JP6240132B2 - Injection device and method for controlling ultrasonic motor - Google Patents

Description

  The present invention relates to an injection device for injecting a chemical solution, an injection device that includes an ultrasonic motor, and that can release the fixation between a stator and a rotor of the ultrasonic motor, and an ultrasonic motor control method.

  Conventionally, as a medical injection device for injecting a medical solution such as a contrast agent, an injection device including an ultrasonic motor made of a nonmagnetic material has been known (Patent Document 1). Since this injection apparatus does not suffer from magnetic field lines, it can be used together with an apparatus using magnetism such as MRI.

JP-A-5-84296

  In such an injection device, the stator and rotor of the ultrasonic motor are always in pressure contact. For this reason, the stator and the rotor may adhere to each other when the ultrasonic motor is stopped. In particular, in a humid environment, sticking is more likely to occur than in a normal environment. And if a stator and a rotor adhere, it will become impossible to drive an ultrasonic motor. As a result, there is a possibility that the chemical solution cannot be injected.

In order to solve the above problems, an injection device according to the present invention is an injection device for injecting a chemical solution, and includes a shaft and first and second ultrasonic motors fixed to the shaft. An ultrasonic motor unit, and a driving mechanism driven by the ultrasonic motor unit so as to send out the chemical solution when the first and second ultrasonic motors rotate forward, the first and second Each of the ultrasonic motors has a stator and a rotor, and an external connection connector is provided corresponding to each of the first and second ultrasonic motors .

Thereby, even when one ultrasonic motor has adhered, a shaft can be rotated by the other ultrasonic motor. As a result, the rotational force of the other ultrasonic motor is transmitted to the one ultrasonic motor via the shaft, so that the sticking of the one ultrasonic motor can be released .

  An ultrasonic motor control method according to the present invention is an ultrasonic motor control method that is provided in an ultrasonic motor unit that drives a drive mechanism, and that includes a stator and a rotor, and the stator and the rotor are fixed to each other. In order to cancel, the ultrasonic motor is controlled to repeat forward rotation and reverse rotation alternately.

  Thereby, since the fixation of the stator and rotor of the ultrasonic motor can be efficiently released, the driving of the ultrasonic motor can be maintained. Furthermore, by controlling to automatically release the sticking, the process of determining the sticking can be omitted, and the user can save the trouble of releasing the sticking.

  Further features of the present invention will become apparent from the following description of embodiments, given by way of example with reference to the accompanying drawings.

It is a block diagram of an injection | pouring apparatus. It is a schematic perspective view of an injection head. It is a general | schematic expanded view of an ultrasonic motor part. It is a schematic sectional drawing of an ultrasonic motor part. It is a flowchart for demonstrating the control method which concerns on 1st Embodiment. It is a block diagram of the injection apparatus which concerns on 2nd Embodiment and 3rd Embodiment. It is a flowchart for demonstrating the control method which concerns on 2nd Embodiment. It is a flowchart for demonstrating the control method which concerns on 3rd Embodiment. It is a block diagram of the injection apparatus which concerns on 4th Embodiment.

  Hereinafter, exemplary embodiments for carrying out the present invention will be described in detail with reference to the drawings. However, dimensions, materials, shapes, relative positions of components, and the like described in the following embodiments are arbitrary and can be changed according to the configuration of the apparatus to which the present invention is applied or various conditions. Unless otherwise specified, the scope of the present invention is not limited to the embodiments specifically described in the examples described below.

  FIG. 1 is a block diagram of an injection device 1 of this embodiment, and FIG. 2 is a schematic perspective view of an injection head 2 of this embodiment. The injection head 2 can be attached to a stand (not shown) or a ceiling suspension device (not shown). 2 shows the injection head 2 in a state in which a part of the frame 21 is removed for convenience of explanation.

  As shown in FIG. 1, an injection device 1 for injecting a chemical liquid includes an ultrasonic motor unit 3 having an ultrasonic motor 31 and an ultrasonic motor so as to send out the chemical liquid when the ultrasonic motor 31 rotates forward. A drive mechanism 4 driven by the unit 3 and a control device 5 for controlling the ultrasonic motor 31 of the ultrasonic motor unit 3 are provided. The drive mechanism 4 and the ultrasonic motor unit 3 are stored in the frame 21 of the injection head 2 of the injection device 1. The frame 21 has two syringe holders 92 for holding the two cylinders 91. Further, the injection device 1 has a console 6 including a display 53 on which the state of injection of the chemical solution is displayed. The console 6 is connected to the control device 5 via an optical cable, and the control device 5 is connected to the injection head 2. In this way, by connecting the console 6 and the control device 5 via the optical cable, it is possible to reduce adverse effects due to noise. The control device 5 and the console 6 are connected to an external power source inside or outside the examination room, and the control device 5 also functions as a power supply.

