KR20200126700A - High intensity focused ultrasound apparatus having function for compensating initial position of piezoelectric member - Google Patents

Abstract

A high-intensity focused ultrasonic device comprises an actuator for generating a driving force, an ultrasonic cartridge configured to generate ultrasonic waves, and a controller for controlling driving of the actuator. The ultrasonic cartridge comprises a housing, a piezoelectric element that is disposed in the housing and causes ultrasonic vibration by application of power, a moving part on which the piezoelectric element is mounted and configured to be movable by a driving force of the actuator, a magnet installed in the moving part to move with the moving part and the piezoelectric element, a magnetic sensor that detects a magnetic field generated by the magnet to generate a signal indicating position information on the position of the piezoelectric element, and a memory for storing a position correction value for correcting the starting position of the piezoelectric element during the ultrasonic generation operation based on the signal from the magnetic sensor. The controller controls the actuator to correct the starting position of the piezoelectric element based on the signal of the magnetic sensor and the position correction value.

Description

High intensity focused ultrasound apparatus having function for compensating initial position of piezoelectric member}

The present invention relates to a high intensity focused ultrasound apparatus.

The basic principle of the high-intensity focused ultrasonic device is to generate high-intensity focused ultrasonic waves by placing and moving an ultrasonic piezoelectric element in a housing filled with an ultrasonic transmission medium. The high-intensity focused ultrasound generated in this way is irradiated into the skin through a delivery medium. Usually, water is used as the ultrasonic transmission medium, and the piezoelectric element is configured to move repeatedly in water using a mechanical mechanism. At this time, a position recognition technology capable of detecting when the piezoelectric element moves once and then comes back to a specific position, that is, a starting position, is essential. If the piezoelectric element is repeatedly moved infinitely without detecting the starting position, the piezoelectric element cannot move between predetermined positions due to an error or failure of a driving device during movement. As one of the methods for recognizing the starting position, a magnetic field generated by a magnet provided to move with a moving piezoelectric element is detected using a magnetic sensor provided outside a housing filled with a transmission medium to recognize the position of a piezoelectric element There is this.

The ultrasonic generator that generates ultrasonic waves is a piezoelectric element that generates ultrasonic waves, a moving part configured to repeatedly move the piezoelectric element, a housing equipped with a piezoelectric element and a moving part and filled with an ultrasonic transmission medium, and attached to the moving part from the outside of the housing It may be composed of a magnetic sensor for detecting the storage of the magnet, a piezoelectric element, and a memory for recording characteristics of the magnetic sensor. In addition, a driving device for driving the moving unit and a control device for controlling the driving device may be separately provided externally.

A driving device outside the ultrasonic generator repeatedly moves the piezoelectric element and the magnet mounted on the moving part inside the housing using a mechanical mechanism, and detects when the piezoelectric element reaches a specific position (start position). In this way, a magnetic sensor provided outside the housing detects whether the piezoelectric element is positioned at the starting position. However, due to factors such as the characteristics of the magnet mounted on the moving part and the magnetic sensor provided outside are individually different, and the relative positions of the magnet and the magnetic sensor located inside the housing are slightly different during manufacturing, a number of ultrasonic generators In the case of manufacturing, when the starting position of the moving part is sensed using a magnetic sensor, an error occurs between the detected starting position and the actual mechanical starting position, which may cause problems during product operation. In particular, when a plurality of ultrasonic generators are alternately connected to the same driving device and used, it is difficult to accurately determine the starting position depending on the ultrasonic generator.

Registered Patent Publication No. 10-1675547 (Registration date: November 7, 2016)

The problem to be solved by the present invention is to provide a technology capable of solving the problem that the piezoelectric element cannot repeatedly move in a desired section because the starting position of the piezoelectric element is not accurately recognized due to the difference in characteristics of the magnet and the magnetic sensor and the installation position error. will be.

The high-intensity focused ultrasound apparatus according to an embodiment of the present invention includes an actuator that generates driving force, an ultrasonic cartridge configured to generate ultrasonic waves, and a controller that controls driving of the actuator. The ultrasonic cartridge is a housing, a piezoelectric element that is disposed in the housing and causes ultrasonic vibration by the application of power, a moving part in which the piezoelectric element is mounted and configured to be movable by a driving force of the actuator, the moving part, and the piezoelectric element. A magnet installed in the moving part to move with the element, a magnetic sensor that detects a magnetic field generated by the magnet to generate a signal indicating positional information on the position of the piezoelectric element, and a signal from the magnetic sensor And a memory for storing a position correction value for correcting a starting position of the piezoelectric element during an ultrasonic generation operation. The controller controls the actuator to correct the starting position of the piezoelectric element based on the signal from the magnetic sensor and the position correction value.

