JP2010051517A - Fluid injection device, fluid injection surgical implement, and fluid injection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid injection device for injecting a pulse flow with a characteristic suitable for the property of an object to which the pulse flow is injected, and to provide a fluid injection surgical implement, and a fluid injection method. <P>SOLUTION: The fluid injection device 1 includes: a pulse generating part 100 having a fluid chamber 501 and a capacity changing means 401 for changing the capacity of the fluid chamber 501; a flow passage tube 200 having a connection flow passage 201 communicating with the fluid chamber 501 and 212; a fluid supply means 20 for supplying a fluid to the fluid chamber 501; a control means 30 for controlling the change of the capacity of the fluid chamber 501 by the capacity changing means 401; and a hardness detecting means 40 for detecting the hardness of the fluid injection object to which the fluid is injected. The control means 30 controls the change of the capacity of the fluid chamber 501 by the capacity changing means 401 in response to the hardness detected by the hardness detecting means 40. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fluid ejecting apparatus that ejects pressurized fluid, a fluid ejecting surgical instrument, and a fluid ejecting method.

Conventionally, as this type of technology, for example, a pulsation generator having a flow path tube having a connection flow path communicating with a fluid ejection port, a fluid chamber communicating with the connection flow path, and a piezoelectric element that changes the volume of the fluid chamber And a fluid ejecting device that supplies fluid to the fluid chamber (see Patent Document 1).
In this fluid ejecting apparatus, the fluid supply means supplies fluid to the fluid chamber, and the piezoelectric element changes the volume of the fluid chamber, thereby ejecting pulsating fluid (hereinafter referred to as pulsating flow) from the fluid ejection port. It becomes possible.
JP 2008-82202 A

However, in the above-described prior art, it may be difficult to inject a pulsating flow having characteristics suitable for the properties of an object that injects the pulsating flow.
For example, when the fluid ejecting apparatus is applied to a fluid ejecting instrument that excises a site to be excised, it is necessary to change the characteristics of the ejected pulsating flow according to the nature of the site to be excised. However, the prior art does not have a function of changing the characteristics of the pulsating flow.
The present invention has been made in view of the above prior art, and is a fluid ejecting apparatus, a fluid ejecting surgical instrument, and a fluid capable of ejecting a pulsating flow having characteristics suitable for the properties of an object that ejects the pulsating flow It is an object to provide an injection method.

  In order to achieve the above object, a fluid ejecting apparatus according to a first aspect of the present invention includes a pulsation generating unit having a fluid chamber into which a fluid flows and a volume changing means for changing the volume of the fluid chamber, a fluid chamber and a fluid ejection port A flow path pipe having a connecting flow path communicating therewith, a fluid supply means for supplying a fluid to the fluid chamber, a control means for controlling the change of the volume of the fluid chamber by the volume changing means, and a fluid ejection target for ejecting the fluid Hardness detecting means for detecting hardness, and the control means controls the change of the volume of the fluid chamber by the volume changing means according to the hardness detected by the hardness detecting means.

In the fluid ejecting apparatus according to the first aspect of the invention, in order to control the change of the volume of the fluid chamber by the volume changing means according to the hardness of the fluid ejecting object, a pulsating flow having characteristics suitable for the properties of the fluid ejecting object is provided. It becomes possible to inject.
Here, for example, a fluid chamber 501 described later corresponds to the fluid chamber. For example, a piezoelectric element 401 described later corresponds to the volume changing unit. For example, an inlet channel 503 described later corresponds to the inlet channel. For example, an outlet channel 511 described later corresponds to the outlet channel. As the pulsation generation unit, for example, a pulsation generation unit 100 described later corresponds. For example, a connection channel 201 described later corresponds to the connection channel. For example, a fluid ejection opening 212 described later corresponds to the fluid ejection port. An example of the flow path tube is a connection flow path tube 200 described later. For example, a pump 20 described later corresponds to the fluid supply unit. For example, the control means 30 described later corresponds to the control means. As the hardness detection means, for example, hardness detection means 40 described later corresponds.

Moreover, the fluid ejection device according to the second invention is the fluid ejection device according to the first invention, wherein the hardness detection means has a resonance frequency detection means for detecting a resonance frequency of the fluid ejection object, and the resonance frequency Based on the resonance frequency detected by the detecting means, the hardness of the fluid ejecting object that ejects the fluid is detected.
In the fluid ejecting apparatus according to the second aspect of the invention, the hardness is detected based on the resonance frequency of the fluid ejecting object, so that the hardness of the fluid ejecting object can be easily detected.
Here, as the resonance frequency detection means, for example, a vibration detection unit 42 and a resonance frequency detection unit 43, which will be described later, correspond.