The control device 5 includes a CPU 51 for controlling the ultrasonic motor unit 3, a drive circuit 52 for applying a voltage to the ultrasonic motor unit 3, and a timer 54 for measuring the rotation time of the ultrasonic motor 31 or the injection time of the chemical solution. And have. The CPU 51 is electrically connected to the drive circuit 52 in order to transmit a drive signal to the ultrasonic motor unit 3, and the drive circuit 52 is electrically connected to the ultrasonic motor unit 3. An encoder 39 is connected to the ultrasonic motor unit 3, and transmits information such as the number of rotations of the ultrasonic motor 31 and the presence / absence of rotation to the control device 5. Further, when the side on which the syringe holder 92 is located in the frame 21 is the front side, the ultrasonic motor unit 3 is disposed on the rear side portion.

  The drive mechanism 4 is disposed between the syringe holder 92 and the ultrasonic motor unit 3. The drive mechanism 4 includes a transmission mechanism 41 connected to the shaft 35 of the ultrasonic motor unit 3, a ball screw shaft 411 connected to the transmission mechanism 41, a ball screw nut 412 attached to the ball screw shaft 411, And an actuator 413 connected to the screw nut 412. The ball screw nut 412 is screwed into an intermediate portion of the ball screw shaft 411. The transmission mechanism 41 transmits the rotation from the ultrasonic motor unit 3 to the ball screw shaft 411. Further, the transmission mechanism 41 has a pinion gear connected to the shaft 35 and a screw gear connected to the ball screw shaft 411. Therefore, the rotation of the shaft 35 of the ultrasonic motor unit 3 is transmitted to the ball screw shaft 411 via the pinion gear and the screw gear. Thereby, the ball screw shaft 411 rotates according to the transmitted rotation. The ball screw nut 412 slides in the forward direction (front side direction) or the reverse direction (rear side direction) as the ball screw shaft 411 rotates. As a result, the actuator 413 moves forward or backward as the ball screw nut 412 slides. That is, when the shaft 35 rotates forward, the actuator 413 moves forward, and when the shaft 35 rotates reversely, the actuator 413 moves backward.

  When injecting a chemical solution, a cylinder 91 filled with the chemical solution is mounted on the syringe holder 92. A piston 93 that can slide in the cylinder 91 is attached to the cylinder 91. The cylinder 91 is mounted so that the rod of the piston 93 is in contact with the tip of the actuator 413. Accordingly, when the ball screw nut 412 slides in the forward direction with the cylinder 91 mounted, the actuator 413 pushes the piston 93 in the forward direction. When the piston 93 moves forward, the chemical solution in the cylinder 91 is pushed out and injected into the patient's body through a catheter or the like connected to the tip of the cylinder 91. When the ball screw nut 412 slides in the reverse direction, the actuator 413 pulls the piston 93 in the reverse direction.

  When injecting a chemical solution, the user mounts the cylinder 91 on the syringe holder 92 and turns on the power of the injection device 1. Thereafter, when the display 53 is a touch panel, the user presses an injection button displayed on the touch panel. Moreover, when the operation part is provided in the injection | pouring head 2, the user can also press the injection | pouring button of an operation part. When the injection button is pressed, the control device 5 sends a normal rotation signal as a drive signal to the ultrasonic motor unit 3. The ultrasonic motor 31 in the ultrasonic motor unit 3 is driven according to the normal rotation signal, and the shaft 35 rotates in the normal direction. When the shaft 35 rotates forward, the encoder 39 detects rotation and sends a pulse signal to the control device 5. When the injection is completed and the cylinder 91 is removed, the control device 5 sends a reverse rotation signal as a drive signal to the ultrasonic motor unit 3 in order to move the piston 93 backward. In response to the reverse signal, the ultrasonic motor 31 in the ultrasonic motor unit 3 is driven, and the shaft 35 is reversely rotated. The drive signal transmitted to the ultrasonic motor unit is an AC signal, and when one of the two types of signals having different phases is delayed with respect to the other, the other is set to one. When it is late, it becomes a reverse signal.

The control device 5 stores an injection protocol in advance, and the injection of the chemical solution is automatically performed according to the injection protocol. In addition, a medical medium can be injected according to the injection protocol read from the storage medium by inserting a storage medium storing the injection protocol into the control device 5. During normal control according to the injection protocol, a normal voltage within a preset range is applied from the drive circuit 52 to the ultrasonic motor unit 3. In this injection protocol, for example, an injection time, an injection speed, an injection amount, and an injection pressure limit value are set. Since the contents of the injection protocol are displayed on the display 53, the user can check the contents of the injection protocol. The control device 5 controls the injection time using the timer 54. Furthermore, the control device 5 monitors the injection state, and automatically stops the injection of the chemical liquid when an abnormality such as a decrease in the injection pressure is detected. This injection pressure can be detected by a load cell provided at the tip of the actuator 413.