The position correction value may be measured in advance using the ultrasonic cartridge in which the magnet and the magnetic sensor are installed, and then stored in the memory.

The position correction value may be calculated as a value corresponding to a difference between a measurement position of the piezoelectric element and a reference start position measured at a time when a signal of the magnetic sensor is changed according to the movement of the magnet.

When the measurement position is located outside the operation section of the piezoelectric element based on the reference start position, the controller includes the piezoelectric element as much as a value corresponding to the sum of the position correction value and a preset operation distance of the piezoelectric element. The actuator may be controlled to continuously move forward, and the piezoelectric element may start generating ultrasonic waves at a point in time when the forward movement of the piezoelectric element is started by the position correction value during the forward movement of the piezoelectric element. .

When the measurement position is located inside the operation section of the piezoelectric element based on the reference start position, the controller moves the piezoelectric element backward by the position correction value and then moves the actuator forward by a preset operation distance. And control so that the piezoelectric element starts generating ultrasonic waves at a start point of the forward movement of the piezoelectric element.

According to the present invention, the piezoelectric element can generate ultrasonic waves in a predetermined section by accurately correcting the error of the starting position of the piezoelectric element, which may be caused by the difference in characteristics of the magnet and the magnetic sensor of the individual ultrasonic cartridge and the installation position error.

1 is a perspective view of a high intensity focused ultrasound apparatus according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1.
3 is a view showing a state in which the ultrasonic cartridge is separated in FIG. 2.
4 is a block diagram of elements for controlling a start position of a high intensity focused ultrasound apparatus according to an embodiment of the present invention.
5 is a view for explaining a method of determining a position correction value for correction of a starting position of a piezoelectric element of a high intensity focused ultrasound apparatus according to an embodiment of the present invention.
6 is a diagram illustrating a process of controlling movement and operation of the piezoelectric element in the case of FIG. 5.
7 is a view for explaining a method of determining a position correction value for correction of a starting position of a piezoelectric element of a high intensity focused ultrasound apparatus according to another embodiment of the present invention.
8 is a diagram illustrating a process of controlling movement and operation of a piezoelectric element in the case of FIG. 7.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The high-intensity focused ultrasound apparatus according to an embodiment of the present invention is a device that focuses ultrasound and irradiates a body part to perform a predetermined treatment.

1, the high-intensity focused ultrasound apparatus according to an embodiment of the present invention includes a handle 10 formed to be held by hand, and an ultrasonic cartridge 20 detachably fastened thereto. I can.

The handle 10 is formed to be held by a practitioner performing the treatment by hand, and at one side, a connection part for connecting a power line for applying pulse power to the ultrasonic cartridge 20, a communication line for input/output of a control signal, etc. 21) may be provided. For example, a wire (not shown) connected to a power source provided in an external body (not shown) may be connected through the connector 21.

Referring to FIG. 2, the handle 10 may have a case shape forming a space therein, and an actuator 30 that generates a driving force may be provided inside the handle 10. For example, the actuator 30 may be a linear motor that generates a driving force for linear reciprocating motion, and the actuator is hereinafter referred to as a linear motor. For example, the linear motor 30 may include a drive shaft 31 that performs linear reciprocating motion by electromagnetic force, and the drive shaft 31 is configured to perform linear reciprocating motion in a horizontal direction in FIG. 2.

The controller 40 controls the driving of the actuator, that is, the linear motor 30. The controller 40 may be disposed within the handle 10 or may be provided in a separate body. The controller 40 may include a microprocessor, a memory, and related hardware and software for controlling the driving of the linear motor 30, and the microprocessor may be programmed to perform a control process to be described below.

The ultrasonic cartridge 20 may be configured to generate ultrasonic waves by receiving power. The ultrasonic cartridge 20 is configured in the form of a cartridge and may be detachably fastened to the handle 10. For example, when the life of the ultrasonic cartridge 20 is over, remove it and fasten a new ultrasonic cartridge to the handle 10 Thus, ultrasound treatment can be performed. 3 shows a state in which the ultrasonic cartridge 20 is separated from the handle 10, and the ultrasonic cartridge 20 may be assembled to the handle 10 in the direction of the arrow in FIG. 3. The ultrasonic cartridge 20 may be configured to receive pulse power from a power source installed in a separate body and thereby induce ultrasonic vibration.

