JP2009108866A - Fluid jet device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid jet device which has a high degree of reliability by a simple structure. <P>SOLUTION: An extremely small fluid chamber 113 communicates with a fluid jet opening 115 by means of an output flow-path 112, at least one face of the fluid chamber 113 is formed of a diaphragm 131 pasted with a piezoelectric element 141. The inertance L1 of an inlet flow path 114 of the fluid chamber 113 is made larger than the inertance L2 of the output flow path 112. By supplying fluid through a connection tube 201 from a pressure-generating part 401, a small pulsation generator 101 can be arranged at the tip of the fluid jet device 1. Thus, a high-speed pulsive fluid can be ejected at a high frequency, and a small fluid jet device 1 can be provided which is applicable to the tip of a catheter and the like. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fluid ejecting apparatus that ejects fluid with strong and high-frequency pulsation while being small and lightweight.

  Conventionally, as a fluid ejecting apparatus for incising or excising biological tissue, it has means for allowing fluid to flow into the fluid chamber, and by intermittently generating fluid vapor bubbles by heating means within the fluid chamber, There is known a method for generating a fluid jet that intermittently raises an internal pressure and ejects a pulsating fluid at a high speed (for example, Patent Document 1).

Special table 2003-500098 gazette

According to Patent Document 1, a fluid is instantaneously heated by discharge of a high voltage electrode or the like, and a high-speed fluid jet is generated by the generated pressure. The generated fluid jet can selectively excise the soft tissue of a living body in surgery or the like.
However, since the fluid ejecting apparatus according to Patent Document 1 ejects a fluid by a fluid vapor bubble, the fluid to be ejected is heated. Therefore, it can be considered that the heat adversely affects normal tissues and the like. Furthermore, since the next injection cannot be performed until the vapor bubble disappears, the actual drive frequency is limited to about 100 Hz.

In addition, Patent Document 1 describes an application example in which a piezoelectric element is used as an ejecting unit in the detailed description of the invention, but does not describe a specific implementation.
In addition, for the purpose of providing a fluid ejection opening at the distal end of the catheter and using it to remove a thrombus in a blood vessel by ejecting the fluid, it is necessary to eject the fluid from the distal end of a thin and flexible tube. There is a problem that it is possible and cannot be used.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

Application Example 1 A fluid ejecting apparatus according to this application example includes a fluid chamber whose volume can be changed, an inlet channel that communicates with the fluid chamber and has a volume smaller than that of the fluid chamber, the fluid chamber, A pulsation generating section provided with an outlet flow path communicating with the fluid ejection opening and having an inertance set smaller than the inlet flow path; and a pressure generating section for supplying fluid to the inlet flow path. It is characterized by.
Here, as the pressure generating unit, for example, a pump that discharges fluid at a predetermined pressure can be employed.

  According to this application example, since the volume of the inlet channel is smaller than the fluid chamber, even if the volume change of the fluid chamber is small, the influence of the volume change of the gas contained in the fluid or the fluid itself can be minimized. The pressure inside the fluid chamber can be increased instantaneously. Due to the difference in the pressure rise and the inertance between the inlet channel and the outlet channel, the fluid can be efficiently ejected with strong pulsation.

  In addition, by providing a pump or the like that discharges fluid at a predetermined pressure, there is an effect that stable operation is possible.

  Application Example 2 In the fluid ejecting apparatus according to the application example described above, it is preferable that the channel length of the outlet channel is equal to or less than the outer diameter of the pulsation generating section cross section orthogonal to the outlet channel.

  By doing so, the length of the outlet channel, that is, the distance between the fluid ejection opening and the fluid chamber is shortened, so that the pulsation generated in the fluid chamber is transmitted to the fluid ejection opening without being attenuated, and efficiently. Fluid can be ejected with strong pulsation.