  In addition, although the control apparatus 5 and the console 6 were independent in FIG. 1, the control apparatus 5 and the console 6 can also be integrated. Moreover, although the control apparatus 5 was arrange | positioned outside the flame | frame 21 of the injection | pouring head 2, it can also be arrange | positioned in the flame | frame 21. FIG. Furthermore, the control device 5 and the console 6 can be integrated with the injection head 2. Further, the control device 5 and the console 6 can communicate using wireless communication or infrared communication.

  FIG. 3 is a schematic development view of the ultrasonic motor unit 3 of the present embodiment, and FIG. 4 is a central sectional view of the ultrasonic motor unit 3.

  As shown in FIG. 3, the ultrasonic motor unit 3 of the present embodiment includes a plurality of ultrasonic motors 31 having the same structure and arranged so as to be substantially symmetrical. That is, the ultrasonic motor unit 3 includes a first ultrasonic motor 311 and a second ultrasonic motor 312 that is coaxial with the first ultrasonic motor 311. The ultrasonic motor unit 3 includes a shaft 35 that penetrates the first ultrasonic motor 311 and the second ultrasonic motor 312, and a case 34 to which the pair of bases 341 are fixed. Each of the pair of bases 341 has a plate shape and is fixed to the case 34 with screws. The first ultrasonic motor 311 and the second ultrasonic motor 312 are stored in a substantially cylindrical space in the case 34. The first ultrasonic motor 311 and the second ultrasonic motor 312 have a disk-shaped stator 32 and a rotor 33, respectively. The first ultrasonic motor 311 and the second ultrasonic motor 312 are stored in the case 34 while being sandwiched between the pair of bases 341. A terminal support plate 344 on which a connector for connecting to the outside is mounted is attached to the pair of bases 341 by screws.

The stator 32 includes a piezoelectric element 322 such as a piezoelectric element, an elastic body 323, and a sliding member 324 from the base 341 side toward the rotor 33 side. The piezoelectric element 322 and the sliding material 324 are bonded to the elastic body 323. In addition, a flexible substrate 36 is bonded to the stator 32, and both are electrically connected. When a high-frequency voltage is applied to the piezoelectric element 322 via the flexible substrate 36, the elastic body 323 is flexibly vibrated by the expansion and contraction of the piezoelectric element 322, and a traveling wave is generated in the circumferential direction. Since the rotor 33 is in contact with the elastic body 323 via the sliding member 324, when a traveling wave is generated, the rotor 33 rotates in a direction opposite to the traveling wave. With this rotation, the shaft 35 rotates in the same direction as the rotor 33. In the present embodiment, the rotation of the rotor 33 when pushing out the chemical solution is referred to as normal rotation, and the rotation of the rotor 33 in the direction opposite to the normal rotation direction is referred to as reverse rotation. For example, the rotation of the rotor 33 when the actuator 413 is advanced is normal rotation. The rotation of the rotor 33 when the actuator 413 is moved backward is reverse rotation. The piezoelectric element 322 is applied with a normal voltage in a predetermined range during normal control according to the injection protocol.

  As shown in FIG. 4, the stator 32 is fixed to the base 341 by screws 321, and the rotor 33 is fixed to the collar 351 of the shaft 35 by screws. A hole through which the shaft 35 passes is formed in the base 341, and a bush 343 is attached to the hole by press-fitting. The bush 343 functions as a bearing for the shaft 35, and both ends of the shaft 35 penetrate the bush 343. Further, the rotor 33 of the first ultrasonic motor 311 and the second ultrasonic motor 312 has a disc spring portion 332 having a disk shape. The disc spring portion 332 functions as a spring for biasing the rotor 33 against the stator 32. Further, the rotor 33 has a base portion 333 that contacts the sliding body 324 of the stator 32. A disc spring portion 332 is provided between the base portion 333 and the center of the rotor 33. The disc spring portion 332 biases the base portion 333 against the stator 32, so that the rotor 33 comes into close contact with the stator 32. Thereby, since it is not necessary to provide a separate spring for bringing the rotor 33 and the stator 32 into close contact with each other, the size of the ultrasonic motor unit 3 can be reduced.

