JP2018086041A - Liquid injection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress deterioration of visibility of an injection object of a liquid injection device.SOLUTION: A liquid injection device comprises: an injection tube injecting liquid; a liquid chamber communicating with the injection tube; a liquid supply section supplying the liquid to the liquid chamber; a piezoelectric element changing capacity of the liquid chamber; and a piezoelectric element control section applying a periodic pulse voltage to the piezoelectric element, the piezoelectric element control section changing a waveform of the periodic pulse voltage such that the higher a maximum voltage of the periodic pulse voltage is, the lower a frequency of the periodic pulse voltage is.SELECTED DRAWING: Figure 1

Description

  The technology disclosed in this specification relates to liquid ejection.

  As a liquid ejecting apparatus that ejects liquid intermittently, a piezoelectric element is provided, and by applying a periodic pulse voltage to the piezoelectric element, the volume of the liquid chamber containing the liquid is changed, and the liquid is ejected intermittently. A liquid ejecting apparatus is disclosed (for example, see Patent Document 1).

JP 2011-36533 A

  When the liquid ejecting apparatus is used for cutting an object, the larger the liquid ejection amount and the ejection speed of one shot, the higher the cutting energy, and the higher the liquid ejection frequency, the larger the cutting speed (distance that can be cut per unit time). Therefore, when the object to be cut is hard, it is conceivable to increase the maximum drive voltage applied to the piezoelectric element and increase the drive frequency. However, when the maximum value of the drive voltage applied to the piezoelectric element is increased and the drive frequency is increased, there is a problem in that the amount of liquid ejected increases and the visibility of the cutting object deteriorates. In addition, such a subject was a subject common to various uses, such as not only when using a liquid ejecting apparatus for cutting but when using it for washing | cleaning.

  The technology disclosed in the present specification has been made to solve the above-described problems, and can be realized as the following forms.

(1) According to one form of the technique disclosed in this specification, a liquid ejecting apparatus is provided. The liquid ejecting apparatus includes: an ejecting pipe that ejects liquid; a liquid chamber that communicates with the ejecting pipe; a liquid supply unit that supplies the liquid to the liquid chamber; a piezoelectric element that changes the volume of the liquid chamber; A piezoelectric element controller that applies a periodic pulse voltage to the piezoelectric element, wherein the frequency of the periodic pulse voltage is decreased as the maximum voltage of the periodic pulse voltage increases. A piezoelectric element control unit that changes the waveform.

  According to the liquid ejecting apparatus of this aspect, since the frequency is lower as the maximum voltage of the periodic pulse voltage applied to the piezoelectric element is larger, the unit of the liquid ejected intermittently with the application of the periodic pulse voltage An increase in the total amount per hour can be suppressed. Therefore, the deterioration of the visibility of the liquid jet target is suppressed. For example, when the liquid ejecting apparatus is used as a surgical instrument, it is possible to easily secure the surgical field. When cutting or the like using a liquid ejecting apparatus, the maximum amount of the periodic pulse voltage is increased to increase the ejection amount and speed of one ejected liquid (jet). Since kinetic energy can be increased, it is possible to cut a hard cutting object. On the other hand, when the drive frequency is lowered, the liquid ejection interval is increased, but the cutting can be appropriately performed by adjusting the moving speed of the liquid ejection device.

(2) In the liquid ejecting apparatus according to the above aspect, the piezoelectric element control unit is a driving condition of the piezoelectric element including the maximum voltage and the frequency, and is in accordance with one of the plurality of driving conditions. The periodic pulse voltage may be applied, and the driving strip may have the same frequency associated with a plurality of the maximum voltages. If it does in this way, the processing load concerning control of a piezoelectric element can be controlled. In addition, since the same frequency is associated with a plurality of maximum voltages, the frequency of frequency change is reduced compared to the case where different frequencies are associated with a plurality of maximum voltages. Therefore, the user's uncomfortable feeling accompanying the frequency change of the liquid ejecting apparatus can be suppressed.

