the MR images stored in the storage device, and a puncture needle position mark indicating the current position of the tip of the puncture needle on the MR image And a mark display section for displaying.
In the MRI apparatus having such a structure, first, the sample is scanned by the imaging apparatus and is taken into the data acquisition unit in the processing apparatus, and further processed by the image reconstruction unit to store the MR image of the slice plane in the storage device. Next, a tip coil position detection sequence at the tip of the puncture needle is executed to calculate the three-dimensional position of the tip of the puncture needle, and a slice plane passing through the three-dimensional position of the tip coil is obtained. Then, the MR image corresponding to this slice plane is taken out from the storage device, and the position of the tip of the puncture needle is displayed as a mark on the MR image. This makes it possible to know the current position of the puncture needle even when using the MRI apparatus. If the tip coil and the distal end of the puncture needle are provided with a tip coil, an insertion direction indicator indicating the insertion direction of the puncture needle can be displayed on the MR image in addition to the puncture needle position mark. Can easily grasp the position and insertion direction of the puncture needle in the body.

  Patent Document 3 discloses an invention relating to an omnidirectional simple stereotaxic device that can be used in combination with a CT (computer tomography) or MRI apparatus under the name “omnidirectional simple stereotaxic device”.

Hereinafter, the technique disclosed in Patent Document 3 will be described with reference to Patent Document 3.
The omnidirectional simple stereotactic brain surgery device of Patent Document 3 includes a metal U-shaped frame fixed to the head of a specimen, a slot provided in a longitudinal direction on an upper straight portion of the U-shaped frame, A puncture needle fixing device that moves left and right along the slot, a puncture needle inserted into the puncture needle fixing device, an arcuate frame that is detachably attached to the puncture needle fixing device and moves together with the puncture needle fixing device, It consists of a puncture needle fixing device attached to the arc frame and a puncture needle inserted into the puncture needle, and the U-shaped frame is a skull fixing pin provided on one side of the U-shaped frame and a skull fixing provided on the other side. The lesion target point is fixed to the specimen head so that the lesion target point comes to the center on the line connecting one of the skull fixing pins on one side and one of the skull fixing pins on the other side by two pins. In addition, the fixed position of the skull fixing pin and the puncture position of the two puncture needles are marked on the scalp in advance using a CT or MRI apparatus.
Therefore, when the cranium fixing pin is fixed to the head of the specimen according to the mark and the tip of the puncture needle of the U-shaped frame is aligned with the puncture needle mark position, the puncture direction of the puncture needle of the arc-shaped frame is determined. The target lesion point can be punctured easily and accurately by inserting the puncture needle into the puncture needle mark position of the puncture needle of the arc frame marked on the scalp.

JP 2002-58658 A JP 2000-210267 A JP 11-137568 A

  However, in the above-described conventional technology, for example, in the invention disclosed in Patent Document 1, a magnetic sensor or an optical position signal obtained by providing a position sensor such as an RF coil on the puncture needle is electrically transmitted. Although it is possible to perform a puncturing operation using the MRI apparatus while grasping the position of the puncture needle in the specimen in real time by converting it into a signal, for example, in the case of an active catheter or the like, a coil or the like is used under a strong magnetic field. There is a problem that noise may be generated due to use of the sensor, and noise due to the strong magnetic field of the MRI apparatus may be superimposed on the transmission / reception signal of the position sensor.

  In the invention disclosed in Patent Document 2, the puncture operation can be performed while using the MRI apparatus by creating the MR image while alternately taking the position detection data of the puncture needle tip and the scan data of the specimen. Although it is possible to obtain MR image data of the specimen in advance and associate the position detection data of the tip of the puncture needle with the MR image, the time when the MR image data of the specimen was obtained and the data related to the puncture needle There is a problem that the difference in the time of acquiring has occurred and the work cannot be performed in real time. Further, the position of the puncture needle is indirectly detected by the chip coil. If the MR image data of the specimen and the position detection data of the puncture needle are to be acquired at the same time, the puncture needle is provided with an MRI generated magnetic field or the like. There is a problem that a large noise is generated in the chip coil, and accurate position data of the puncture needle cannot be obtained or a large noise is superimposed on the MR image data.