  As is clear from FIG. 3, the rotor 33 of the first ultrasonic motor 311 is disposed so as to face the rotor 33 of the second ultrasonic motor 312. That is, the first ultrasonic motor 311 and the second ultrasonic motor 312 are arranged substantially symmetrically with the flange 351 of the shaft 35 interposed therebetween. A disc-shaped washer, for example, is disposed as the spacer 37 between the first ultrasonic motor 311 and the second ultrasonic motor 312 and the flange 351 of the shaft 35. Thereby, by increasing / decreasing the thickness of the spacers 37 or the number of the spacers 37, the pressing force of the rotor 33 against the stator 32 can be easily increased / decreased. Specifically, the pressing force of the rotor 33 can be increased by increasing the number of the spacers 37. If the rotor 33 and the stator 32 are sufficiently in close contact with each other, the spacer 37 may not be disposed.

  Thus, the rotors 33 of the first ultrasonic motor 311 and the second ultrasonic motor 312 are opposed to each other. Therefore, in this embodiment, the size of the ultrasonic motor unit 3 can be reduced as compared with the case where the rotor 33 of the first ultrasonic motor 311 and the rotor 33 of the second ultrasonic motor 312 are directed in the same direction. . That is, if the rotor 33 and the stator 32 are disposed so as to face each other, it is necessary to provide two collars 351 corresponding to the respective rotors 33 of the two ultrasonic motors 31. Furthermore, it is necessary to provide an additional base for fixing the stator 32 in the case 34. As a result, the size of the ultrasonic motor unit 3 is increased. On the other hand, according to the present embodiment, the rotors 33 of the first ultrasonic motor 311 and the second ultrasonic motor 312 can be disposed on both sides of one collar 351. Further, it is not necessary to provide the base 341 for fixing the stator 32 in the case 34. Therefore, the size of the ultrasonic motor unit 3 can be reduced.

  Further, according to the ultrasonic motor unit 3 of the present embodiment, the torque can be increased by having two ultrasonic motors 31 as compared with the case of having only one ultrasonic motor 31. Therefore, the chemical solution can be injected at a high pressure or at a high speed. Further, the rotor 33 of the first ultrasonic motor 311 and the second ultrasonic motor 312 is fixed to one shaft 35. Therefore, even when one ultrasonic motor 31 is stuck, the shaft 35 can be rotated by the other ultrasonic motor 31. As a result, the rotational force of the other ultrasonic motor 31 is transmitted to one ultrasonic motor 31 via the shaft 35. Thereby, the adhesion of one ultrasonic motor 31 can be released.

  In the present embodiment, the injection head 2 and the control device 5 are configured using a non-magnetic material so that they can be placed in the examination room. Specifically, it is configured using stainless steel, aluminum, plastic, brass, copper, ceramics, or the like. Furthermore, the console 6 arranged in the operation room can also be arranged in the examination room by using a non-magnetic material. The ultrasonic motor unit 3 is also configured using a nonmagnetic material. Specifically, the material of the elastic body 323 is phosphor bronze, the material of the shaft 35, the screw 321 and the spacer 37 is brass, the material of the case 34, the base 341 and the rotor 33 is aluminum, and the material of the bush 343 Is a fluororesin. Thereby, the injection device 1 can be used in the vicinity of a device using magnetism, such as an MRI (Magnetic Resonance Imaging) device. However, when installing sufficiently away from the MRI apparatus, or when a magnetic shield process is performed, the injection head 2 or the control apparatus 5 can be configured using a magnetic material. The injection device 1 can also be used with devices such as a CT (Computed Tomography) scanner, a PET (Positron Emission Tomography) device, a CT angiography device, an MR angiography device, and an angiography device. In this case, the injection head 2 or the control device 5 can be configured using a magnetic material.

  Moreover, the Example mentioned above is an example, for example, the injection apparatus 1 can also be used for the piston 93 which does not have a rod. Furthermore, the injection device 1 can be configured so that only one or three or more cylinders 91 can be mounted. In this case, the number of ultrasonic motor units 3 and drive mechanisms 4 corresponding to the number of cylinders 91 that can be mounted are provided in the injection device 1. Further, the transmission mechanism 41 is not limited to a configuration having a pinion gear and a screw gear, and various configurations can be adopted as necessary. For example, the transmission mechanism 41 can be configured to include a pulley and a belt, a rack and a pinion gear, or a plurality of gears combined with each other. Further, the shaft 35 of the ultrasonic motor unit 3 can be directly connected to the drive mechanism 4. In addition, the ultrasonic motor unit 3 may include only one or three or more ultrasonic motors 31.

[First Embodiment]
FIG. 5 is a flowchart illustrating a method for controlling the ultrasonic motor 31 according to the first embodiment. As described above, the control device 5 is the ultrasonic motor 31 provided in the ultrasonic motor unit 3 that drives the drive mechanism 4, and controls the ultrasonic motor 31 having the stator 32 and the rotor 33. In order to release the fixation between the stator 32 and the rotor 33 of the ultrasonic motor 31, in the first embodiment, the ultrasonic motor 31 is controlled to alternately repeat forward rotation and reverse rotation. That is, the control device 5 controls the ultrasonic motor 31, that is, the first ultrasonic motor 311 and the second ultrasonic motor 312 to repeat normal rotation and reverse rotation. The control method of the first embodiment will be described below according to the flowchart.