Referring to FIG. 2, the ultrasonic cartridge 20 includes a housing 21, and a piezoelectric element 22 is movably disposed in the housing 21. The piezoelectric element 22 may be connected to the moving part 24 through the connection member 23, and the moving part 24 is connected to the drive shaft 31 of the linear motor 30 to be connected with the drive shaft 31. It can be configured to make a linear reciprocating movement. As exemplarily shown in FIG. 2, the connection member 23 may include a guide part 231 in a hollow shape, and is inserted into the guide part 231 of the connection member 23 to perform a guide function. A guide rod 25 may be provided. The guide rod 25 extends in the horizontal direction in FIG. 2, whereby the piezoelectric element 22 fastened to the connection member 23 may perform linear reciprocating motion in the horizontal direction in FIG. 2. At this time, the space S in which the piezoelectric element 22 is disposed may be filled with an ultrasonic transmission medium such as water capable of ultrasonic transmission, and a through hole may be provided at the tip of the housing 21 for ultrasonic transmission, and the ultrasonic transmission medium The sealing cover 26 formed of an ultrasonic transmissive material for sealing of the housing 21 may seal the through hole of the housing 21.

The piezoelectric element 22 induces ultrasonic vibration by a pulsed power source, and may include, for example, a piezoelectric ceramic and electrodes formed on both sides thereof. The piezoelectric element 22 is mounted on the moving part 24 through the connecting member 23, and the moving part 24 is linearly reciprocated by the linear motor 30, so that the piezoelectric element 22 is also the housing 21 Linear reciprocating motion in the space (S) of. The piezoelectric element 22 induces ultrasonic vibration when pulse power is applied, and the controller 40 described above may control the application of pulse power for the operation of the piezoelectric element 22.

The moving part 24 may have a shape of a hollow shaft with one end open, and the insertion rod 27 fixed to the inner surface of the housing 31 is inserted into the open hollow of the moving part 24 to thereby move the moving part ( 24) movement can be guided.

Meanwhile, FIG. 2 shows a state in which the drive shaft 31 and the moving part 24 of the linear motor 30 are not fastened to each other, but in actual operation, the drive shaft 31 and the moving part 24 are They can be fastened together to move. For example, magnets 311 and 241 may be provided at the front end of the driving shaft 31 and the opposite ends of the moving part 24, respectively, and the driving shaft 31 approaches the moving part 24 The two magnets 311 and 241 are attached to each other so that the driving shaft 31 and the moving part 24 may be fastened to each other.

As shown in FIG. 2, the magnet 50 is installed on the moving part 24 so as to move together with the moving part 24 and the piezoelectric element 22. For example, the connection member 23 may be fastened to the lower end of the moving part 24, and the magnet 50 may be installed at the upper end of the moving part 24. Accordingly, the magnet 50 and the piezoelectric element 22 can perform linear reciprocating motion together.

A magnetic sensor 60 is provided that detects the magnetic field of the magnet 50 and outputs a corresponding signal. As shown in FIG. 2, the magnetic sensor 60 may be installed in a fixed position of the housing 21, and may detect a magnetic field generated by the magnet 50 in response to the movement of the magnet 50. So it is installed. For example, if the moving magnet 50 is within the sensing area of the magnetic sensor 60, the magnetic sensor 60 may output an on signal by the magnetic field of the magnet 50, and the magnet 50 When the magnetic sensor 60 is out of the sensing region, the magnetic sensor 60 may output an off signal. That is, since the signal of the magnetic sensor 60 indicates information about the position of the magnet 50, it indicates position information about the position of the piezoelectric element 22 accordingly.

In the high-intensity focused ultrasound apparatus according to an embodiment of the present invention, since it is necessary to cause the piezoelectric element 22 to generate ultrasonic waves in a preset section, the piezoelectric element when the ultrasonic cartridge 20 is newly connected or when the ultrasonic generating operation starts ( It is necessary to detect that 22) is placed in the desired starting position and to start generating ultrasound at that point. In the past, when the magnetic sensor 60 is located at a point where a signal change occurs, it is identified as the starting position of the piezoelectric element and ultrasonic waves are generated. However, in the present invention, as described above, it is recognized that the piezoelectric element may not be in the desired starting position at the time when the signal of the magnetic sensor changes due to the difference in characteristics of the magnet and the magnetic sensor of the individual ultrasonic cartridge and the installation position error, etc. It is to perform position correction control to correct the starting position of the.