  Application Example 3 In the fluid ejecting apparatus according to the application example described above, the pulsation generating unit includes a volume changing unit that changes a volume of the fluid chamber, and the volume changing unit covers one surface of the fluid chamber. It is preferable to include a diaphragm to be sealed and a piezoelectric element that is attached to the diaphragm and deforms the diaphragm.

  By doing so, a small unimorph type piezoelectric actuator is configured as the volume changing means, and high frequency pulsation can be generated by its high speed operation while having a simple structure.

  Application Example 4 In the fluid ejecting apparatus according to the application example described above, the pulsation generating unit includes a volume changing unit that changes the volume of the fluid chamber, and the volume changing unit is configured so as to face the fluid chamber. It is preferable to include a diaphragm that seals the respective surfaces, and a piezoelectric element attached to the diaphragm.

  In this way, it is possible to change the volume of the fluid chamber twice as much as in the case where the diaphragm is formed on one surface while keeping the volume of the pulsation generating portion small, and to generate stronger pulsation. Is possible. On the contrary, when the volume change may be small, there is an effect that a smaller pulsation generator can be configured.

  Application Example 5 In the fluid ejecting apparatus according to the application example described above, at least one of the inlet channel and the outlet channel is a channel formed by a hole formed in a side wall constituent member of the fluid chamber. Is preferred.

  With such a structure, the fluid ejecting apparatus can be configured with a simple structure without providing a new additional element such as a pipe.

  Application Example 6 In the fluid ejecting apparatus according to the application example described above, at least one of the inlet channel or the outlet channel is a channel configured by a groove and a diaphragm of a side wall constituent member of the fluid chamber. Preferably there is.

  According to this configuration, a desired flow path cross-sectional area and flow path length can be realized without the need for a special machine tool or tool in the formation of an inlet flow path that requires a particularly thin and long flow path.

  Application Example 7 In the fluid ejecting apparatus according to the application example described above, at least one of the inlet channel or the outlet channel is formed of two side wall constituent members joined on a plane substantially parallel to the diaphragm. A flow path constituted by a groove formed on the joint surface is preferable.

  According to such a configuration, for example, a circular flow path can be formed by forming a semicircular groove in the joint surface of both of the two side wall structural members. There is an effect that the area, the channel length, the channel cross-sectional shape, and the like can be configured to optimum values by a simple processing method.

  Application Example 8 In the fluid ejecting apparatus according to the application example described above, it is preferable that the fluid ejection device includes a cover member that covers the pulsation generation unit.

  Thus, by providing the cover member, it is possible to protect the pulsation generating part and reduce the possibility of damaging the surgical part even when the tip of the fluid ejection device touches the surgical part during surgery or the like.

  Application Example 9 In the fluid ejecting apparatus according to the application example described above, it is preferable that the pulsation generating unit is fixed to a distal end of a flexible tube.

  According to such a configuration, since a catheter-like fluid ejecting apparatus having a small pulsation generating portion provided at the distal end of a flexible tube can be configured, a thrombus or the like can be removed by being inserted into a blood vessel and ejecting fluid. Treatment is possible.

  Application Example 10 In the fluid ejecting apparatus according to the application example described above, it is preferable that the pulsation generating unit is fixed to a distal end of a hard pipe having a diameter substantially equal to or smaller than the pulsation generating unit.

  According to such a configuration, when performing an operation on a fine part, the operator can grasp the upstream side of the hard pipe, thereby inserting the tip of the fluid ejection device into a narrow surgical part.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 4 show a fluid ejection device and a pulsation generator according to Embodiment 1, FIGS. 5 and 6 show Embodiment 2, FIG. 7 shows Embodiment 3, and FIG. 8 shows a pulsation generator according to Embodiment 4. FIG. 9 shows a fluid ejecting apparatus according to the fifth embodiment.
In addition, the figure referred in the following description is a schematic diagram in which the vertical and horizontal scales of members or portions are different from actual ones for convenience of illustration.
In addition, the fluid ejecting apparatus according to the present invention can be used in various ways such as drawing using ink, washing fine objects and structures, scalpels, etc. In the embodiments described below, A fluid ejecting apparatus suitable for installation at the distal end of a catheter used for the purpose of inserting and removing a thrombus or the like, or a fluid ejecting apparatus suitable for incising or excising living tissue will be described as an example. Therefore, the fluid used in the embodiment is water or physiological saline.
(Embodiment 1)