(3) In the liquid ejecting apparatus of the above aspect, the liquid supply flow rate of the liquid supplied from the liquid supply unit may be constant. If it does in this way, the processing load concerning control of a liquid supply part can be controlled.

  The technology disclosed in this specification can also be realized in various forms other than the liquid ejecting apparatus. For example, a system including a liquid ejecting apparatus, a liquid ejecting method, a method for controlling the liquid ejecting apparatus, a computer program for realizing these methods, a non-transitory storage medium on which the computer program is recorded, and the like It can be realized in various forms.

It is explanatory drawing which shows the whole structure of a liquid ejecting apparatus. It is sectional drawing which cut | disconnected the handpiece along the injection direction of a liquid. It is a functional block diagram of a control device. It is explanatory drawing which shows a drive condition table. It is explanatory drawing which shows the relationship between the maximum voltage defined by a drive condition table, and a drive frequency. An example of the waveform of the drive voltage (piezoelectric element drive signal) applied to a piezoelectric element is shown. It is a flowchart which shows an injection control process.

A. Embodiment:
FIG. 1 is an explanatory diagram illustrating an overall configuration of a liquid ejecting apparatus 1 according to the present embodiment. The liquid ejecting apparatus 1 is used for surgery. Specifically, the liquid ejecting apparatus 1 is an apparatus for executing incision, excision, or crushing (hereinafter collectively referred to as “cutting”) of an affected part as a biological tissue.

  The liquid ejecting apparatus 1 includes a container 10 for storing liquid, a liquid feeding pump 20, a handpiece 30 for ejecting liquid toward a cutting object (in this embodiment, a biological tissue), and a control device 70. Prepare.

  The control device 70 controls the supply of liquid to the handpiece 30 and the ejection of liquid from the handpiece 30. The control device 70 includes an operation panel 80 that is operated by the user at the time of surgery, and a pedal switch 83 for the user to instruct liquid ejection. In FIG. 1, the operation panel 80 is shown in an enlarged manner. The operation panel 80 is provided with a button switch 811 for switching the power ON / OFF, a lever switch 813 for adjusting the amount of liquid to be ejected, the ejection speed, and the ejection cycle, and a monitor 82. . The lever switch 813 is configured to be able to select 10 levels of lever positions with a scale of “1” to “10”. Details of the control device 70 will be described later.

  The container 10 contains a liquid (specifically, physiological saline). The liquid feed pump 20 supplies the liquid contained in the container 10 to the handpiece 30 through the connection tubes 91 and 93 at a constant flow rate.

  The handpiece 30 is a module that the user holds in his / her hand during surgery. The handpiece 30 includes a pulse flow generation unit 40 that generates a pulse flow by applying pulsation to the liquid supplied from the liquid feed pump 20, a pipe-shaped injection pipe 50, and a nozzle 60. The pulse flow generated by the pulse flow generator 40 is ejected from the tip of the nozzle 60 as a pulsed liquid jet (hereinafter abbreviated as a jet).

  The pulse flow means a pulsating flow of liquid in which the flow velocity and pressure of the liquid are large in time and rapidly change. In the present embodiment, the jet is a high-pressure (high energy) liquid (liquid flow) ejected intermittently.

  FIG. 2 is a cross-sectional view of the handpiece 30 cut along the liquid ejecting direction. The vertical and horizontal scales of the members and parts shown in FIG. 2 are not necessarily the same as the actual ones. As shown in FIG. 2, the pulse flow generator 40 varies the volume of the liquid chamber 44 in a cylindrical internal space formed by the first case 41, the second case 42, and the third case 43. Therefore, the piezoelectric element 45 and the diaphragm 46 are arranged. The cases 41, 42, and 43 are joined and integrated on the surfaces facing each other.

  The diaphragm 46 is a disk-shaped thin metal plate, and its outer peripheral portion is sandwiched and fixed between the first case 41 and the second case 42. The piezoelectric element 45 is, for example, a multilayer piezoelectric element, and one end is fixed to the diaphragm 46 and the other end is fixed to the third case 43 between the diaphragm 46 and the third case 43.