  In the invention disclosed in Patent Document 3, although it is possible to puncture the lesion easily and accurately without performing the puncturing operation while viewing the MRI image, a puncture needle using CT or MRI on the scalp in advance. If the puncture operation is not performed properly because the puncture operation is performed without marking the puncture position and the like without seeing the MRI image or the like, there is a possibility that the puncture needle cannot be inserted at an accurate depth from an accurate angle and position. There was a problem that there was.

  The present invention has been made in response to such a conventional situation, and is provided with a puncture system that can be punctured at an accurate position without being affected by the strong magnetic field of the MRI apparatus, and a pressure control valve and a pneumatic drive system used therefor. The purpose is to provide.

In order to achieve the above object, a pressure control valve according to a first aspect of the present invention is housed in a pressure control valve main body formed in a cylindrical shape and a pressure control valve main body that is rotatable by an ultrasonic motor. A first partition that partitions the inside of the valve body into a first pressure chamber and a second pressure chamber, a rotating wall that includes the second partition, and a first pressure chamber that is partitioned within the pressure control valve body A third partition wall that is divided into a pressure chamber and a third pressure chamber, an elastic body that connects the third partition wall and the first partition wall, and a compressed fluid connected to the third pressure chamber in the pressure control valve body. An opening for introducing the fluid, an open port connected to the second pressure chamber in the pressure control valve body and discharging the compressed fluid to the outside, a first flow path connected to the pressure control valve body, and the first A second flow path communicating with the first pressure chamber and the first pressure chamber, and a pressure applied by the compressed fluid connected to the second flow path. And a control pressure output port of the first flow path is to be connected to the second pressure chamber or the third pressure chamber of the pressure control valve body by the rotation of the second partition.
In the pressure control valve configured as described above, the rotational torque of the rotating wall by the ultrasonic motor, the pressure of the compressed fluid taken into the pressure control valve main body from the introduction port, and the first partition that forms the first pressure chamber, The rotating wall is made stationary by balancing the restoring force of the elastic body connecting the third partition, and the pressure supplied from the control pressure output port at that time is adjusted.
The pressure control is performed by controlling the rotational torque of the rotating wall by changing the power parameter applied to the ultrasonic motor, for example, the frequency and phase difference, by driving the rotating wall with the ultrasonic motor. It has the action. This is because the pressure of the compressed fluid flowing in the first and second flow paths, that is, the pressure of the compressed fluid discharged from the control pressure output port is adjusted by adjusting the rotational torque of the rotating wall. Is based.

According to a second aspect of the present invention, there is provided a pneumatic drive system including the pressure control valve according to the first aspect, a compressed fluid supply unit that supplies a compressed fluid to the inlet of the pressure control valve, and a pressure control valve. It has a pneumatic piston driven by a compressed fluid supplied from a control pressure output port, and a pneumatic cylinder containing the pneumatic piston.
In the pneumatic drive system having the above configuration, as described above, the pressure of the compressed fluid discharged from the control pressure output port of the pressure control valve can be controlled by changing the power parameter of the ultrasonic motor that rotates the rotating wall. Since it is possible, the position and drive speed of the pneumatic piston in the pneumatic cylinder are controlled by changing the power parameter of the ultrasonic motor.

According to a third aspect of the present invention, the puncture system is a non-magnetic puncture needle provided on the pneumatic piston of the pneumatic drive system according to the second aspect.
The puncture system having the above-described configuration has an effect of remotely performing an operation of inserting or extracting a non-magnetic puncture needle attached to the pneumatic piston with respect to the affected part of the specimen by controlling the power parameter of the ultrasonic motor.

  In the pressure control valve according to claim 1 of the present invention, the pressure of the compressed fluid discharged from the control pressure output port can be controlled by adjusting power parameters such as the frequency and phase difference of the ultrasonic motor. . The control does not require an element affected by a magnetic field such as a solenoid and can be used in the vicinity of the MRI apparatus without generating electrical noise.

  In the pneumatic drive system according to claim 2 of the present invention, the position of the pneumatic piston in the pneumatic cylinder is adjusted by the pressure of the compressed fluid that is adjusted by the pressure control valve according to claim 1 and discharged from the control pressure output port. Can be moved freely. Since the pressure control valve according to claim 1 is used, it can be used in the vicinity of the MRI apparatus in the same manner.