  When the power is turned on to the injection device 1, the control device 5 sends a normal rotation signal to the ultrasonic motor unit 3 and controls the ultrasonic motor 31 to rotate normally (S11). At this time, the control device 5 does not determine whether sticking has occurred. Thereafter, the control device 5 sends a reverse signal to the ultrasonic motor unit 3 and controls the ultrasonic motor 31 to reverse (S12). The normal rotation or reverse rotation time is, for example, 10 to 50 msec, and a stop time of, for example, about 10 to 50 msec is provided between the normal rotation and the reverse rotation. The forward rotation time, reverse rotation time, and stop time can all be set to the same length. Therefore, normal rotation and reverse rotation are repeated every tens of msec. Moreover, after performing normal rotation and reverse rotation, a predetermined stop time of, for example, about 0.5 seconds to 1 second can be provided before performing the next normal rotation and reverse rotation. That is, when the operation of stopping after the ultrasonic motor 31 has been rotated forward and then stopped again after being reversed is defined as one operation, a predetermined stop time is required until the next operation (forward rotation) is started. Can be provided.

At the time of forward rotation and reverse rotation, a normal voltage having the same height as that of a predetermined normal control is applied to the ultrasonic motor 31. Then, after repeating the forward rotation and the reverse rotation a plurality of times, when the shaft 35 rotates, the encoder 39 transmits a pulse signal to the control device 5. When the control device 5 receives the pulse signal (YES in S13), since the sticking has been released or no sticking has occurred, the control device 5 ends the sticking release control. Thereafter, the control device 5 starts normal control according to the injection protocol in accordance with the user's operation. On the other hand, when the sticking has occurred and the sticking is not released by the sticking release control, the shaft 35 does not rotate. Therefore, the encoder 39 does not transmit a pulse signal to the control device 5 (NO in S13). In this case, the control device 5 determines whether or not a predetermined time has elapsed from the start of the sticking release control (S14). If the controller 5 determines that the predetermined time has not elapsed (NO in S14), since the sticking has occurred and the sticking has not been released, the process returns to S11 and the sticking release control is continued. As a result, the control device 5 performs control so that the ultrasonic motor 31 repeats forward rotation and reverse rotation a plurality of times within a preset time. Here, the predetermined time is set in advance and is, for example, in the range of 5 to 60 seconds. On the other hand, when determining that the predetermined time has elapsed (YES in S14), the control device 5 displays an error message on the display 53 (S15), and ends the sticking release control. In this case, the control device 5 starts normal control after the user releases the fixation.

  According to the first embodiment, by repeatedly performing normal rotation and reverse rotation within a predetermined time, it is possible to repeatedly apply forces from the normal rotation direction and the reverse rotation direction to the stator 32 and the rotor 33 of the ultrasonic motor 31. Thereby, fixation of stator 32 and rotor 33 can be canceled effectively. Further, the control device 5 performs the sticking release control of the ultrasonic motor 31 before or without making a judgment as to whether or not the sticking has occurred. In this way, since the control device 5 automatically performs the sticking release control, it is not necessary for the user to release the sticking after the sticking occurs. Furthermore, when the sticking is automatically released, the step of the controller 5 determining the sticking can be omitted.

[Second Embodiment]
FIG. 6 is a block diagram of the injection device 1 according to the second embodiment, and FIG. 7 is a flowchart illustrating a method for controlling the ultrasonic motor 31 according to the second embodiment. Unlike the first embodiment, the control device 5 according to the second embodiment allows the ultrasonic motor 31 to perform normal rotation and reverse rotation in a state where a voltage higher than a preset normal voltage is applied to the ultrasonic motor 31. Control to repeat. Therefore, the injection device 1 of the second embodiment further includes a booster circuit 55. In addition, about the same structure as 1st Embodiment, the same referential mark shall be attached | subjected and the description is abbreviate | omitted.

  As shown in FIG. 6, the control device 5 of the injection device 1 according to the second embodiment is provided with a booster circuit 55 electrically connected to the ultrasonic motor unit 3. The control device 5 can switch between driving by the driving circuit 52 and driving by the booster circuit 55. Here, switching of the circuit is performed according to a program stored in the control device 5 in advance. Or it is good also as a structure which can switch a circuit according to a user's operation. Hereinafter, the control method of the second embodiment will be described with reference to the flowchart of FIG.