  The liquid chamber 44 is a space surrounded by the diaphragm 46 and a recess 411 formed on the surface of the first case 41 facing the diaphragm 46. The liquid chamber 44 communicates with the ejection pipe 50. The first case 41 is formed with an inlet channel 413 and an outlet channel 415 that respectively communicate with the liquid chamber 44. The inner diameter of the outlet channel 415 is formed larger than the inner diameter of the inlet channel 413. The inlet channel 413 is connected to the connection tube 93 and allows the liquid supplied from the liquid feeding pump 20 to flow into the liquid chamber 44. One end of the ejection pipe 50 is connected to the outlet channel 415, and the liquid flowing in the liquid chamber 44 is caused to flow into the ejection pipe 50.

  The nozzle 60 is attached to the other end (tip) of the pipe-like injection tube 50, and has a liquid injection opening 61 having an inner diameter smaller than the inner diameter of the injection tube 50 at the tip.

  The liquid stored in the container 10 (FIG. 1) is supplied to the pulse flow generation unit 40 through the connection tube 93 at a predetermined pressure or a predetermined flow rate by the liquid feeding pump 20 that is operated under the control of the control device 70. . The piezoelectric element 45 expands or contracts in the direction of arrow A in FIG. 2 when a drive signal (periodic pulse voltage) is applied by the control device 70. As a result, pulsation is imparted to the steady flow of liquid flowing in the liquid chamber 44, and the jet is repeatedly ejected from the liquid ejection opening 61. The term “steady flow” as used herein means a flow with small fluctuations in flow velocity and pressure over time. Small time fluctuation means that it is sufficiently small with respect to time fluctuation of flow velocity and pressure in a pulse flow. Time fluctuations in the flow rate and pressure of the steady flow are generated by the rotation of the liquid feed pump 20. The container 10 and the liquid feed pump 20 are collectively referred to as a “liquid supply unit”.

  FIG. 3 is a functional block diagram of the control device 70. The control device 70 includes an operation unit 81, a monitor 82, a control unit 75, and a storage unit 77.

  The operation unit 81 includes the button switch 811, the lever switch 813, and the pedal switch 83 described with reference to FIG. The monitor 82 is realized by a display device such as a liquid crystal display (LCD) or an EL display (electroluminescence display), and various types of setting screens and the like based on a display signal input from the control unit 75. Display the screen.

  The control unit 75 is realized by a microprocessor such as a CPU (Central Processing Unit) or a DSP (Digital Signal Processor), a control device such as an ASIC (Application Specific Integrated Circuit), and an arithmetic device. Control all parts centrally. The control unit 75 includes a piezoelectric element control unit 751, a pump control unit 756, and a display control unit 757.

  The piezoelectric element controller 751 determines the maximum voltage of the periodic pulse voltage as the driving voltage applied to the piezoelectric element 45 (FIG. 2) according to the lever position of the lever switch 813 and the driving frequency that is the frequency. A piezoelectric element drive signal is generated according to the maximum voltage and drive frequency. The piezoelectric element control unit 751 applies the generated piezoelectric element drive signal to the piezoelectric element 45.

  The pump control unit 756 inputs a drive signal to the liquid feeding pump 20 to drive the liquid feeding pump 20. The display control unit 757 causes the monitor 82 to display the output level assigned to the lever position of the lever switch 813.

  The storage unit 77 is realized by various IC (Integrated Circuit) memories such as a ROM (Read Only Memory), a flash ROM, and a RAM (Random Access Memory), and a storage medium such as a hard disk. The storage unit 77 stores a drive condition table 771 (described later) and a program (not shown) for realizing various functions provided in the liquid ejecting apparatus 1. Further, the storage unit 77 stores data used during execution of the program in advance, or temporarily stores it every time processing is performed.