A memory 70 for storing the position correction value of the individual cartridge 20 is provided to control the position correction of the piezoelectric element 22, and the controller 40 reads the position correction value stored in the memory 70 and reads the position correction value. The position of the piezoelectric element 22 is corrected based on. The memory 70 may be connected in a wired or wireless manner to communicate with the controller 40 when the ultrasonic cartridge 20 is fastened to the handle 10. Referring to FIG. 4, the memory 70, the magnetic sensor 60, and the magnet 50 may be disposed in the ultrasonic cartridge 20, and when the ultrasonic cartridge 20 is fastened to the handle 10, the memory 170 And the magnetic sensor 60 may be connected to enable data transmission and reception with the controller 40.

The basic concept of the present invention is to manufacture the ultrasonic cartridge 20 so that a magnet and a magnetic sensor having the same magnetic field characteristics and sensing characteristics are placed in a pre-designed position in manufacturing the ultrasonic cartridge 20, which is a consumable that must be replaced when the life span is over. Even so, it has recognized the problem that the position of the magnet at which the magnetic field is detected (or desensed) varies by the magnetic sensor depending on the characteristics of the individual magnets and the magnetic sensor and the error in the installation position during manufacture. In order to correct the error in magnetic field detection, the position correction value is individually measured in advance and stored in the memory of the corresponding ultrasonic cartridge, and when the cartridge is connected to the handle, the position correction value of the piezoelectric element is performed using the position correction value stored in the memory. will be.

The position correction value corresponds to the difference between the measurement position of the piezoelectric element 22 and a predetermined start position of the piezoelectric element 22 measured at the time when the signal of the magnetic sensor 60 changes according to the movement of the magnet 50. It can be calculated as a value. At this time, since the magnet 50 and the piezoelectric element 22 move together with the same displacement, the position of the piezoelectric element 22 can be understood as the position of the magnet 50, and the position of the piezoelectric element 22 Can also be understood as the location of the focal point of the focal ultrasound generated thereby.

5 and 7 illustrate examples for explaining a method of determining a position correction value, and FIGS. 5 and 7 show the same reference start position TP, but the measured measurement start position MP is different from each other. Show That is, in both cases of FIGS. 5 and 7, if the characteristics of the magnet and the magnetic sensor and the installation thereof are ideal, the measurement start position (MP) should match the predesigned reference start position (TP), but the characteristics and installation of the magnet and magnetic sensor The measurement start position MP is different from the reference start position TP due to a position error or the like. In this case, the measurement start position MP may represent a position at which a change in a signal occurs due to the magnetic field detection of the magnetic sensor 60 during the movement of the magnet 50. That is, the moment when the magnet 50 at the initial position in FIGS. 5 and 7 moves to the right and leaves the actual sensing area, or conversely, the moment it moves from the right area of the real sensing area to the left and enters the actual sensing area, the magnetic sensor 60 The signal of is changed from on to off or from off to on. The position at which the change of the detection signal of the magnetic sensor 60 occurs may be regarded as the starting position of the measurement. For each ultrasonic cartridge, a value corresponding to the difference between the predetermined reference start position TP and the measured measurement start position MP may be set as a position correction value. In this case, a section corresponding to a predetermined distance to the right of the preset reference start position TP in FIGS. 5 and 7 corresponds to a preset operation section of the piezoelectric element 22. 5 is a case where the measurement start position MP is located outside the operating section of the piezoelectric element 22 with respect to the reference start position TP, and FIG. 7 shows the measurement start position MP is the reference start position TP This is the case where the piezoelectric element 22 is located within the operating section of the piezoelectric element 22 based on ). At this time, C1 of FIG. 5 and C2 of FIG. 7, which are distances between the reference start position TP and the measurement start position MP, correspond to the position correction values. The position of the piezoelectric element is corrected according to the size and direction (ie, sign) of the position correction value. For example, the controller 40 may determine which of the cases of FIGS. 5 and 7 is based on the sign of the position correction value stored in the memory 70 of the connected ultrasonic cartridge 20.