The fluid ejecting apparatus according to the third invention is the fluid ejecting apparatus according to the first or second invention, wherein the volume changing means is a piezoelectric element, and the control means has a hardness detected by the hardness detecting means. Accordingly, the voltage applied to the piezoelectric element is controlled.
In the fluid ejecting apparatus according to the third aspect of the invention, the voltage applied to the piezoelectric element is controlled according to the hardness of the fluid ejecting object, so that the pressure of the fluid ejected from the channel tube can be adjusted with a simple configuration. It becomes.
Here, for example, a piezoelectric element 401 described later corresponds to the piezoelectric element.

The fluid ejecting apparatus according to the fourth invention is the fluid ejecting apparatus according to any one of the first to third inventions, wherein the control means is configured such that the harder the hardness detected by the hardness detecting means, The change of the volume of the fluid chamber by the volume changing means is controlled so that the pressure of the fluid jetted from the jet port becomes high.
In the fluid ejecting apparatus according to the fourth aspect of the present invention, it is possible to more appropriately adjust the pressure of the fluid ejected from the flow channel pipe according to the hardness of the fluid ejecting object.

A fluid ejection surgical instrument according to a fifth aspect of the present invention includes a fluid flow chamber into which a fluid flows and a pulsation generator having a volume changing means for changing the volume of the fluid chamber, and a connection flow path communicating with the fluid chamber and the fluid ejection port. A fluid supply means for supplying a fluid to the fluid chamber, a control means for controlling the change of the volume of the fluid chamber by the volume changing means, and a hardness for detecting the hardness of the surgical target site for ejecting the fluid Detecting means, and the control means controls the change of the volume of the fluid chamber by the volume changing means according to the hardness detected by the hardness detecting means, and the volume changing means changes the volume of the fluid chamber. Thus, the surgical target site is incised or excised with the fluid ejected from the fluid ejection port.
In the fluid ejection surgical instrument according to the fifth invention, in order to control the change of the volume of the fluid chamber by the volume changing means according to the hardness of the surgical target part, a pulsating flow having characteristics suitable for the characteristics of the surgical target part is jetted. It becomes possible to do.

In the fluid ejection method according to the sixth aspect of the present invention, the fluid is supplied from the fluid ejection port communicating with the connection flow path by supplying fluid to the fluid chamber communicating with the connection flow path and changing the volume of the fluid chamber. The fluid is ejected, the hardness of the fluid ejection object that ejects the fluid is detected, and the change in the volume of the fluid chamber is controlled according to the detected hardness.
In the fluid ejecting method according to the sixth aspect of the invention, since the change of the volume of the fluid chamber by the volume changing means is controlled according to the hardness of the fluid ejecting object, a pulsating flow having characteristics suitable for the properties of the fluid ejecting object is provided. It becomes possible to inject.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The fluid ejecting apparatus according to the present invention can be applied to drawing using ink or the like, washing of fine objects and structures, a scalpel for surgery, and the like.
In the present embodiment, a case will be described in which the fluid ejection device according to the present invention is applied to a water pulse knife suitable for incising or excising a living tissue at a site to be operated. Therefore, the fluid used in the present embodiment is water, physiological saline, a chemical solution, or the like.

(Constitution)
FIG. 1 is a schematic configuration diagram showing a water pulse knife according to an embodiment of the present invention.
A water pulse knife (fluid ejecting apparatus, fluid ejecting surgical instrument) 1 shown in FIG. 1 pulsates a fluid container 10 that contains fluid, a pump 20 that supplies fluid at a constant pressure, and fluid supplied from the pump 20. A pulsation generation unit 100 that flows, a control unit 30 that controls the pulsation generation unit 100 and the pump 20, and a hardness detection unit 40 are provided.
The fluid container 10 contains a fluid such as water, physiological saline, or a chemical solution.
The pump 20 sucks the fluid stored in the fluid container 10 through the connection tube 15. The pump 20 supplies the sucked fluid to the pulsation generator 100 through the connection tube 25 at a constant pressure. The discharge pressure of the pump 20 is generally set to 3 atm (0.3 MPa) or less.

Note that when performing an operation using the water pulse knife 1, the part grasped by the operator is the pulsation generator 100. Therefore, it is preferable that the connection tube 25 up to the pulsation generator 100 be as flexible as possible. For this purpose, it is preferable that the pressure is reduced within a range in which fluid can be sent to the pulsation generator 100 with a flexible and thin tube.
The pulsation generator 100 includes a fluid chamber 501 (see FIG. 2) and a volume changing unit for the fluid chamber 501. In the present embodiment, the piezoelectric element 401 is used as the volume changing means of the fluid chamber 501.