  FIG. 1 is an explanatory diagram illustrating a schematic configuration of the fluid ejecting apparatus according to the first embodiment. In FIG. 1, a fluid ejecting apparatus 1 contains a fluid as a basic configuration and discharges the fluid at a predetermined pressure by the action of a pump or the like, and changes the fluid supplied at the predetermined pressure into pulsation. The pulsation generator 101 and the flexible connection tube 201 connecting the pressure generator 401 and the pulsation generator 101 are configured. Note that wiring necessary for driving the pulsation generator 101 is installed along the connection tube 201 (not shown).

Next, the pulsation generator 101 according to the first embodiment will be described with reference to FIGS. 2 is a longitudinal sectional view of a pulsation generating portion of the fluid ejecting apparatus according to the first embodiment of the present invention, FIG. 3 is a perspective view of a flow path forming member, and FIG. 4 is a perspective view of a main portion of the pulsation generating portion.
2 and 3, the pulsation generating unit 101 includes a flow path forming member 111 in which a concave portion constituting the fluid chamber 113 is formed. Here, the flow path forming member 111 is a side wall constituting member constituting the side wall of the fluid chamber 113. The flow path forming member 111 constituting the side wall of the fluid chamber 113 is perforated with an inlet flow path 114 having one end communicating with the fluid chamber 113 and the other end communicating with the connection tube 201. Further, an outlet channel 112 having one end communicating with the fluid chamber 113 and the other end communicating with the outside of the fluid chamber 113 is drilled on the side wall of the fluid chamber 113 facing the side wall where the inlet channel 114 is perforated. . Of both ends of the outlet channel 112, one end communicating with the outside of the fluid chamber 113 serves as a fluid ejection opening 115 through which fluid is ejected. The length of the outlet channel 112 is set to be sufficiently smaller than the maximum outer diameter of the pulsation generator 101.

  2 and 4, one surface of the fluid chamber 113 is sealed with a diaphragm 131. In addition, a piezoelectric element 141 is attached to the diaphragm 131 in advance. The piezoelectric element 141 has a diaphragm 131 as one electrode, and an electrode member (not shown) is formed on the other surface facing the diaphragm 131 as a reverse electrode. The wiring from these electrodes is arranged along the connection tube 201 as described above (not shown). Further, the cover member 121 is fixed to the flow path forming member 111 while maintaining a sufficient gap so as not to hinder the operation of the diaphragm 131 and the piezoelectric element 141.

  Next, an outline of fluid flow in the fluid ejecting apparatus 1 will be briefly described. A pressure container 401 contains a fluid container and a pump (both not shown) connected to the fluid container. The pump is connected to deliver fluid to the connecting tube 201. The fluid stored in the fluid container is supplied to the inlet channel 114 through the connection tube 201 at a constant pressure by a pump. Further, the fluid is discharged from the fluid ejection opening 115 through the fluid chamber 113 and the outlet channel 112. However, fluid ejection when the piezoelectric element 141 is not driven is a continuous flow, and its speed is slow.

  Next, the operation in the present embodiment will be described with reference to FIGS. The fluid discharge of the pulsation generating unit 101 of the present embodiment is called an inertance L1 on the inlet channel side (sometimes referred to as a combined inertance L1 on the inlet channel side) and an inertance L2 on the outlet channel side (a combined inertance L2 on the outlet channel side). It 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 obtained by combining the inertance of individual flow paths in the same way as the parallel connection or series connection of inductances in an electric circuit. Can be calculated.