5 and 6, when the measurement position MP is located outside the operating section of the piezoelectric element 22 with respect to the reference start position TP, the controller 40 is a position correction value C1. The actuator 30 is controlled to continuously move the piezoelectric element 22 forward by a value corresponding to the sum of the preset working distance TL of the piezoelectric element 22 and the piezoelectric element 22. Here, the preset working distance TL corresponds to the distance of the target ultrasonic bath section of the piezoelectric element 22. At this time, the controller 40 allows the piezoelectric element 22 to start generating ultrasonic waves at a point in time when the forward movement of the piezoelectric element 22 is started by the position correction value C1 during the forward movement of the piezoelectric element 22. Can be controlled. As a result, as indicated by the driving step 1 of FIG. 6, the piezoelectric element 22 is continuously moved forward by a value corresponding to the sum of the position correction value and the preset working distance TL of the piezoelectric element. It is possible to pass the section between the start position (TP) and the end position (TP'), and after starting from the measurement position (MP), the piezoelectric element 22 generates ultrasonic waves after moving by the position correction value (C1). By doing so, ultrasonic irradiation can be performed over a desired target ultrasonic irradiation section (a section indicated by a dotted line in the driving step 1). On the other hand, the controller 40 may control the actuator 30 to move backward (drive step 2) in the opposite direction after the piezoelectric element 22 reaches the end position TP'. It may be achieved until the signal of the magnetic sensor 60 is turned on by the magnetic field of 50). The controller 40 may control a cycle consisting of the driving step 1 and the driving step 2 to be repeatedly performed.

On the other hand, referring to FIGS. 7 and 8, when the measurement position MP is located inside the operating section of the piezoelectric element 22 with respect to the reference start position TP, the controller 40 is the piezoelectric element 22 The actuator 30 is controlled so that) moves backward by the position correction value C2 and then moves forward by a preset operating distance TL. That is, the controller 40 moves the piezoelectric element 22 backward by the position correction value C2 as in the driving step 1 of FIG. 8, and then moves the piezoelectric element 22 to a preset operating distance TL as in the driving step 2. ) Move forward. In this case, the controller 40 may control the piezoelectric element 22 to start generating ultrasonic waves at the start of the forward movement of the piezoelectric element. Accordingly, the piezoelectric element 22 can pass a section between the start position (TP) and the end position (TP') of the target ultrasonic irradiation section, and ultrasonic irradiation can be performed in the section (a section indicated by a dotted line in the driving step 2). have. On the other hand, the controller 40 may control the actuator 30 to move backward (drive step 3) in the opposite direction after the piezoelectric element 22 reaches the end position TP'. It may be achieved until the signal of the magnetic sensor 60 is turned on by the magnetic field of 50).

Although the embodiments of the present invention have been described above, the scope of the present invention is not limited thereto, and the embodiments of the present invention are easily changed by those of ordinary skill in the technical field to which the present invention pertains, and are recognized as equivalent. It includes all changes and modifications to the extent that it becomes available.

10: handle
20: ultrasonic cartridge
21: housing
22: piezoelectric element
23: connection member
24: moving part
25: guide rod
30: actuator
31: drive shaft
40: controller
50: magnet
60: magnetic sensor
70: memory

Claims (5)

Actuators that generate driving force,
An ultrasonic cartridge configured to generate ultrasonic waves, and
Controller to control the drive of the actuator
Including,
The ultrasonic cartridge
housing,
A piezoelectric element disposed in the housing and causing ultrasonic vibration by application of power,
A moving part in which the piezoelectric element is mounted and configured to be movable by a driving force of the actuator,
A magnet installed in the moving part to move together with the moving part and the piezoelectric element,
A magnetic sensor that detects a magnetic field generated by the magnet to generate a signal indicating position information on the position of the piezoelectric element, and
A memory for storing a position correction value for correcting the starting position of the piezoelectric element during the ultrasonic generation operation based on the signal from the magnetic sensor
Including,
The controller controls the actuator to correct the starting position of the piezoelectric element based on the signal of the magnetic sensor and the position correction value.
High intensity focused ultrasound device. In claim 1,
The position correction value is measured in advance using the ultrasonic cartridge in which the magnet and the magnetic sensor are installed, and then stored in the memory. In paragraph 2,
The position correction value is calculated as a value corresponding to a difference between a measurement position of the piezoelectric element and a reference start position measured at a time when a signal of the magnetic sensor changes according to the movement of the magnet. In paragraph 3,
When the measurement position is located outside the operation section of the piezoelectric element based on the reference start position, the controller includes the piezoelectric element as much as a value corresponding to the sum of the position correction value and a preset operation distance of the piezoelectric element. High intensity focusing to control the actuator to continuously move forward and to control the piezoelectric element to start generating ultrasonic waves at a point in time when the piezoelectric element is moved forward by the position correction value after starting the forward movement of the piezoelectric element. Ultrasonic device. In paragraph 3,
When the measurement position is located inside the operation section of the piezoelectric element based on the reference start position, the controller moves the piezoelectric element backward by the position correction value and then moves the actuator forward by a preset operation distance. And controlling the piezoelectric element to start generating ultrasonic waves at the start of the forward movement of the piezoelectric element.

Images