Next, the pulsation generator 100 will be described in more detail with reference to the drawings.
FIG. 2 is a cross-sectional view showing a pulsation generating portion of the water pulse knife shown in FIG. 2 is a cross-sectional view taken along line AA ′ shown in FIG. FIG. 3 is a perspective view schematically showing a state in which the pulsation generator shown in FIG. 2 is disassembled.
As shown in FIGS. 2 and 3, the pulsation generator 100 includes an upper case 500 and a lower case 301. Then, the upper case 500 and the lower case 301 are joined on the surfaces facing each other, and are screwed together by four fixing screws (not shown).
The lower case 301 is a cylindrical member having a flange, and one end is sealed with a bottom plate 311. A piezoelectric element 401 is disposed in the internal space of the lower case 301.

The piezoelectric element 401 is a laminated piezoelectric element and constitutes an actuator. One end of the piezoelectric element 401 is fixed to the diaphragm 400 via the upper plate 411. The other end of the piezoelectric element 401 is fixed to the upper surface 312 of the bottom plate 311.
Diaphragm 400 is formed of a disk-shaped metal thin plate, and a peripheral edge thereof is closely fixed to a bottom surface of recess 303 in recess 303 of lower case 301. By inputting a drive signal to the piezoelectric element 401 as volume changing means, the volume of the fluid chamber 501 is changed via the diaphragm 400 as the piezoelectric element 401 expands and contracts. Thus, by adopting a structure that employs the piezoelectric element 401 and the diaphragm 400 as the volume changing means, the structure can be simplified and the size can be reduced accordingly. Moreover, the maximum frequency of the volume change of the fluid chamber 501 can be set to a high frequency of 1 KHz or more, which is optimal for high-speed pulsating flow injection.

On the upper surface of the diaphragm 400, a reinforcing plate 410 (not shown in FIG. 3) made of a disk-shaped thin metal plate having an opening at the center is laminated.
The upper case 500 has a recess at the center of the surface facing the lower case 301. A fluid chamber 501 is a rotating body formed of the recess and the diaphragm 400 and filled with fluid. That is, the fluid chamber 501 is a space surrounded by the sealing surface 505 of the concave portion of the upper case 500, the inner peripheral side wall 501 a, and the diaphragm 400. An outlet channel 511 is formed in a substantially central portion of the fluid chamber 501.
The outlet channel 511 is penetrated from the fluid chamber 501 to the end of the outlet channel pipe 510 protruding from one end surface of the upper case 500. A connection portion between the outlet channel 511 and the sealing surface 505 of the fluid chamber 501 is smoothly rounded to reduce fluid resistance.

In addition, although the shape of the fluid chamber 501 is a substantially cylindrical shape with both ends sealed in this embodiment (see FIG. 2), it may be conical, trapezoidal, hemispherical, or the like when viewed from the side. For example, if the connecting portion between the outlet channel 511 and the sealing surface 505 is shaped like a funnel, bubbles in the fluid chamber 501 described later can be easily discharged.
A connection channel pipe 200 is connected to the outlet channel pipe 510. A connection channel 201 is formed in the connection channel pipe 200. The diameter of the connection channel 201 is formed larger than the diameter of the outlet channel 511. Further, the thickness of the pipe portion of the connection flow path pipe 200 is formed in a range having rigidity that does not absorb the pressure pulsation of the fluid.

A nozzle 211 is inserted into the distal end portion of the connection flow channel pipe 200. A fluid ejection port 212 is formed in the nozzle 211. The diameter of the fluid ejection port 212 is smaller than the diameter of the connection channel 201.
On the side surface of the upper case 500, an inlet channel tube 502 into which the connection tube 25 that supplies fluid from the pump 20 is inserted is projected. A connection channel 504 on the inlet channel side is formed in the inlet channel tube 502. The connection channel 504 communicates with the inlet channel 503. The inlet channel 503 is formed in a groove shape on the peripheral edge of the sealing surface 505 of the fluid chamber 501 and communicates with the fluid chamber 501.

A packing box 304 is formed on the lower case 301 side and a packing box 506 is formed on the upper case 500 side at a position spaced apart in the outer peripheral direction of the diaphragm 400 on the joint surface between the upper case 500 and the lower case 301. A ring-shaped packing 450 is mounted in a space formed by the packing box 304 and the packing box 506.
Here, when the upper case 500 and the lower case 301 are assembled, the peripheral portion of the diaphragm 400 and the peripheral portion of the reinforcing plate 410 are the peripheral portion of the sealing surface 505 of the upper case 500 and the concave portion 303 of the lower case 301. It is closely attached by the bottom. At this time, the packing 450 is pressed by the upper case 500 and the lower case 301 to prevent fluid leakage from the fluid chamber 501.