When the power is turned on to the injection device 1, the control device 5 switches from driving by the driving circuit 52 to driving by the boosting circuit 55, and boosts the voltage applied to the ultrasonic motor 31 (S21). Then, a normal rotation signal is sent to the ultrasonic motor unit 3 to control the ultrasonic motor 31 to rotate normally (S22). Thereafter, the control device 5 sends a reverse signal to the ultrasonic motor unit 3 to control the ultrasonic motor 31 to reverse (S23). When the shaft 35 rotates after repeating the forward rotation and the reverse rotation a plurality of times, the encoder 39 transmits a pulse signal to the control device 5. When the control device 5 receives the pulse signal (YES in S24), the sticking release control is terminated because the sticking has been released or no sticking has occurred. Thereafter, the control device 5 switches (steps down) to driving by the driving circuit 52 and starts normal control in accordance with the operation of the user.

  When the sticking occurs and the sticking is not released by the sticking release control, the shaft 35 does not rotate. Therefore, the encoder 39 does not transmit a pulse signal to the control device 5 (NO in S24). In this case, the control device 5 determines whether or not a predetermined time has elapsed from the start of the sticking release control (S25). If the controller 5 determines that the predetermined time has not elapsed (NO in S25), since the sticking has occurred and the sticking has not been released, the process returns to S22 and the sticking release control is continued. On the other hand, when it is determined that the predetermined time has elapsed (YES in S25), the control device 5 displays an error message on the display 53 (S26) and ends the sticking release control. In this case, the control device 5 starts normal control after the user releases the fixation.

Also in the second embodiment, by repeatedly performing normal rotation and reverse rotation within a predetermined time, forces from the normal rotation direction and the reverse rotation direction can be repeatedly applied to the stator 32 and the rotor 33 of the ultrasonic motor 31. Thereby, fixation of stator 32 and rotor 33 can be canceled effectively. Further, when the sticking is automatically released, it is not necessary for the user to release the sticking after the sticking occurs, and the step of the controller 5 determining the sticking can be omitted. In addition, the driving torque of the ultrasonic motor 31 can be increased by applying a high voltage. Thereby, since the force stronger than 1st Embodiment can be applied to the stator 32 and the rotor 33, fixation can be cancelled | released more effectively.

[Third Embodiment]
FIG. 8 is a flowchart illustrating a method for controlling the ultrasonic motor 31 according to the third embodiment. Unlike the second embodiment, the control device 5 of the third embodiment has a voltage higher than the normal voltage after the ultrasonic motor 31 repeats normal rotation and reverse rotation in a state where a preset normal voltage is applied. Is applied to the ultrasonic motor 31, and the ultrasonic motor 31 is controlled to repeat normal rotation and reverse rotation. Therefore, the injection device 1 of the third embodiment includes a booster circuit 55 as in the second embodiment. The control method of the third embodiment will be described below according to the flowchart.

When the power is turned on to the injection device 1, the control device 5 sends a normal rotation signal to the ultrasonic motor unit 3 and controls the ultrasonic motor 31 to rotate normally (S31). Thereafter, the control device 5 sends a reverse signal to the ultrasonic motor unit 3 and controls the ultrasonic motor 31 to reverse (S32). During the first forward rotation and reverse rotation, the normal voltage having the same preset height as that during the normal control is applied to the ultrasonic motor 31. When the shaft 35 rotates after repeating the forward rotation and the reverse rotation a plurality of times, the encoder 39 transmits a pulse signal to the control device 5. When the control device 5 receives the pulse signal (YES in S33), the sticking release control is terminated because the sticking has been released or no sticking has occurred. Thereafter, the control device 5 starts normal control according to the injection protocol in accordance with the user's operation.

When the sticking occurs and the sticking is not released by the sticking release control, the shaft 35 does not rotate. Therefore, the encoder 39 does not transmit a pulse signal to the control device 5 (NO in S33). In this case, the control device 5 determines whether or not a predetermined time has elapsed from the start of the sticking release control (S34). When the control device 5 determines that the predetermined time has not elapsed (NO in S34), since the sticking has occurred and the sticking has not been released, the process returns to S31 and the sticking release control is continued. On the other hand, when it is determined that the predetermined time has elapsed (YES in S34), the control device 5 switches from driving by the driving circuit 52 to driving by the boosting circuit 55 and boosts the second forward rotation and reverse rotation. Therefore, the voltage applied to the ultrasonic motor 31 is boosted (S35). Here, the predetermined time is set in advance and is, for example, in the range of 5 to 60 seconds. Then, the control device 5 sends a normal rotation signal to the ultrasonic motor unit 3 and controls the ultrasonic motor 31 to rotate normally (S36). Thereafter, the control device 5 sends a reverse signal to the ultrasonic motor unit 3 and controls the ultrasonic motor 31 to reverse (S37).