  FIG. 4A is an explanatory diagram showing the drive condition table 771. The drive condition table 771 includes a plurality of drive conditions (including the maximum voltage Vm and the drive frequency f) for the piezoelectric element 45. As driving conditions, the maximum voltage Vm (V) of the driving voltage of the piezoelectric element 45, the driving frequency f (Hz), and the liquid supply flow rate Q (ml / min) are associated with the output level. Here, the output level is determined by operating the lever switch 813 (FIG. 1). Note that the output level 0 is not set by operating the lever switch 813, but is set when the pedal switch 83 is not depressed in order to prevent liquid from being ejected. The liquid supply flow rate Q is the volume of liquid that the liquid feed pump 20 supplies to the handpiece 30 per unit time.

  FIG. 4B is an explanatory diagram showing the relationship between the maximum voltage Vm and the drive frequency f determined by the drive condition table 771. In the present embodiment, the lower drive frequency f is set as the maximum voltage Vm of the drive voltage of the piezoelectric element 45 is larger. Specifically, when the maximum voltage Vm is 5, 10, 15 (V), the driving frequency f is 500 (Hz), and when the maximum voltage Vm is 20, 25, 30 (V), the driving frequency f is 400 (Hz). Hz), the driving frequency f when the maximum voltage Vm is 35, 40, 45 (V) is 300 (Hz), and the driving frequency f when the maximum voltage Vm is 50 (V) is 200 (Hz). It is. That is, in the drive condition table 771, the same drive frequency f is associated with a plurality of maximum voltages Vm.

  FIG. 5 shows an example of the waveform of the drive voltage (piezoelectric element drive signal) applied to the piezoelectric element 45. In FIG. 5, the horizontal axis indicates time, and the vertical axis indicates drive voltage. The drive voltage waveform L3 at the output level 3 determined by the drive condition table 771 shown in FIG. 4A is indicated by a solid line, and the drive voltage waveform L4 at the output level 4 is indicated by a broken line. In one cycle (T0) of the drive voltage waveform L3, no voltage is applied during the rising period (a) when the voltage increases, the time (b) when the voltage becomes maximum, and the falling period (c) when the voltage decreases. And a rest period (d). The reciprocal of the period T0 is the frequency of the drive signal (drive frequency).

  The waveform of the rising period (a) of the drive voltage is a waveform corresponding to ½ period of the sin waveform offset in the positive voltage direction and shifted in phase by −90 degrees. The waveform of the falling period (c) of the drive voltage is a waveform corresponding to ½ period of the sin waveform offset in the positive voltage direction and shifted in phase by +90 degrees. The period of the sin waveform in the falling period (c) is larger than the period of the sin waveform in the rising period.

  The drive voltage waveform L4 has a maximum voltage Vm different from the drive voltage waveform L3 (greater than the drive voltage waveform L3), but the drive voltage rise period (a), the time when the voltage becomes maximum (b), and the drive voltage fall The period (c) is the same as the drive voltage waveform L3 and has a similar sin waveform. In the drive voltage waveform L4, the pause period (d1) is set longer than the drive voltage waveform L3, and the drive frequency is smaller than the drive voltage waveform L3.

  As shown in FIG. 5, when a periodic pulse voltage is applied as the drive voltage of the piezoelectric element 45, a jet (liquid) is periodically ejected. The period in which the jet is ejected coincides with the period of the driving voltage. Thus, intermittent (periodic) jetting of the jet is brought about by driving the piezoelectric element 45. Driving the piezoelectric element 45 means that the piezoelectric element 45 periodically expands and contracts.

  Since the piezoelectric element 45 in this embodiment expands when a positive voltage is applied, the piezoelectric element 45 rapidly expands in the rising period (a), and the diaphragm 46 is pushed by the piezoelectric element 45 and bends toward the liquid chamber 44 ( (Left side in FIG. 2). When the diaphragm 46 is bent toward the liquid chamber 44, the volume of the liquid chamber 44 is reduced, and the liquid in the liquid chamber 44 is pushed out of the liquid chamber 44. Since the inner diameter of the outlet channel 415 is larger than the inner diameter of the inlet channel 413, the fluid inertance and fluid resistance of the outlet channel 415 are smaller than the value of the inlet channel 413. Therefore, most of the liquid pushed out of the liquid chamber 44 by the rapid expansion of the piezoelectric element 45 flows into the ejection pipe 50 through the outlet channel 415 as a pulse flow, and the liquid ejection opening having a smaller diameter than the inner diameter. From the part 61, it is injected as a jet. The jet is a dominant factor that determines the fracture state of the cutting object, that is, the cutting depth of the cutting object.