The fluid chamber 501 is in a high pressure state of 30 atm (3 MPa) or more when fluid is discharged, and the fluid may slightly leak at the joints of the diaphragm 400, the reinforcing plate 410, the upper case 500, and the lower case 301. However, the packing 450 prevents leakage.
When the packing 450 is disposed as shown in FIG. 2, the packing 450 is compressed by the pressure of the fluid leaking from the fluid chamber 501 at a high pressure, and is further pressed against the walls in the packing boxes 304 and 506. Leakage can be more reliably prevented. From this, a high pressure rise in the fluid chamber 501 can be maintained during driving.

Next, the inlet channel 503 formed in the upper case 500 will be described in more detail with reference to the drawings.
FIG. 4 is a plan view showing the inlet flow path of the pulsation generating section shown in FIG. 2, and shows a state in which the upper case is viewed from the joint surface side with the lower case.
As shown in FIG. 4, the inlet channel 503 has one end communicating with the fluid chamber 501 and the other end communicating with the connection channel 504. A fluid reservoir 507 is formed at a connection portion between the inlet channel 503 and the connection channel 504. By providing the fluid reservoir 507 at the connection portion between the inlet channel 503 and the connection channel 504, the influence of the inertance of the connection channel 504 on the inlet channel 503 can be suppressed. The connection between the fluid reservoir 507 and the inlet channel 503 is smoothly rounded to reduce the fluid resistance.

In addition, the inlet channel 503 communicates with the inner peripheral side wall 501a of the fluid chamber 501 in a substantially tangential direction. The fluid supplied at a constant pressure from the pump 20 (see FIG. 1) flows along the inner peripheral wall 501a (in the direction indicated by the arrow in FIG. 4) to generate a swirling flow in the fluid chamber 501. The swirling flow is pressed against the inner peripheral side wall 501a by the centrifugal force caused by swirling, and the bubbles contained in the fluid chamber 501 are concentrated at the center of the swirling flow.
Then, the bubbles collected at the center are excluded from the outlet channel 511. For this reason, it is more preferable that the outlet channel 511 is provided in the vicinity of the center of the swirling flow, that is, in the axial center portion of the rotating body. In FIG. 4, the planar shape of the inlet channel 503 is curved. The inlet channel 503 may be communicated with the fluid chamber 501 in a straight line, but is curved from the necessity of increasing the channel length of the inlet channel 503 in order to obtain a desired inertance in a narrow space. .

  In addition, as shown in FIG. 2, the reinforcement board 410 is arrange | positioned between the diaphragm 400 and the peripheral part of the sealing surface 505 in which the inlet flow path 503 is formed. The meaning of providing the reinforcing plate 410 is to improve the durability of the diaphragm 400. Since the notch-like connection opening 509 is formed in the connection portion of the inlet channel 503 with the fluid chamber 501, stress concentration occurs in the vicinity of the connection opening 509 when the diaphragm 400 is driven at a high frequency. May cause fatigue failure. Therefore, by providing the reinforcing plate 410 having a continuous opening without a notch, stress concentration does not occur in the diaphragm 400.

Further, four screw holes 500a are formed at the outer peripheral corner of the upper case 500, and the upper case 500 and the lower case 301 are screwed and joined at the screw hole positions.
Although illustration is omitted, the reinforcing plate 410 and the diaphragm 400 can be joined and integrally laminated and fixed. If the reinforcing plate 410 and the diaphragm 400 are laminated and fixed together, the assembling property of the pulsation generating unit 100 can be improved, and the outer peripheral edge of the diaphragm 400 can be reinforced. As an adhering means, solid layer diffusion bonding, welding, or the like can be adopted even when sticking using an adhesive, but the reinforcing plate 410 and the diaphragm 400 are more closely attached to each other at the joining surface. preferable.

FIG. 5 is a schematic configuration diagram of hardness detection means and control means.
The hardness detection means 40 detects the hardness of the surgical target site (fluid ejection target). As shown in FIG. 5, the hardness detection unit 40 includes a detection start instruction unit 41, a vibration detection unit 42, a resonance frequency detection unit 43, and a hardness calculation unit 44.
The detection start instruction unit 41 inputs a hardness detection start signal to a voltage control unit 32 (to be described later) of the control unit 30 when a hardness detection mode changeover switch (not shown) is operated to an ON state.
The vibration detection unit 42 detects the vibration of the surgical target part by contacting the surgical target part. Then, the vibration detection unit 42 inputs the detected vibration of the surgical target site to the resonance frequency detection unit 43.