  In the puncture system according to claim 3 of the present invention, the pressure control valve, the pneumatic drive system, and the pneumatic piston thereof are installed using an ultrasonic motor and air pressure that are not easily affected by the magnetic field generated by the MRI apparatus. By adopting a structure in which the non-magnetic puncture needle can be moved freely, the puncture operation can be performed by remote operation using the MRI apparatus.

  The purpose of providing a puncture system, a pressure control valve and a pneumatic drive system used for the puncture system that can be used without causing disturbance of the MRI image or malfunction of the apparatus even when the MRI apparatus is used, without making the system or the like complicated. It was realized. Examples according to the best mode for carrying out the invention will be described below.

  Examples of the pressure control valve according to the best mode of the present invention will be described below with reference to FIGS.

FIG. 1A is a conceptual diagram of a compression control valve according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along line AA in FIG.
FIG. 1A is a conceptual view of a pressure control valve 1 according to an embodiment of the present invention as viewed from above. The pressure control valve 1 includes a cylindrical pressure control valve main body 2 and the inside thereof as a first pressure. A rotatable rotating wall 6 and a third partition wall 7 having a first partition wall 6e and a second partition wall 6f divided into a chamber 3, a second pressure chamber 4 and a third pressure chamber 5, and a third pressure. A compressed fluid inlet 9 connected to the chamber 5 for introducing the compressed fluid into the pressure control valve body 2 and a compressed fluid connected to the second pressure chamber 4 for discharging the compressed fluid in the pressure control valve body 2 to the outside The opening 10 is composed of a spring 13 that connects the first partition 6 e and the third partition 7. With such a structure, the volumes of the first pressure chamber 3 and the third pressure chamber 5 can be changed by the rotation of the rotating wall 6.
In addition, compressed fluid inlets 11 and 12 are provided at the bottom of the pressure control valve body 2, and the compressed fluid inlet 12 is provided at the bottom of the first pressure chamber 3 and is always connected to the first pressure chamber 3. The compressed fluid inlet / outlet port 11 is connected to the second pressure chamber 4 or the third pressure chamber 5 by the rotation of the rotating wall 6 or is shielded by the second partition wall 6f. The upper portions of the first partition 6e, the second partition 6f, and the third partition 7 are in contact with the inside of the upper portion of the pressure control valve body 2 as shown in FIG. The upper part of the structure is closed. Therefore, the inside of the pressure control valve main body 2 is almost sealed, and the volume of the first pressure chamber 3 and the third pressure chamber 5 varies due to the rotation of the rotating wall 6, and the third pressure from the compressed fluid intake port 9. Pressure is applied to the first pressure chamber 3, the second pressure chamber 4, and the third pressure chamber 5 in the pressure control valve body 2 by the compressed fluid taken into the chamber 5 and the compressed fluid flowing in and out of the compressed fluid inlets 11 and 12. There is a difference. The pressure control valve 1 of the present invention uses this pressure difference to drive the pneumatic drive system and puncture system shown in FIG. Reference numerals 6 a, 6 b and 6 c, 6 d are wall surfaces of the first partition wall 6 e and the second partition wall 6 f, and reference numeral 8 is a shaft serving as a rotation axis of the rotating wall 6.

  Further, as shown in FIG. 1 (b), an ultrasonic motor 15 that is driven by applying a voltage is provided on the upper portion of the pressure control valve body 2, and this is connected to the rotating wall 6 via a shaft 8. By doing so, the rotating wall 6 can be rotated clockwise. Therefore, by rotating the rotating wall 6, the compressed fluid inlet / outlet port 11 provided at the bottom of the pressure control valve main body 2 is connected to the second pressure chamber 4 or the third pressure chamber 5, or the second partition wall 6f is used. Can be closed. Reference numeral 11a is a first flow path connected to the compressed fluid inlet / outlet 11, and reference numeral 12a is a second flow path communicating from the compressed fluid inlet / outlet 12 to the first flow path 11a. Further, the first and second flow paths 11 a and 12 a communicate with the control pressure output port 14. The flow of the compressed fluid inside and outside the pressure control valve main body 2 controlled by the pressure control valve 1 and the operating principle of the pressure control valve 1 will be described later.