  After the second forward rotation and reverse rotation are repeated a plurality of times, the encoder 39 transmits a pulse signal to the control device 5 when the shaft 35 rotates. When the control device 5 receives the pulse signal (YES in S38), since the sticking is released, the sticking release control is terminated. Thereafter, the control device 5 switches (steps down) to driving by the driving circuit 52 and starts normal control in accordance with the operation of the user. On the other hand, since the shaft 35 does not rotate when the fixation is not released, the encoder 39 does not transmit a pulse signal to the control device 5 (NO in S38). In this case, the control device 5 determines whether or not a predetermined time has elapsed since the start of the sticking release control (S39). If the control device 5 determines that the predetermined time has not elapsed (NO in S39), the control device 5 returns to S36 and continues the sticking release control because the sticking has not been released. The predetermined time here is also set in advance, for example, in the range of 5 to 60 seconds. On the other hand, when determining that the predetermined time has elapsed (YES in S39), the control device 5 displays an error message on the display 53 (S40), and ends the sticking release control. In this case, the control device 5 starts normal control after the user releases the fixation.

Also in the third embodiment, by repeatedly performing normal rotation and reverse rotation within a predetermined time, it is possible to repeatedly apply forces from the normal rotation direction and the reverse rotation direction to the stator 32 and the rotor 33 of the ultrasonic motor 31. Thereby, fixation of stator 32 and rotor 33 can be canceled effectively. Further, when the sticking is automatically released, it is not necessary for the user to release the sticking after the sticking occurs, and the step of the controller 5 determining the sticking can be omitted. In addition, when the fixation cannot be released, the second forward rotation and the reverse rotation are repeated with a high voltage applied . Thereby, since the force stronger than 1st Embodiment can be applied to the stator 32 and the rotor 33, fixation can be cancelled | released more effectively.

  In the second embodiment and the third embodiment, the booster circuit 55 is provided in the control device 5. However, the booster circuit 55 can also be provided in the console 6. The booster circuit 55 can also be provided in the injection head 2.

[Fourth Embodiment]
FIG. 9 is a block diagram of the injection device 1 according to the fourth embodiment. The injection device 1 of the fourth embodiment also includes an ultrasonic motor unit 3 having an ultrasonic motor 31, a drive mechanism 4 driven by the ultrasonic motor unit 3, and a control device 5 that controls the ultrasonic motor unit 3. Prepare. Unlike the above embodiments, the drive mechanism 4 of the fourth embodiment includes a peristaltic finger mechanism 415, and the peristaltic finger mechanism 415 is connected to a transmission mechanism 42 connected to the shaft 35 of the ultrasonic motor 31. In addition, about the same structure as said each embodiment, the same referential mark shall be attached | subjected and the description is abbreviate | omitted.

  In the fourth embodiment, the control device 5 is arranged in the frame 21. The control device 5 has a drive circuit 52 and is electrically connected to the ultrasonic motor unit 3 in order to transmit a drive signal. The frame 21 has a tube holder 96, and the tube holder 96 holds a tube 95 through which a chemical solution flows. Further, the drive mechanism 4 includes a transmission mechanism 42 that transmits the rotation from the ultrasonic motor unit 3, and a peristaltic finger mechanism 415 connected to the transmission mechanism 42. The transmission mechanism 42 has a pulley and a belt. Therefore, the rotation of the shaft 35 of the ultrasonic motor unit 3 is transmitted to the peristaltic finger mechanism 415 via the pulley and the belt. When the shaft 35 rotates normally, the peristaltic finger mechanism 415 rotates normally according to the transmitted rotation. Here, since the tube 95 is made of a flexible material such as highly elastic vinyl chloride, it has a property of being restored even when pressed. Therefore, when the peristaltic finger mechanism 415 rotates forward, the tube 95 is sequentially pressed, and the chemical solution in the tube 95 is pushed out. And it inject | pours into a patient's body through the catheter etc. which are connected to the front-end | tip of the tube 95. FIG. In the fourth embodiment, the rotation of the rotor 33 of the ultrasonic motor 31 when pushing out the chemical solution is referred to as normal rotation, and the rotation of the rotor 33 in the direction opposite to the normal rotation direction is referred to as reverse rotation.

  Also in the fourth embodiment, the sticking release control of each of the above embodiments can be performed. Therefore, by repeatedly performing normal rotation and reverse rotation within a predetermined time, it is possible to repeatedly apply forces from the normal rotation direction and the reverse rotation direction to the stator 32 and the rotor 33 of the ultrasonic motor 31. Thereby, fixation of stator 32 and rotor 33 can be canceled effectively. Further, since the control device 5 automatically performs the sticking release control, it is not necessary for the user to release the sticking after the sticking occurs. Furthermore, when the sticking is automatically released, the step of the controller 5 determining the sticking can be omitted.