The resonance frequency detection unit 43 detects the resonance frequency of the surgical target site based on the vibration of the surgical target site input from the vibration detection unit 42. Then, the resonance frequency detection unit 43 inputs the detected resonance frequency to the hardness calculation unit 44.
The hardness calculation unit 44 calculates the hardness of the surgical target site based on the resonance frequency input from the resonance frequency detection unit 43. Then, the hardness calculation unit 44 inputs the calculated hardness of the surgical target site to the voltage control unit 32 of the control unit 30. Specifically, based on the resonance frequency input from the resonance frequency detection unit 43, the hardness is calculated by a predetermined arithmetic expression indicating the relationship between the resonance frequency and the hardness. Further, based on the resonance frequency input from the resonance frequency detection unit 43, the hardness may be calculated by a predetermined table indicating the relationship between the resonance frequency and the hardness.

As shown in FIG. 5, the control unit 30 includes a pump control unit 31 that controls the pump 20 and a voltage control unit 32 that controls the piezoelectric element 401 of the pulsation generating unit 100.
The pump control unit 31 controls the pressure of the fluid that the pump 20 supplies to the pulsation generating unit 100.
The voltage control unit 32 controls the voltage applied to the piezoelectric element 401 of the pulsation generating unit 100.
Specifically, the voltage control unit 32 generates a predetermined sampling pulsating flow when a hardness detection start signal is input from the detection start instruction unit 41 of the hardness detection unit 40 (when the hardness detection mode is set). A sampling voltage signal (driving signal) is input to the piezoelectric element 401 of the pulsation generator 100 so as to inject. Here, the predetermined sampling pulsating flow refers to a pulsating flow that is injected by changing the frequency continuously within a predetermined range.

  In addition, the voltage control unit 32 applies a voltage to the piezoelectric element 401 of the pulsation generating unit 100 according to the hardness of the surgical target site input from the hardness calculation unit 44 of the hardness detection unit 40 in the normal injection mode. To control. In this case, the voltage control unit 32 applies the piezoelectric element 401 so that the pressure of the fluid ejected from the fluid ejection opening 212 increases as the hardness of the surgical target portion input from the hardness calculation unit 44 increases. Control the voltage to be applied. Preferably, the voltage control unit 32 controls the voltage applied to the piezoelectric element 401 so that a predetermined excision depth that is set in advance is obtained even when the hardness of the surgical site changes. That is, even when the hardness of the surgical object changes, the voltage applied to the piezoelectric element 401 is controlled so as to maintain a constant incision or excision capability with respect to the surgical object site.

  Here, the voltage control unit 32 calculates a voltage to be applied to the piezoelectric element 401 using a predetermined conversion formula for converting the hardness into a voltage based on the hardness of the surgical target site input from the hardness calculation unit 44. To do. In addition, the voltage control unit 32 determines a voltage to be applied to the piezoelectric element 401 using a predetermined conversion table for converting the hardness into a voltage based on the hardness of the surgical target site input from the hardness calculation unit 44. May be.

Next, the processing executed by the hardness detection means 40 and the voltage control unit 32 in the hardness detection mode will be described in more detail with reference to the drawings.
FIG. 6 is a flowchart illustrating processing executed by the hardness detection unit and the voltage control unit in the hardness detection mode.
Here, the hardness detection means 40 and the voltage control unit 30 are set to the hardness detection mode when the water pulse knife 1 is activated and the operator operates the hardness detection mode changeover switch to the ON state. The process shown in is executed. Further, in the hardness detection mode, the pulsation generator 100 is arranged in a state where pulsating flow is injected to the surgical target site, and the vibration detection unit 42 of the hardness detection means 40 is brought into contact with the surgical target site.

When the operator operates the hardness detection mode changeover switch to the ON state, as shown in FIG. 6, first, in step S1, the detection start instruction unit 41 of the hardness detection means 40 outputs a hardness detection start signal. , Input to the voltage control unit 32 of the control means 30.
Next, in step S <b> 2, the voltage control unit 32 of the control unit 30 inputs the sampling voltage signal to the piezoelectric element 401 of the pulsation generation unit 100 for a predetermined time. Then, when a sampling voltage signal is input to the piezoelectric element 401 of the pulsation generator 100, a predetermined sampling pulsating flow is ejected from the fluid ejection port 212 to the surgical target site for a predetermined time. Further, the vibration of the surgical target site where the predetermined sampling pulsating flow is injected is detected by the vibration detection unit 42 of the hardness detection means 40 and input to the resonance frequency detection unit 43.

  Next, in step S <b> 3, the resonance frequency detection unit 43 of the hardness detection unit 40 detects the resonance frequency of the surgical target site based on the vibration state of the surgical target site input from the vibration detection unit 42. Specifically, the frequency of the pulsating flow when the amplitude of the vibration waveform of the surgical target site input from the vibration detection unit 42 is maximized is set as the resonance frequency. Then, the resonance frequency detection unit 43 inputs the detected resonance frequency of the surgical target site to the hardness calculation unit 44.