In addition, since the connection tube 201 that connects the pressure generation unit 401 and the inlet channel has flexibility, it may be deleted from the calculation of the inertance L1 on the inlet channel side.
In this embodiment, the flow path length and cross-sectional area of the inlet flow path 114 and the flow path length and cross-sectional area of the outlet flow path 112 are set so 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 101 will be described.
The fluid is always supplied to the inlet channel 114 by the pressure generator 401 at a constant hydraulic pressure. As a result, when the piezoelectric element 141 does not operate, the fluid flows out from the fluid ejection opening 115 due to the fluid resistance of the inlet channel 114, the fluid chamber 113, and the outlet channel 112 and the above-described hydraulic pressure. This fluid outflow is very slow and does not have the ability to cut or excise living tissue.

  Here, if a drive signal is input to the piezoelectric element 141 and the piezoelectric element 141 contracts suddenly, the diaphragm 131 bends in a convex shape in a direction that reduces the volume of the fluid chamber 113. As a result, the pressure in the fluid chamber 113 rises rapidly to reach several atmospheres if the inertances L1 and L2 on the inlet channel side and the outlet channel side have a sufficient size.

Since this pressure is much larger than the pressure generated by the pressure generation unit 401 applied to the inlet channel 114, the inflow of fluid from the inlet channel side into the fluid chamber 113 is reduced by the pressure, and from the outlet channel 112. Outflow increases. However, since the inertance L1 of the inlet channel 114 is larger than the inertance L2 of the outlet channel 112, the increase in the outflow from the outlet channel 112 is greater than the decrease in the amount of fluid flowing into the fluid chamber 113 from the inlet channel side. The amount is large.
As a result, pulsed fluid discharge, that is, high-speed pulsed fluid 901 is ejected from the fluid ejection opening 115 through the outlet channel 112.

  On the other hand, the inside of the fluid chamber 113 is in a low pressure state or a vacuum state immediately after the pressure increase due to the interaction between the decrease in the fluid inflow amount from the inlet channel 114 and the increase in the fluid outflow amount from the outlet channel 112. As a result, the flow rate of the fluid in the inlet channel 114 returns to the same speed as before the operation of the piezoelectric element 141 after a predetermined time has elapsed due to both the pressure of the pressure generating unit 401 and the low pressure or vacuum state in the fluid chamber 113. To do. If the piezoelectric element 141 contracts after the fluid flow in the inlet channel 114 is restored, high-speed pulsed fluid can be continuously ejected from the fluid ejection opening 115.

  Therefore, according to the first embodiment described above, since the fluid is stably supplied to the inlet flow path 114 at a constant pressure by the pressure generation unit 401, the priming operation or the like in the initial operation is unnecessary, and the drive starts. From this, it is possible to perform ejection of a desired fluid amount.

  The supply pressure from the pressure generator 401 is generally set to 1 atm or less (0.1 Mpa), preferably 0.3 atm (0.03 MPa) or less. When the fluid ejecting apparatus 1 is used at the tip of a catheter or the like, the pulsation generating unit 101 needs to be inserted along the blood vessel. Therefore, the connecting tube 201 is preferably as flexible as possible. For that purpose, it is preferable to use a thin tube and to make the pressure low as long as the fluid can be fed to the pulsation generator 101. For this purpose, it is necessary to set the resistances of the inlet channel 114, the fluid chamber 113, and the outlet channel 112 as small as possible.

  Also, especially when used in brain surgery or catheters, when there is a risk that a device failure may cause a serious accident, it is necessary to avoid high-pressure fluid from being ejected when the connection tube 201 is disconnected. Not only that, it is required to keep the pressure low.