  The drive voltage gradually falls after rising to the maximum voltage (falling period (c)). Therefore, the piezoelectric element 45 contracts over a longer time than the rising period (a), and the diaphragm 46 is pulled by the piezoelectric element 45 and bent toward the third case 43 side. When the diaphragm 46 bends toward the third case 43 side, the volume of the liquid chamber 44 increases, and the liquid flows into the liquid chamber 44 from the inlet channel 413.

  Since the liquid feed pump 20 supplies the liquid to the pulse flow generation unit 40 at a constant liquid supply flow rate Q, if the piezoelectric element 45 does not expand and contract, the liquid flowing in the liquid chamber 44 exits as a steady flow. It flows into the ejection pipe 50 through the flow path 415 and is ejected from the liquid ejection opening 61.

  FIG. 6 is a flowchart showing the injection control process. The injection control process is executed by the control unit 75. The control unit 75 starts the injection control process when the pedal switch 83 is turned on.

  In step S211, the piezoelectric element control unit 751 acquires the lever position of the lever switch 813, reads the maximum voltage Vm and the driving frequency f corresponding to the acquired lever position (output level) from the driving condition table 771, A maximum voltage Vm and a driving frequency f of the driving voltage applied to the piezoelectric element are determined.

  In step S212, the piezoelectric element control unit 751 generates a piezoelectric element drive signal having a drive voltage waveform using the maximum voltage Vm and the drive frequency f determined in step S211, and applies (outputs) the piezoelectric element drive signal to the piezoelectric element. The control unit 756 outputs a drive signal for driving the liquid feeding pump 20. As shown in FIG. 4A, the liquid supply flow rate is constant regardless of the maximum voltage Vm and the driving frequency f.

  In step S213, the display control unit causes the monitor 82 to display the output level assigned to the acquired lever position.

  Thereafter, the control unit 75 waits for an input operation while continuing to output the drive signal (step S215). When the lever switch 813 has been operated (step S215, lever switch), the control unit 75 returns to the process of step S211. That is, the maximum voltage Vm and the drive frequency f are determined according to the changed output level (step S211), and the drive signal output (step S212) and the output level display (step S213) are executed.

  On the other hand, when it is operated that the pedal switch is OFF (step S215, pedal switch OFF), the control unit 75 ends the injection control process.

  As described above, according to the liquid ejecting apparatus 1 of the present embodiment, the piezoelectric element drive signal is generated so that the drive frequency f decreases as the maximum voltage Vm of the drive voltage applied to the piezoelectric element 45 increases. ing. For example, when a human brain surgery is performed using the liquid ejecting apparatus 1, depending on the type of tumor in the brain, the tumor part is harder than a normal part other than the tumor, and thus the liquid ejecting apparatus 1 ejects the tumor. We want to increase the kinetic energy of the jetted liquid (jet) by increasing the flow rate and amount of the jetted liquid (jet), and perform tumor cutting in the brain. At this time, it is conceivable that the maximum voltage Vm of the drive voltage applied to the piezoelectric element 45 is increased and the drive frequency f is increased. In this way, the energy of the jet can be increased to increase the cutting force, and the cutting speed (distance that can be cut per unit time) can be increased. However, if the maximum voltage Vm and the drive frequency f are both increased, there is a possibility that the liquid supply by the liquid feed pump 20 may not be in time. In the operation, the liquid ejecting apparatus 1 ejects the liquid and sucks the ejected liquid to secure the surgical field. However, when the driving frequency f is high, the jet ejection frequency is high. Therefore, the suction cannot catch up, and it may be difficult to secure the operative field. In contrast, in the liquid ejecting apparatus 1 of the present embodiment, the larger the maximum voltage Vm of the driving voltage applied to the piezoelectric element 45 is, the lower the driving frequency f is, so the number of jets ejected per unit time is the maximum. Since the drive frequency f increases as the voltage Vm increases, it is easy to secure a surgical field by suction of the ejected liquid. Note that when the drive frequency f is lowered, the liquid ejection interval is increased, but the cutting can be appropriately performed by adjusting the moving speed of the liquid ejection apparatus 1.