Next, in step S <b> 4, the hardness calculation unit 44 of the hardness detection unit 40 calculates the hardness of the surgical target site based on the resonance frequency input from the resonance frequency detection unit 43. Then, the hardness calculation unit 44 inputs the calculated hardness of the surgical target site to the voltage control unit 32 of the control unit 30.
Next, in step S <b> 5, the voltage control unit 32 of the control unit 30 outputs a voltage signal to be input to the piezoelectric element 401 of the pulsation generation unit 100 according to the hardness of the surgical target site input from the hardness calculation unit 44. Set and end the series of processing. In this case, the voltage control unit 32 applies the piezoelectric element 401 so that the pressure of the fluid ejected from the fluid ejection opening 212 increases as the hardness of the surgical target portion input from the hardness calculation unit 44 increases. Set the input voltage signal.

Next, processing performed by the control unit 30 in the normal mode will be described in more detail with reference to the drawings.
FIG. 7 is a flowchart showing the processing executed by the control means in the normal mode.
Here, when the water pulse knife 1 is activated and the operator operates the fluid ejection switch (not shown) to be in the ON state, the control unit 30 enters the normal mode and executes the process shown in FIG.

When the operator operates the fluid ejection switch to be in an ON state, as shown in FIG. 7, first, in step S11, the pump control unit 31 of the control means 30 drives the pump 20 and causes the pulsation generation unit 100 to be constant. The fluid is supplied at a pressure of.
Next, in step S <b> 12, the voltage control unit 32 of the control unit 30 inputs a voltage signal (drive signal) set in the hardness detection mode to the piezoelectric element 401 of the pulsation generation unit 100. As a result, in the pulsation generating unit 100, a pulsed fluid discharge, that is, a pulsating flow is generated in the connection flow path 201, and the generated pulsating flow is ejected from the fluid ejection port 212. That is, the voltage to be applied to the piezoelectric element 401 of the pulsation generator 100 is controlled according to the hardness of the surgical target site input from the hardness calculator 44 of the hardness detector 40.

Next, in step S13, it is determined whether the ON state of the fluid ejection switch is continued. And when it determines with the ON state of a fluid ejection switch continuing (Yes), the process of step S13 is repeated. On the other hand, if it is determined (No) that the ON state of the fluid ejection switch is not continued, the process proceeds to step S14.
Next, in step S <b> 14, the pump control unit 31 of the control unit 30 stops driving the pump 20, and the voltage control unit 32 of the control unit 30 inputs a voltage signal to the piezoelectric element 401 of the pulsation generation unit 100. Is stopped, and a series of processing ends.

Next, the operation of the water pulse knife 1 according to this embodiment will be described.
The fluid discharge of the pulsation generating unit 100 of the water pulse knife 1 according to the present embodiment may be called an inertance L1 on the inlet channel side (sometimes referred to as a synthetic inertance L1) and an inertance L2 on the outlet channel side (called a synthetic inertance L2). Is done by the difference of
First, inertance will be described.
The inertance L is expressed by L = ρ × h / S, where ρ is the density of the fluid, S is the cross-sectional area of the flow path, and h is the length of the flow path. When the pressure difference in the flow path is ΔP and the flow rate of the fluid flowing through the flow path is Q, the relationship of ΔP = L × dQ / dt is derived by modifying the equation of motion in the flow path using the inertance L. It is.

That is, the inertance L indicates the degree of influence on the time change of the flow rate. The larger the inertance L, the less the time change of the flow rate, and the smaller the inertance L, the greater the time change of the flow rate.
In addition, the combined inertance related to the parallel connection of a plurality of flow paths and the series connection of a plurality of flow paths having different shapes is performed by synthesizing the inertance of individual flow paths in the same manner as the parallel connection or series connection of inductances in an electric circuit. Can be calculated.
The inertance L1 on the inlet flow path side is calculated in the range of the inlet flow path 503 because the connection flow path 504 is set to have a sufficiently large diameter with respect to the inlet flow path 503. At this time, since the connection tube connecting the pump 20 and the inlet channel has flexibility, it may be deleted from the calculation of the inertance L1.

Further, the inertance L2 on the outlet flow channel side has a much larger diameter of the connection flow channel 201 than the outlet flow channel, and the pipe portion (tube wall) of the connection flow channel pipe 200 has a small thickness. Minor. Therefore, the inertance L2 on the outlet channel side may be replaced with the inertance of the outlet channel 511.
Note that the thickness of the pipe wall of the connection flow path pipe 200 has sufficient rigidity for the pressure propagation of the fluid.
In this embodiment, the flow path length and cross-sectional area of the inlet flow path 503 and the flow path length and cross-sectional area of the outlet flow path 511 are such that the inertance L1 on the inlet flow path side is larger than the inertance L2 on the outlet flow path side. Set.