  While the present invention has been described with reference to the embodiments, the present invention is not limited to the above embodiments. Inventions modified within the scope not departing from the present invention and inventions equivalent to the present invention are also included in the present invention. Moreover, each embodiment and modification can be combined suitably in the range which is not contrary to this invention.

  For example, in the sticking release control of each of the above embodiments, the reverse rotation is performed after the normal rotation, but the normal rotation may be performed after the reverse rotation. Even in this case, forces from the forward direction and the reverse direction can be repeatedly applied to the stator 32 and the rotor 33 of the ultrasonic motor 31. Thereby, fixation of stator 32 and rotor 33 can be canceled effectively. Further, the sticking release control can be performed at a timing other than the timing when the power is supplied to the injection device 1. For example, the sticking release control can be performed at the timing when the drive signal is transmitted to the ultrasonic motor unit 3. In this case, the sticking release control is performed before the driving (forward rotation or reverse rotation) of the ultrasonic motor 31 is started. Furthermore, the sticking release control can be performed according to the operation by the user. In this case, a configuration in which a sticking release button is provided on the operation unit of the injection head 2 or a configuration in which the sticking release button is displayed on the touch panel can be employed. Further, the sticking release control can be performed when the actuator 413 is moved backward, that is, at the timing when the reverse rotation signal is sent to the ultrasonic motor unit 3.

  Further, in the sticking release control of each of the above embodiments, it is determined whether or not to display an error message depending on whether or not a predetermined time has elapsed. However, it is also possible to determine whether or not to display an error message depending on whether or not the number of forward and reverse rotations of the ultrasonic motor 31 has reached a predetermined number. Furthermore, the injection device 1 of the present invention is not limited to a configuration connected to an external power supply, and may employ a configuration using a wireless power supply or a configuration including an internal power supply such as a battery.

  1: injection device, 3: ultrasonic motor unit, 4: drive mechanism, 5: control device, 31: ultrasonic motor, 32: stator, 33: rotor, 35: shaft, 41: transmission mechanism, 42: transmission mechanism, 411: Ball screw shaft, 412: Ball screw nut, 413: Actuator, 415: Peristaltic finger mechanism

Claims (9)

An injection device for injecting a chemical solution,
An ultrasonic motor unit having one shaft and first and second ultrasonic motors fixed to the shaft;
A drive mechanism driven by the ultrasonic motor unit so as to send out the chemical liquid when the first and second ultrasonic motors rotate forward,
The first and second ultrasonic motors each have a stator and a rotor,
An injection device, wherein an external connection connector is provided corresponding to each of the first and second ultrasonic motors. Each of the first and second ultrasonic motors has a piezoelectric element,
The external connection connector is mounted on a terminal support plate,
The injection device according to claim 1, wherein the terminal support plate is connected to a substrate, and a voltage is applied to the piezoelectric element through the substrate. A control device for controlling the first and second ultrasonic motors;
3. The injection according to claim 1, wherein the control device controls the first and second ultrasonic motors to repeat normal rotation and reverse rotation a plurality of times within a preset time. machine. A control device for controlling the first and second ultrasonic motors;
The control device repeats forward and reverse rotations of the first and second ultrasonic motors in a state where a voltage higher than a preset normal voltage is applied to the first and second ultrasonic motors. The injection device according to claim 1, wherein the injection device is controlled as follows. A control device for controlling the first and second ultrasonic motors;
After the first and second ultrasonic motors repeat normal rotation and reverse rotation in a state where a preset normal voltage is applied, a voltage higher than the normal voltage is applied to the control device. 3. The injection device according to claim 1, wherein the first and second ultrasonic motors are controlled to repeat normal rotation and reverse rotation while being applied to two ultrasonic motors. A control device for controlling the first and second ultrasonic motors;
The injection device according to claim 1 or 2, wherein the control device controls the first and second ultrasonic motors to repeat normal rotation and reverse rotation after the injection device is powered on. A control device for controlling the first and second ultrasonic motors;
3. The injection device according to claim 1, wherein, even if one of the first and second ultrasonic motors is fixed, the other ultrasonic motor is rotated.   The drive mechanism includes a transmission mechanism connected to the shaft, a ball screw shaft connected to the transmission mechanism, a ball screw nut attached to the ball screw shaft, and an actuator connected to the ball screw nut. 8. Injection device according to any one of the preceding claims, characterized in that it is characterized in that   The injection device according to any one of claims 1 to 7, wherein the drive mechanism includes a transmission mechanism connected to the shaft and a peristaltic finger mechanism connected to the transmission mechanism.

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