  Further, in the liquid ejecting apparatus 1 of the present embodiment, the liquid supply flow rate supplied from the liquid feed pump 20 is made constant regardless of changes in the maximum voltage Vm of the drive voltage of the piezoelectric element 45 and the drive frequency f. Therefore, the control of the liquid feed pump 20 is easy, and the processing load related to the control of the liquid feed pump 20 can be suppressed.

  Further, when a tube pump is used as the liquid feed pump 20, the liquid supplied to the liquid chamber 44 has a small variation in flow rate and pressure with time. When the liquid supply flow rate from the liquid feed pump 20 is changed, the time fluctuation of the flow velocity and pressure changes, so that there is a possibility that the cycle of liquid pulsation generated by driving the piezoelectric element 45 may be affected. On the other hand, when the liquid supply flow rate is constant, the pulsation cycle can be appropriately controlled.

  Further, although the liquid supply flow rate is constant, the drive frequency f is lowered as the maximum voltage Vm of the drive voltage of the piezoelectric element 45 is increased, thereby reducing the possibility that the liquid supply amount of the liquid feed pump 20 is insufficient. can do. Moreover, since the liquid supply flow rate is kept constant, the deterioration of the surgical field can be suppressed.

B. Variations:
(1) The liquid ejecting apparatus is not limited to the type using the piezoelectric element exemplified in the embodiment.
For example, a liquid ejecting apparatus of a type that intermittently ejects liquid by evaporating the liquid in the liquid chamber by irradiating the liquid chamber with a pulse laser may be used. As the laser source, for example, a holmium Yag laser (Ho: YAG laser) or the like can be employed.

  Alternatively, a valve-type liquid ejecting apparatus may be used. The valve type is a method of controlling the injection by closing the valve when not injecting liquid and opening the valve when injecting liquid. The valve is provided between the liquid chamber and the nozzle. When the valve is closed, the flow of liquid from the liquid chamber to the nozzle is blocked. The liquid in the liquid chamber is pressurized regardless of whether the valve is opened or closed. Therefore, when the valve is opened, liquid is ejected from the nozzle. In this way, the liquid can be ejected intermittently.

  In the case of the example using the pulse laser and the valve type example, control is performed such that the higher the energy of the jet jet, the lower the jetting frequency. If it does in this way, the deterioration of the visibility of the target of liquid injection will be controlled.

(2) The setting of the output level is not limited to the above embodiment. For example, in the range where the maximum voltage Vm is 5 to 30 (V), the drive frequency f may be 400 (Hz), and in the range where the maximum voltage Vm is 35 to 500 (V), the drive frequency f may be 200 (Hz). Further, the output level may be set to any number as long as it is two or more. The intervals of the maximum voltage Vm at the output level need not be set at equal intervals.

  In the above embodiment, an example is shown in which the drive frequency f is set to be stepwise lower with respect to the maximum voltage Vm. However, the drive frequency f is set to be linearly lower with respect to the maximum voltage Vm. Also good. Further, the drive frequency f may be determined so that the liquid ejection amount per unit time is constant with respect to the maximum voltage Vm. However, since the drive frequency f affects the cutting speed (distance that can be cut per unit time), if the drive frequency f differs for each maximum voltage Vm (for each output level), the user is changed each time the output level is changed. Since the speed at which the hand is moved is changed, it can be said that a user with less change in driving frequency is easier to use.