Here, the ultrasonic motor 15 in FIG. 1B will be briefly described with reference to FIG.
FIG. 2 is a detailed view of the ultrasonic motor indicated by reference numeral 15 in FIG. 2, the same parts as those shown in FIG. 1B are denoted by the same reference numerals, and the description of the configuration is omitted.

  The ultrasonic motor 15 shown in FIG. 2 is a commercially available ultrasonic motor mainly composed of a slider 17 and a stator 19 (elastic vibration body) to which a piezoelectric vibrator 20 for generating ultrasonic vibration is bonded on the lower surface. The slider 17 is overlaid on the stator 19 in which grooves like comb teeth are formed. Therefore, when the piezoelectric vibrator 20 is excited by applying a specific high frequency voltage to the piezoelectric vibrator 20 on the lower surface of the stator 19, this excitation is also transmitted to the stator 19 bonded to the piezoelectric vibrator 20 and is a stator that is an elastic vibrator. Since a traveling wave traveling in one direction is created on 19, the slider 17 is further pressed against the stator 19 with a constant pressure. As a result, a frictional force is generated between the slider 17 and the stator 19, and the slider 17 moves in a direction opposite to the traveling direction of the traveling wave of the stator 19 by this frictional force. That is, the ultrasonic motor 15 is driven. And the driving force of this ultrasonic motor 15 is converted into the rotational force of the rotating wall 6 of the pressure control valve 1 shown in FIG. Reference numerals 18 and 16 denote a bearing and a case of the shaft 8.

  Next, the operation principle of the pressure control valve 1 will be described with reference to FIG.

FIG. 3A is a conceptual diagram when the rotor is going to rotate counterclockwise, FIG. 3B is a conceptual diagram when the rotor is stationary, and FIG. It is a conceptual diagram when a rotor tries to rotate clockwise. 3, the same parts as those shown in FIG. 1 are denoted by the same reference numerals, and description of the configuration is omitted.
In explaining the principle of operation of the pressure control valve 1, in FIG. 3, an arbitrary voltage is applied to the ultrasonic motor 15 to generate a force to rotate the rotating wall 6 in the clockwise direction. It is assumed that a compressed fluid with a certain pressure is supplied from the inlet 9, that the spring 13 is a tension spring, and that the clockwise direction is positive.

In FIG. 3 (a), the compressed fluid in the first pressure chamber 3 is F ₁ that presses the wall surface 6 a of the rotating wall 6, and the compressed fluid introduced into the third pressure chamber 5 from the compressed fluid inlet 9. Where F _{2 is} the force pushing the wall surface 6d of the second partition wall 6f, F _{s is} the restoring force of the spring 13, F _{m is} the torque generated by the ultrasonic motor 15, and F is the inertial force of the rotating wall 6. The force balance shown in Formula (1) is established between these forces.

Further, when the rotating wall 6 is stationary, the inertial force F does not act on the rotating wall 6, so that F = 0, and the relationship represented by Expression (2) is established. Equation (3) is a rewrite of equation (2). Since restoring force F _s of the force F ₂ and the spring 13 compressed fluid supplied from the compressed fluid inlet 9 to the third pressure chamber 5 presses the wall 6d is substantially constant, the ultrasonic motor from the equation (3) It can be seen that the force F ₁ pushing the wall surface 6 a can be adjusted by changing the magnitude of the torque F _m generated by 15.
Therefore, the negative to positive or inertial force F of Kaidokabe 6 shown in equation (1) by adjusting the force F ₁ pushing the wall surface 6a by changing the magnitude of the torque F _m generated by the ultrasonic motor 15 The rotating wall 6 can be rotated clockwise or counterclockwise. The size and rotational speed of the torque F _m generated by the ultrasonic motor 15 can be increased or decreased by altering or changing the phase difference in a state of fixing the frequency at a constant value, the more the phase difference or frequency It is.