Next, the operation of the pulsation generator 100 will be described.
When the operator operates the switch to the ON state and the control unit 30 starts driving the pump 20, the fluid is always supplied to the inlet channel 503 by the pump 20 at a constant hydraulic pressure. As a result, when the piezoelectric element 401 does not operate, the fluid flows into the fluid chamber 501 due to the difference between the discharge force of the pump 20 and the fluid resistance value of the entire inlet channel side.
When the control unit 30 inputs a drive signal to the piezoelectric element 401, the volume of the fluid chamber 501 is changed via the diaphragm 400 as the piezoelectric element 401 expands and contracts.
That is, if a drive signal is input to the piezoelectric element 401 and the piezoelectric element 401 is suddenly expanded, the pressures in the fluid chamber 501 are sufficiently large in the inertances L1 and L2 on the inlet channel side and the outlet channel side. If it does, it will rise rapidly and reach several tens of atmospheres.

Since this pressure is much larger than the pressure by the pump 20 applied to the inlet channel 503, the inflow of fluid from the inlet channel side into the fluid chamber 501 is reduced by the pressure, and the outflow from the outlet channel 511. Will increase. Therefore, there is no need for a check valve provided on the inlet channel side, such as the water pulse knife according to Patent Document 1 described above.
Here, the inertance L1 of the inlet channel 503 is larger than the inertance L2 of the outlet channel 511. Therefore, since the increase amount of the fluid discharged from the outlet channel is larger than the decrease amount of the flow rate of the fluid flowing into the fluid chamber 501 from the inlet channel 503, the pulsed fluid discharge to the connection channel 201, that is, A pulsating flow is generated. The pressure fluctuation at the time of discharge propagates through the connection flow path pipe 200, and the fluid is ejected from the fluid ejection port 212 of the nozzle 211 at the tip.

That is, the pulsation generation unit 100 drives the piezoelectric element 401 to generate pulsation, thereby ejecting the fluid supplied from the pump 20 through the connection flow channel pipe 200 and the nozzle 211 at high speed.
Here, since the diameter of the fluid ejection port 212 of the nozzle 211 is smaller than the diameter of the outlet channel 511, the fluid is ejected as a high-pressure, high-speed pulsed droplet (pulsating flow).
On the other hand, the inside of the fluid chamber 501 is in a vacuum state immediately after the pressure rises due to the interaction between the decrease in the fluid inflow amount from the inlet channel 503 and the increase in the fluid outflow from the outlet channel 511. As a result, after a predetermined time has elapsed due to both the pressure of the pump 20 and the vacuum state in the fluid chamber 501, the fluid in the inlet channel 503 flows toward the fluid chamber 501 at the same speed as before the operation of the piezoelectric element 401. Return.

After the fluid flow in the inlet channel 503 is restored, the pulsating flow from the nozzle 211 can be continuously ejected if the piezoelectric element 401 expands.
Further, in the operation of the pulsation generating unit 100 described above, the fluid chamber 501 has a substantially rotating body shape and includes an inlet channel 503 as a swirling flow generating unit, and the outlet channel 511 has a substantially rotating body shape. Therefore, a swirling flow is generated in the fluid chamber 501, and the bubbles contained in the fluid are quickly discharged from the outlet channel 511 to the outside.
Therefore, even in a minute volume change of the fluid chamber 501 by the piezoelectric element 401, a sufficient pressure increase can be obtained without hindering the pressure fluctuation by the bubbles.

Here, in the water pulse knife 1, in the hardness detection mode, the hardness of the surgical object is detected, and a voltage signal applied to the piezoelectric element 401 of the pulsation generating unit 100 according to the detected hardness of the surgical object part. Set.
In the water pulse knife 1, in the normal mode, the voltage control unit 32 of the control unit 30 controls the piezoelectric element 401 of the pulsation generating unit 100 by the voltage signal set in the hardness detection mode. Thereby, the voltage applied to the piezoelectric element 401 of the pulsation generating unit 100 is controlled according to the hardness of the surgical target site.
Thereby, in the water pulse knife 1, in order to control the change of the volume of the fluid chamber 501 by the piezoelectric element 401 according to the hardness of the surgical target site, a pulsating flow having characteristics suitable for the characteristics of the surgical target site is ejected. Is possible.