(3) In the above embodiment, the control device 70 includes the drive condition table 771, and the piezoelectric element control unit 751 refers to the drive condition table 771 to determine one drive condition (maximum voltage Vm, drive frequency f). Although the example to do was shown, it is not limited to the said embodiment. For example, the relationship between the maximum voltage Vm and the drive frequency f may be determined in advance using a mathematical expression, and the drive frequency f corresponding to the maximum voltage Vm determined by the user may be calculated using the mathematical expression.

(4) In the above embodiment, the example in which the liquid supply flow rate by the liquid feeding pump 20 is made constant regardless of the maximum voltage and the drive frequency has been shown. However, the liquid supply flow rate is changed according to the maximum voltage and the drive frequency. May be. However, it is preferable to make the liquid supply flow rate constant because the liquid feed pump 20 can be easily controlled.

(5) In the above-described embodiment, the example in which the liquid ejecting apparatus 1 is used as a surgical instrument has been described. In addition, the target for ejecting the liquid may be a flexible material other than a living tissue, for example, a food material, a gel material, a resin material such as rubber or plastic.

(6) In the above embodiment, the sin waveform is exemplified as the waveform of the drive voltage applied to the piezoelectric element 45. However, for example, a rectangular pulse wave may be used. Further, as an example of changing the drive frequency f, an example in which the pause period is changed has been shown, but at least one of the rising period (a) and the falling period (c) may be changed.

(7) In the above embodiment, some or all of the functions and processes realized by software may be realized by hardware. In addition, some or all of the functions and processes realized by hardware may be realized by software. As the hardware, for example, various circuits such as an integrated circuit, a discrete circuit, or a circuit module obtained by combining these circuits can be used.

  The technology disclosed in the present specification is not limited to the embodiments and modifications of the present specification, and can be realized with various configurations without departing from the spirit of the technology. For example, the technical features in the embodiments and the modifications corresponding to the technical features in each embodiment described in the summary section of the invention may be used to solve part or all of the above-described problems, or In order to achieve part or all of the effects, replacements or combinations can be made as appropriate. If the technical feature is not described as essential in this specification, it can be deleted as appropriate.

  DESCRIPTION OF SYMBOLS 1 ... Liquid injection apparatus, 10 ... Container, 20 ... Liquid feed pump, 30 ... Handpiece, 40 ... Pulse flow generation part, 41 ... 1st case, 42 ... 2nd case, 43 ... 3rd case, 44 ... Liquid chamber , 45 ... Piezoelectric element, 46 ... Diaphragm, 50 ... Injection pipe, 60 ... Nozzle, 61 ... Liquid injection opening, 70 ... Control device, 75 ... Control part, 77 ... Storage part, 80 ... Operation panel, 81 ... Operation part , 82 ... Monitor, 83 ... Pedal switch, 91 ... Connection tube, 93 ... Connection tube, 411 ... Recess, 413 ... Inlet channel, 415 ... Outlet channel, 751 ... Piezoelectric element control unit, 756 ... Pump control unit, 757 ... Display control unit, 771 ... Drive condition table, 811 ... Button switch, 813 ... Lever switch, Vm ... Maximum voltage, f ... Drive frequency

Claims (3)

An injection tube for injecting liquid;
A liquid chamber in communication with the jet pipe;
A liquid supply section for supplying the liquid to the liquid chamber;
A piezoelectric element for changing the volume of the liquid chamber;
A piezoelectric element controller that applies a periodic pulse voltage to the piezoelectric element, wherein the frequency of the periodic pulse voltage is decreased as the maximum voltage of the periodic pulse voltage increases. A piezoelectric element controller for changing the waveform;
A liquid ejecting apparatus comprising: The liquid ejecting apparatus according to claim 1,
The piezoelectric element controller is
A driving condition of the piezoelectric element including the maximum voltage and the frequency, wherein the periodic pulse voltage is applied according to the driving condition of one of a plurality of the driving conditions,
In the liquid ejecting apparatus, the driving strip is associated with the same frequency with respect to a plurality of the maximum voltages. The liquid ejecting apparatus according to claim 1 or 2,
The liquid ejecting apparatus, wherein a liquid supply flow rate of the liquid supplied from the liquid supply unit is constant.

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