First, as shown in FIG. 3A, in a state where the compressed fluid inlet / outlet 11 is connected to the second pressure chamber 4, the compressed fluid from the compressed fluid inlet 9 passes through the compressed fluid inlet / outlet 11 to the first. Is not supplied to the flow path 11a. Therefore, the compressed fluid supplied to the first pressure chamber 3 passes from the compressed fluid inlet / outlet 12 through the second channel 12a, the first channel 11a, and the compressed fluid inlet / outlet port 11 as indicated by an arrow B in the figure. Then, it flows out into the second pressure chamber 4 and is discharged from the compressed fluid opening 10. Thus, the first pressure chamber 3 is gradually reduced, the force F ₁ pushing the wall surface 6a is reduced.
Meanwhile, since the compressed fluid in the third pressure chamber 5 is supplied from the compressed fluid inlet 9, the force F ₂ pushing the wall 6d remains constant, the restoring force F _s of the spring 13 also remains constant is there.
Here, the torque F _m generated by the ultrasonic motor 15 is constant, a decrease in the force F ₁ pushing the wall surface 6a collapses equilibrium equation (2) Equation (2) to formula (4) change. This is the resultant force of the restoring force F _s of the force F ₂ and a spring 13 pressing the wall 6d working in the negative direction by the reduction of the force F ₁ pushing the wall surface 6a pushes the wall surface 6a working in the positive direction This is because the resultant force is greater than the resultant force of the force F ₁ and the torque F _m generated by the ultrasonic motor 15.
Accordingly, the rotating wall 6 rotates in the counterclockwise direction indicated by the arrow C in FIG. 3A and tries to shift to the next state shown in FIG.

Next, FIG. 3B shows a state in which the rotating wall 6 blocks the compressed fluid inlet / outlet port 11. Suppose that the state of FIG. 3B is shifted from the state of FIG. 3A, for example, by rotating counterclockwise. In this case, if it further rotates counterclockwise in the case a decrease in the force F ₁ pushing the wall surface 6a is large, whereby since the elongation of the spring 13 by the rotation becomes small restoring force F _s of the will spring 13 small In some cases, the balance shown in the equation (2) is maintained again from the relationship shown in the equation (4). In that case, the rotating wall 6 is stationary, and F = 0.
However, if, in the rotated counterclockwise as decrease in the force F ₁ pushing the wall surface 6a than the decrease in the restoring force F _s of the spring 13 is shown in greater further in the arrow D Figure 3 (c) It will be as shown.
In the state shown in FIG. 3C, the third pressure chamber 5 and the first pressure chamber 3 communicate with each other via the first flow path 11a and the second flow path 12a. compressed fluid supplied from the compressed fluid inlet 9, as indicated by G flows into the first pressure chamber 3, a force F ₁ pushing the wall surface 6a by the pressure increases again. Therefore, since the left side of the formula (2) becomes larger this time, the formula (5) is established, and the rotating wall 6 is reversed in the clockwise direction indicated by the arrow E in FIG. That is, the state shifts to the state shown in FIG.
In this way, when the torque F _m generated by the ultrasonic motor 15 is determined, the first pressure chamber 3 is reduced in FIG. 3A and the first pressure chamber 3 is changed in FIG. While pressurizing, the balance in the state shown in FIG. 3B is eventually achieved, and the pressure in the first pressure chamber 3 can be controlled to be constant. The pressure to achieve a force F ₁ pushing the wall surface 6a obtained in state in which the a F = 0 in FIG. 3 (b) becomes the control pressure supplied from the control pressure output port 14.

In the pressure control valve 1 in the present embodiment, the control pressure is the maximum pressure supplied from the compressed fluid inlet 9 and the minimum is the atmospheric pressure. Further, as is understood from equation (3), when trying to get a large control pressure so as to rotate the Kaidokabe 6 by reducing the torque F _m generated by the ultrasonic motor 15 in a counterclockwise the Kaidokabe 6 to increase the torque F _m generated by the ultrasonic motor 15 in the reverse to rotate clockwise in the case of obtaining a small control pressure.
To Kaidokabe 6 at rest in a state shown in FIG. 3 (b), the smaller the torque F _m generated by the ultrasonic motor 15 if required a higher control pressure than the control pressure in that state To do. In such a case, the rotating wall 6 rotates counterclockwise to the state shown in FIG. 3C, and the first pressure chamber 3 is pressurized by the compressed fluid and the control pressure increases. If the rise is too large, the state of FIG. 3 (a) will be exceeded beyond FIG. 3 (b), the pressure will be reduced by the compressed fluid release port 10, and finally the state shown in FIG. 3 (b) will be rotated. The wall 6 is stationary and a desired control pressure can be obtained. On the contrary, when the control pressure in the state is required for the rotating wall 6 stationary in the state of FIG. 3B, the torque F _m generated by the ultrasonic motor 15 is preferably increased.