The diameter of the pulsation generating unit 101 is 3 mm or less, preferably 2 mm or less when used for brain surgery that requires excision of a fine part. Furthermore, when using for a catheter etc., it is 2 mm or less, Preferably it is 1 mm or less. Further, the length is required to be 20 mm or less, preferably 10 mm or less so as not to prevent free bending.
Therefore, the diaphragm 131 and the piezoelectric element 141 become very small, and the area contributing to the volume change of the fluid chamber 113 of the diaphragm 131 is generally 20 square mm or less, and generally 10 square mm or less. Further, the amount of displacement is preferably 100 μm or less.

  Therefore, in order to effectively use this minute volume change for fluid injection, the amount of increase in outflow from the outlet channel 112 is made larger than the amount of decrease in inflow of fluid into the fluid chamber 113 from the inlet channel side. There is a need. Therefore, the inertance L1 of the inlet flow path 114 is set larger than the inertance L2 of the outlet flow path 112, and the ratio is 5 times or more, preferably 10 times or more.

  Further, by setting the volume of the inlet channel 114 to be smaller than the volume of the fluid chamber 113, a minute volume change of the fluid chamber 113 can be caused by compression due to a rise in fluid pressure in the inlet channel 114, or by the inlet channel 114. Loss is reduced by expanding the volume due to deformation of the surrounding members.

  The length of the outlet channel 112, that is, the channel length from the fluid ejection opening 115 to the fluid chamber 113 is set to be equal to or less than the maximum diameter of the pulsation generating unit 101. As described above, since the volume change amount of the fluid chamber 113 changes according to the maximum outer diameter of the pulsation generating portion, the outlet flow path is shorter and less lossy for the pulsation generating portion having a small maximum outer diameter. Is required.

  Specifically, the length of the outlet channel 112 is set to approximately 1 mm or less, desirably 0.5 mm or less. Accordingly, the distance between the fluid ejection opening 115 and the fluid chamber 113 is shortened, and the pulsation generated in the fluid chamber is transmitted to the fluid ejection opening 115 without being attenuated, so that the fluid can be ejected efficiently with strong pulsation. Furthermore, setting the length of the outlet channel 112 to be short will reduce the inertance L2 of the outlet channel 112 described above, so that more efficient fluid injection can be performed.

  Further, the cross-sectional area of the fluid ejection opening 115 may be smaller than the cross-sectional area of the outlet channel 112. By doing in this way, the ejection speed of the fluid from the fluid ejection opening 115 can be improved without causing an increase in channel resistance or inertance of the outlet channel. In brain surgery or the like, there is also an advantage that precise surgery can be performed because the jet fluid becomes smaller.

  Further, by adopting a structure in which the piezoelectric element 141 and the diaphragm 131 are adopted as the volume changing means, the structure can be simplified and the size can be reduced accordingly. Further, the maximum frequency of volume change of the fluid chamber 113 can be set to a high frequency of 1 to 10 KHz or more, which is optimal for high-speed pulsating flow injection.

  Further, since the inlet channel 114 and the outlet channel 112 are formed on the side wall of the fluid chamber 113, the number of parts is not increased. Further, since the periphery of the diaphragm 131 and the fixing surface of the flow path forming member 111 can be formed smoothly, the fluid chamber 113 can be reliably sealed. For fixing the diaphragm 131 and the flow path forming member 111, methods such as adhesion, laser welding of the peripheral portion, and diffusion bonding can be used.

In this embodiment, the fluid chamber 113 formed as a concave portion of the flow path forming member 111 has a rectangular parallelepiped shape. However, by smoothly rounding the corners, durability can be improved due to retention of bubbles and relaxation of stress concentration on the diaphragm. I can hope.
(Embodiment 2)

Next, the fluid ejecting apparatus according to the second embodiment will be described with reference to the drawings.
In the second embodiment, the diaphragm with the piezoelectric element attached is provided opposite to the fluid chamber, and the fluid chamber is sealed by the diaphragm, thereby enabling a large volume change while the fluid chamber is small, A stronger fluid can be ejected. The same functional parts as those in the first embodiment will be described with the same reference numerals as those in the first embodiment. Further, the description of the same operation is omitted.
FIG. 5 is a partial cross-sectional view showing a pulsation generator according to the second embodiment, and FIG. 6 is a perspective view of a main part of the pulsation generator.