In this case, the voltage control unit 32 sets the voltage signal input to the piezoelectric element 401 so that the pressure of the fluid ejected from the fluid ejection opening 212 increases as the hardness of the surgical target site increases. It is possible to more appropriately adjust the pressure of the ejected fluid according to the hardness of the surgical target site.
In addition, since the water pulse knife 1 detects the hardness based on the resonance frequency of the surgical target site, it is possible to easily detect the hardness of the surgical target site.
It should be noted that the present invention is not limited to the above-described embodiment, but includes modifications and improvements as long as the object of the present invention can be achieved.

For example, in the above-described embodiment, as a method of detecting the hardness of the surgical target part, a predetermined sampling pulsating flow is jetted to the surgical target part for a predetermined time, and vibration of the surgical target part injected with the predetermined sampling pulsating flow is performed. A method of detecting the resonance frequency from the frequency and calculating the hardness based on the resonance frequency is adopted. However, a method of calculating the hardness of the surgical target part by bringing a probe that vibrates ultrasonically into contact with the surgical target part and detecting a change in the resonance frequency of the probe may be adopted.
Further, in the above-described embodiment, the configuration includes one pulsation generation unit 100 that ejects fluid, but the configuration may include a plurality of pulsation generation units 100.

It is a schematic block diagram which shows the water pulse knife which concerns on embodiment of this invention. It is sectional drawing which shows the pulsation generation | occurrence | production part of the water pulse knife shown in FIG. It is a perspective view which shows the outline of the state which decomposed | disassembled the pulsation generation | occurrence | production part shown in FIG. It is a top view which shows the inlet flow path of the pulsation generation | occurrence | production part shown in FIG. 2, and represents the state which visually recognized the upper case from the joint surface side with a lower case. It is a schematic block diagram of a hardness detection means and a control means. It is a flowchart which shows the process which a hardness detection means and a voltage control part perform in hardness detection mode. It is a flowchart which shows the process which a control means performs in normal mode.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Water pulse knife (fluid ejection apparatus, fluid ejection surgical instrument), 20 Pump (fluid supply means), 30 Control means, 40 Hardness detection means, 42 Vibration detection part (resonance frequency detection means), 43 Resonance frequency detection part ( Resonance frequency detecting means), 100 pulsation generating section, 200 connection flow path pipe (flow path pipe), 201 connection flow path, 212 fluid ejection opening (fluid ejection opening), 401 piezoelectric element (volume changing means), 501 fluid chamber 503, inlet channel, 511 outlet channel.

Claims (6)

A pulsation generator having a fluid chamber into which fluid flows and a volume changing means for changing the volume of the fluid chamber;
A channel tube having a connection channel communicating with the fluid chamber and the fluid ejection port;
Fluid supply means for supplying fluid to the fluid chamber;
Control means for controlling the change in volume of the fluid chamber by the volume changing means;
Hardness detection means for detecting the hardness of a fluid ejection object that ejects fluid, and
The fluid ejecting apparatus according to claim 1, wherein the control unit controls the change of the volume of the fluid chamber by the volume changing unit according to the hardness detected by the hardness detecting unit. The hardness detection means includes
Resonance frequency detection means for detecting the resonance frequency of the fluid ejection object,
The fluid ejecting apparatus according to claim 1, wherein hardness of a fluid ejecting object that ejects fluid is detected based on the resonance frequency detected by the resonance frequency detecting unit. The volume changing means is a piezoelectric element,
The fluid ejecting apparatus according to claim 1, wherein the control unit controls a voltage applied to the piezoelectric element according to the hardness detected by the hardness detection unit.   The control means controls the change of the volume of the fluid chamber by the volume change means so that the pressure detected by the fluid detection port increases as the hardness detected by the hardness detection means increases. The fluid ejecting apparatus according to claim 1, wherein the fluid ejecting apparatus includes: A pulsation generator having a fluid chamber into which fluid flows and a volume changing means for changing the volume of the fluid chamber;
A channel tube having a connection channel communicating with the fluid chamber and the fluid ejection port;
Fluid supply means for supplying fluid to the fluid chamber;
Control means for controlling the change in volume of the fluid chamber by the volume changing means;
A hardness detecting means for detecting the hardness of the surgical target site that ejects the fluid, and
The control means controls the change of the volume of the fluid chamber by the volume changing means according to the hardness detected by the hardness detecting means,
The fluid ejecting surgical instrument characterized in that the volume changing means changes the volume of the fluid chamber to incise or excise the surgical target site by the fluid ejected from the fluid ejection port. Supply fluid to the fluid chamber communicating with the connection flow path,
By changing the volume of the fluid chamber, the pressurized fluid is ejected from the fluid ejection port communicating with the connection flow path,
Detect the hardness of the fluid ejection target that ejects the fluid,
According to the detected hardness, a change in the volume of the fluid chamber is controlled.

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