From the above, by adjusting the torque F _m generated by the ultrasonic motor 15, the force F ₁ pushing the wall surface 6a, that is, the pressure of the compressed fluid supplied to the control pressure output port 14 can be easily controlled. it can. For adjusting the intensity of the torque F _m generated by the ultrasonic motor 15, carried out by switching to the low torque or high torque by changing the power parameters such as a phase difference and frequency as described above.

FIG. 4 is a conceptual diagram of a pneumatic drive system and a puncture system according to an embodiment of the present invention.
In FIG. 4, the pneumatic drive system is a pressure control valve 1a, 1b having the same configuration, operation and effect as the pressure control valve 1 shown in FIGS. 1 and 3, and a compressed fluid is supplied to this via pipes 9a, 9b. And the pneumatic cylinder 21 and the pneumatic piston 22 connected to the pressure control valves 1a and 1b via the pipes 14a and 14b. The puncture system has a pneumatic drive having such a structure. A non-magnetic puncture needle 23 is attached to the pneumatic piston 22 of the system. 4 indicate the moving direction of the compressed fluid discharged from the control pressure output port 14 of the pressure control valves 1a and 1b and the moving direction of the compressed fluid supplied to the pressure control valves 1a and 1b. The pneumatic piston 22 moves in the direction indicated by the arrow I or the arrow J in FIG. 4 by the pressure of the compressed fluid supplied into the pneumatic cylinder 21 through the pipes 14a and 14b. Then, the puncture needle 23 is also moved in the direction indicated by the arrow L or the arrow K in FIG. 4 and can puncture the head 30a of the specimen 30 lying on the bed 29 in the MRI apparatus 28. . Since the puncture system shown in FIG. 4 is compatible with the MRI apparatus, not only the puncture needle 23 but also the pneumatic drive system and the pressure control valve constituting the puncture system are made of a non-magnetic material. That is, the pneumatic cylinder 21, the pneumatic piston 22, the pipes 9a, 9b, 14a, 14b, the pressure control valves 1a, 1b, and the pressure control valve main body 2, the rotating wall 6, the third partition wall 7, and the compression members constituting them The fluid inlet 9, the compressed fluid opening 10, the second flow path 12a, the first flow path 11a, the control pressure output port 14, the spring 13 and the shaft 8 are not affected by the magnetic field generated by the MRI apparatus. Made of magnetic material.