  5 and 6, the pulsation generator 301 includes a flow path forming plate 311 formed of a metal having high anticorrosion properties such as stainless steel or ceramics. In the flow path forming plate 311, a through hole constituting the fluid chamber 313 is opened in the thickness direction. Here, the flow path forming plate 311 is a side wall constituting member constituting the side wall of the fluid chamber 313. The flow path forming plate 311 constituting the side wall of the fluid chamber 313 is perforated with an inlet flow path 314 having one end communicating with the fluid chamber 313 and the other end communicating with the connection tube 201 substantially parallel to the plate surface. . In addition, an outlet channel 312 having one end communicating with the fluid chamber 313 and the other end communicating with the outside of the fluid chamber 313 is drilled in the side wall of the fluid chamber 313 facing the side wall with the inlet channel 314 drilled. . One end of the outlet channel 312 communicating with the outside of the fluid chamber 313 is a fluid ejection opening 315 from which fluid is ejected.

The thickness of the flow path forming plate 311 is 0.1 mm or more at which an inlet flow path or an outlet flow path having a diameter of 0.05 mm or more can be formed inside, and there is sufficient fluid for changing the volume of a minute pressure chamber. It is set to 1 mm or less as long as the rigidity of the fluid chamber is maintained.
In addition, diaphragms 131 are fixed to both surfaces of the flow path forming plate 311 to seal the fluid chamber 313. A piezoelectric element 141 is attached to the surface of the diaphragm 131 opposite to the fluid chamber 313. One electrode of the piezoelectric element 141 is a diaphragm 131, and the other electrode is formed by providing an electrode member on the other surface facing the diaphragm 131. The wirings from the diaphragm 131 and the wirings from the electrode members are combined and arranged along the connection tube 201 (not shown).

  Cover members 321 having sufficient gaps are provided on both surfaces of the flow path forming plate 311 so as not to hinder the movement of the diaphragm 131 and the piezoelectric element 141, and the piezoelectric element 141 and the like are sealed and protected from the outside. At the same time, safety is ensured when the tip touches the surgical site during surgery.

Next, the operation of the pulsation generator 301 having the above-described configuration will be described. As in the first embodiment, the fluid from the pressure generator is supplied to the inlet channel 314 at a constant pressure.
Here, when a drive signal is input to the piezoelectric element 141 and the piezoelectric element 141 contracts suddenly, the diaphragms 131 on both surfaces of the fluid chamber 313 are rapidly bent in a convex shape in the direction of reducing the volume of the fluid chamber 313. As a result, the pressure in the fluid chamber 313 rises rapidly and reaches several atmospheres if the inertances L1 and L2 on the inlet channel side and the outlet channel side have a sufficient size.

  Since this pressure is much larger than the pressure generated by the pressure generation unit 401 applied to the inlet channel 314, the inflow of fluid from the inlet channel side into the fluid chamber 313 is reduced by the pressure, and from the outlet channel 312. Outflow increases. However, since the inertance L1 of the inlet channel 314 is larger than the inertance L2 of the outlet channel 312, the amount of outflow from the outlet channel 312 is reduced due to the decrease in the amount of fluid flowing into the fluid chamber 313 from the inlet channel side. Large increase.

  In the above-described operation, the diaphragm 131 of the second embodiment reduces the volume of the fluid chamber 313 from both surfaces of the fluid chamber 313, so that the volume change amount is large, and fluid ejection with stronger pulsation compared to the first embodiment. Is possible.

Further, when the jetting strength of the pulsating fluid is the same as in the first embodiment, the area of the diaphragm can be further reduced, and the pulsation generating unit can be downsized. The range of application is expanded to the treatment in minute blood vessels. Further, a fluid ejecting apparatus that is more suitable for fine excision as in brain surgery can be configured.
(Embodiment 3)

Next, Embodiment 3 will be described with reference to the drawings. Embodiment 3 is characterized in that at least one of an inlet channel and an outlet channel is formed by a groove formed in a channel forming plate and a diaphragm.
FIG. 7 is a vertical cross-sectional view of the main part of the pulsation generating unit according to the third embodiment. Except for the formation structure of the inlet channel and the outlet channel, the structure is the same as that of the above-described second embodiment, and thus the description thereof will be omitted, and the same functional parts will be described with the same reference numerals as those of the second embodiment.

  In the flow path forming plate 511, a through-hole is formed in the thickness direction as in the second embodiment to form a fluid chamber 313. In addition, a U-shaped groove portion that forms an outlet channel 512 is provided on one surface. The same applies to the inlet channel (not shown). By fixing the diaphragm 331 to the flow path forming plate 511, the upper surface of the U-shaped groove is sealed, and the outlet flow path 512 is formed.

  The shape of the groove is not limited to a U-shape, and a square shape, an arc shape, or the like can be selected. However, it is desirable that the corners have a smooth cross section so that bubbles do not easily stay. In addition, the present embodiment can be applied to the structure of the first embodiment described above by machining a groove on the flow path forming member.

According to this structure, it is not necessary to process an inlet channel having a small cross-sectional area with a special drill or the like, and the fluid ejecting apparatus can be easily configured.
(Embodiment 4)

Next, a fourth embodiment will be described with reference to the drawings. The fourth embodiment is characterized in that the flow path forming plate of the second embodiment described above is divided into two parts in the thickness direction, and at least one of the inlet flow path or the outlet flow path is formed by a groove provided on the joint surface. And
FIG. 8 is a vertical cross-sectional view of the main part of the pulsation generating unit according to the fourth embodiment. Except for the method of forming the inlet channel and the outlet channel, the structure is the same as that of the above-described second embodiment, so that the description thereof will be omitted, and the same functional parts will be described with the same reference numerals as those of the second embodiment.

  A through hole is formed in the flow path forming plate 711 in the thickness direction as in the second embodiment, and the fluid chamber 313 is formed by joining the two flow path forming plates 711 together. A groove having a semicircular cross section is provided on the facing surface of the flow path forming plate 711, and an outlet flow path 712 having a circular cross section is formed after the two are bonded. The same applies to the inlet channel (not shown).

According to this structure, there is an effect that an inlet channel and an outlet channel having arbitrary shapes can be easily formed without using a special drill or the like depending on the shape of the groove provided in the channel forming plate 711. The present embodiment can also be applied as a combination of a grooved flow path forming member and a grooved flow path forming plate in the structure of the first embodiment described above.
(Embodiment 5)

  Next, a fifth embodiment of the present invention will be described with reference to the drawings. Embodiment 5 is characterized in that the pulsation generating part is fixed to the tip of a hard pipe having a diameter substantially equal to or smaller than that of the pulsation generating part. Since the internal structure and operation of the pulsation generating unit other than the method for fixing the pulsation generating unit are the same as those in the first to fourth embodiments, description thereof will be omitted.

  FIG. 9 is an explanatory diagram of a fluid ejecting apparatus according to the fifth embodiment. In FIG. 9, a flexible connection tube 201 to which a fluid is sent from the pressure generation unit 401 is connected to a hard tube 601 at a gripping unit 602. The hard tube 601 has substantially the same diameter as the pulsation generating unit 101 or a smaller diameter. High-speed pulsed fluid 901 is ejected from the pulsation generator 101.