A puncture operation of the puncture system shown in FIG. 4 will be described with reference to FIG.
In the case of puncturing the head 30a of the specimen 30 using the puncture system shown in FIG. 4, first, the pressure control valve 1a is introduced by the computer 25 while introducing a compressed fluid having a constant pressure into the pressure control valves 1a and 1b from the compressor 26. The ultrasonic motor 15 is connected to the ultrasonic motor 15 of the pressure control valves 1a and 1b by controlling the phase difference φ ₁ and the frequency f ₁ of the applied power to the pressure and the phase difference φ ₂ and frequency f ₂ of the applied power to the pressure control valve 1b. The generated torque _Fm is generated.
When the torque F _m applied generated by the ultrasonic motor 15, the force F ₂ pushing force F ₁ pushing the wall surface 6a of the first partition wall 6e to the pressure control valve body _2, the wall surface 6d of the second partition 6f , the balance between the restoring force F _s of the spring 13, Kaidokabe 6 is stopped in a state shown in FIG. 3 (b) while rotating clockwise or counterclockwise. As a result, F ₁ represented by the expression (3) is obtained, and the pressure for applying this force is supplied to the pipes 14a and 14b as the control pressure.
Here, by independently controlling the control pressures for the two pressure control valves 1a and 1b, a pressure difference is generated between the pipe 14a and the pipe 14b, the pneumatic piston 22 is driven, and the puncture needle 23 is moved to the head 30a. Puncture.
When the head 30a is punctured with the puncture needle 23, the compressed fluid may be supplied to the pneumatic cylinder 21 via the pipe 14b shown in FIG. 4 and the pneumatic piston 22 may be moved in the direction indicated by the arrow J. Only the pressure control valve 1b is operated to increase the control pressure while the valve 1a remains stationary. That is, the operating principle of the pressure control valve 1 described with reference to FIG. 3, to rotate the Kaidokabe 6 by reducing the torque F _m generated by the ultrasonic motor 15 and the counterclockwise direction. For example, when the pressure control valve 1b is balanced in the state shown in FIG. 3B, the rotating wall 6 rotates counterclockwise and the state moves to the state shown in FIG. Then, after the control pressure increases, the state returns to the state of FIG. When the operation returns to the state of FIG. 3B again by such an operation, the compressed fluid pressurized from before the operation is sent from the pressure control valve 1b to the pneumatic cylinder 21 through the pipe 14b. The pneumatic piston 22 can be moved in the direction indicated by J. Therefore, the puncture needle 23 can be moved in the direction of arrow K by the movement of the pneumatic piston 22 in the right direction, and the head 30a of the specimen 30 can be punctured.

Conversely, when pulling out the puncture needle 23 from the head 30 a of the specimen 30, the pneumatic piston 22 is moved in the direction indicated by arrow I in FIG. 4 and the puncture needle 23 is moved in the direction indicated by arrow L. That is, contrary to the case of puncturing with the puncture needle 23, only the pressure control valve 1a is operated while the pressure control valve 1b is maintained in the state shown in FIG. The piston 22 is moved in the direction indicated by the arrow I. Referring to FIG. 3, when the head 30a is punctured with the puncture needle 23, the pressure control valve 1a and the pressure control valve 1b are both in the state shown in FIG. 15 state from FIG. 3 (c) is shifted to a state pressure control valve 1a only from the compressed fluid in Figure 3 by reducing only the torque F _m generated (b) is supplied into the pneumatic cylinder 21 via a pipe 14a by So that Then, the right wall surface of the pneumatic piston 22 is pushed by the compressed fluid, and the pneumatic piston 22 is moved in the direction indicated by the arrow I in FIG. Therefore, the puncture needle 23 attached to the pneumatic piston 22 is also moved in the same direction as the movement direction of the pneumatic piston 22, that is, the direction indicated by the arrow L in FIG. 4, and the puncture needle 23 can be pulled out from the head 30a. it can.
In all of the above, the puncture needle 23 is inserted and pulled out by pressurizing the inside of the pneumatic cylinder 21, but the pressure control valve 1a side is depressurized during insertion or the pressure control valve 1b side is pulled out. Needless to say, the pressure may be reduced.

  From the above, the pressure of the compressed fluid in the pressure control valve body 2 of the pressure control valves 1a and 1b can be easily controlled by controlling the phase difference and frequency of the applied power of the ultrasonic motor 15 by remote operation using the computer 25. Can be adjusted to. In addition, by using the two pressure control valves 1a and 1b having such effects, it is possible to easily operate the puncture needle 23 associated with the pneumatic piston 22 by operating the air pressure, and to generate the MRI apparatus 28. By using the air pressure, the ultrasonic motor 15 and the nonmagnetic puncture needle 23 which are not easily affected by the magnetic field, the puncture operation and the extraction operation of the puncture needle 23 can be performed while using the MRI apparatus 28 in combination. Reference numerals 24 and 27 are sensors for detecting the position of the puncture needle 23 in the power source and the specimen 30. In this embodiment, the computer 25 controls the phase difference and frequency of the applied power. However, the power supply 24 has such a control function, or an apparatus having such a function other than the computer 25. It may be added.

  While using the MRI apparatus, it is possible to perform a puncture operation without causing troubles in an MRI image or an apparatus around the MRI apparatus, and it can be applied to a stereotactic brain operation by remote operation.