  Therefore, according to the present embodiment, the fluid ejection opening can be directed to an arbitrary position, and the diameter of the hard tube 601 is equal to or less than that of the pulsation generation unit 101. Easy to do. Further, by manufacturing the hard tube 601 with a metal or a composite material of a resin and a metal, it is possible to bend the hard tube 601 arbitrarily according to the surgical site and adapt it to the operation.

FIG. 3 is an explanatory diagram illustrating a schematic configuration of the fluid ejecting apparatus according to the first embodiment. FIG. 3 is a longitudinal sectional view of a pulsation generating unit according to the first embodiment. FIG. 3 is a perspective view of a flow path forming member of the pulsation generating unit according to the first embodiment. FIG. 3 is a perspective view of a main part of a pulsation generating unit according to the first embodiment. FIG. 9 is a partial cross-sectional view showing a pulsation generating unit according to Embodiment 2. FIG. 6 is a perspective view of a main part of a pulsation generating unit according to a second embodiment. FIG. 6 is a longitudinal sectional view of a main part of a pulsation generating unit according to a third embodiment. FIG. 9 is a longitudinal sectional view of a main part of a pulsation generating unit according to a fourth embodiment. FIG. 9 is an explanatory diagram of a fluid ejection device according to a fifth embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Fluid injection apparatus, 112 ... Outlet flow path, 113 ... Fluid chamber, 114 ... Inlet flow path, 115 ... Fluid injection opening part, 131 ... Diaphragm, 141 ... Piezoelectric element, 201 ... Connection tube, 401 ... Pressure generation part

Claims (10)

A fluid ejection device that includes a fluid ejection opening and ejects fluid from the fluid ejection opening,
A fluid chamber whose volume can be changed, an inlet flow channel communicating with the fluid chamber and having a smaller volume than the fluid chamber, and an inertance communicating with the fluid chamber and the fluid ejection opening from the inlet flow channel. A pulsation generator comprising an outlet channel set small;
A pressure generator for supplying fluid to the inlet channel;
A fluid ejecting apparatus comprising: The fluid ejection device according to claim 1,
The fluid ejecting apparatus according to claim 1, wherein a flow path length of the outlet flow path is equal to or less than an outer diameter of a pulsation generating section cross section orthogonal to the outlet flow path. The fluid ejection device according to claim 1 or 2,
The pulsation generating unit includes volume changing means for changing the volume of the fluid chamber,
The volume changing means includes a diaphragm that seals one surface of the fluid chamber, and a piezoelectric element that is attached to the diaphragm and deforms the diaphragm. The fluid ejection device according to any one of claims 1 to 3,
The pulsation generating unit includes volume changing means for changing the volume of the fluid chamber,
The fluid ejecting apparatus according to claim 1, wherein the volume changing unit includes a diaphragm that seals two opposing surfaces of the fluid chamber, and a piezoelectric element attached to the diaphragm. In the fluid ejection device according to any one of claims 1 to 4,
At least one of the inlet channel or the outlet channel is a channel formed by a hole formed in a side wall constituting member of the fluid chamber. The fluid ejection device according to any one of claims 1 to 5,
At least one of the inlet channel or the outlet channel is a channel formed by a groove formed in a side wall constituting member of the fluid chamber and the diaphragm. The fluid ejection device according to any one of claims 1 to 6,
At least one of the inlet channel or the outlet channel is a channel formed by a groove formed on a joint surface of two side wall constituent members joined by a surface substantially parallel to the diaphragm. A fluid ejecting apparatus. The fluid ejection device according to any one of claims 1 to 7,
A fluid ejecting apparatus comprising a cover member that covers the pulsation generating portion. The fluid ejection device according to any one of claims 1 to 8,
The fluid ejecting apparatus according to claim 1, wherein the pulsation generator is fixed to a distal end of a flexible tube. The fluid ejection device according to any one of claims 1 to 8,
The fluid ejecting apparatus, wherein the pulsation generating unit is fixed to a tip of a hard pipe having a diameter substantially equal to or less than the pulsation generating unit.

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