(A) is a conceptual diagram of the compression control valve concerning embodiment of this invention, (b) is an AA arrow directional cross-sectional view of Fig.1 (a). FIG. 2 is a detailed view of an ultrasonic motor indicated by reference numeral 15 in FIG. (A) is a conceptual diagram when the rotor is going to rotate counterclockwise, (b) is a conceptual diagram when the rotor is stationary, and (c) is a clockwise diagram of the rotor. It is a conceptual diagram when trying to rotate. It is a conceptual diagram of the pneumatic drive system and puncture system which concern on embodiment of this invention. It is a conceptual diagram of the magnetic resonance imaging apparatus for interventional MRI which concerns on a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1a, 1b ... Pressure control valve 2 ... Pressure control valve main body 3 ... 1st pressure chamber 4 ... 2nd pressure chamber 5 ... 3rd pressure chamber 6 ... Turning wall 6a-6d ... Wall surface 6e ... 1st Partition wall 6f ... second partition wall 7 ... third partition wall 8 ... shaft 9 ... compressed fluid inlet 9a, 9b ... pipe 10 ... compressed fluid opening 11 ... compressed fluid inlet / outlet port 11a ... first flow channel 12 ... compressed fluid Entrance / exit 12a ... Second flow path 13 ... Spring 14 ... Control pressure output port 14a, 14b ... Piping 15 ... Ultrasonic motor 16 ... Case 17 ... Slider 18 ... Bearing 19 ... Stator 20 ... Piezoelectric vibrator 21 ... Pneumatic cylinder 22 ... Pneumatic piston 23 ... Puncture needle 24 ... Power source 25 ... Computer 26 ... Compressor 27 ... Sensor 28 ... MRI device 29 ... Bed 30 ... Sample 30a ... Heads 31a, 31b ... Position information calculation circuit DESCRIPTION OF SYMBOLS 2 ... Gradient magnetic field amplifier 33 ... Receiver 34 ... Transmitter 35 ... Sequencer 36 ... Host computer 37 ... Input device 38 ... Display device 39 ... Memory | storage device 40 ... Probe (RF coil) 41 ... Puncture needle 42a, 42b ... Position sensor 43 ... Gantry 44 ... Static magnetic field magnet 45 ... Gradient magnetic field coil F ₁ ... Force that pushes wall surface 6a F ₂ ... Force that pushes wall surface 6d F _m ... Torque generated by ultrasonic motor F ... Inertial force of rotating wall F _s ... Spring 13 Restoring force φ: Phase difference of applied power φ ₁ : Phase difference of applied power to pressure control valve 1 a φ ₂ : Phase difference of applied power to pressure control valve 1 b f: Frequency of applied power f ₁ : Pressure control valve 1 a Frequency of applied power f ₂ ... Frequency of applied power to pressure control valve 1b

Claims (3)

A pressure control valve body formed in a cylindrical shape, and a first pressure chamber and a second pressure chamber which are accommodated in the pressure control valve body so as to be rotatable by an ultrasonic motor and are divided into a first pressure chamber and a second pressure chamber. A rotating wall comprising one partition and a second partition, a third partition partitioning the first pressure chamber partitioned into the pressure control valve body into a first pressure chamber and a third pressure chamber, An elastic body that connects the third partition wall and the first partition wall, an inlet port that is connected to a third pressure chamber in the pressure control valve body and introduces a compressed fluid, and a first body in the pressure control valve body. An open port for discharging compressed fluid to the outside connected to the second pressure chamber, a first flow path connected to the pressure control valve body, and communication between the first flow path and the first pressure chamber. And a control pressure output port that is connected to the second flow path and supplies pressure by the compressed fluid. , The pressure control valve first flow path, characterized in that connected to the second pressure chamber or the third pressure chamber of the pressure control valve body by the rotation of the second partition wall. The pressure control valve according to claim 1, a compressed fluid supply unit that supplies a compressed fluid to an introduction port of the pressure control valve, and the compressed fluid supplied from a control pressure output port of the pressure control valve. A pneumatic drive system comprising a pneumatic piston and a pneumatic cylinder containing the pneumatic piston. A puncture system, wherein a non-magnetic puncture needle is provided on the pneumatic piston of the pneumatic drive system according to claim 2.