JP2005152127A - Fluid injection device and its driving method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid injection device improving its capacity of incising a biotissue, capable of incising only an affected tissue while preserving the vascular tissue such as a blood vessel, and securing the visual field of an operation field by reducing the generation and residual of bubbles and to provide its driving method. <P>SOLUTION: This fluid injection device 10 is provided with a micro pump 100 including a pump chamber 132, changing the volume of the pump chamber 132 and delivering the fluid, a connecting channel 201 having an opening part 211 which has one end connected to an outlet channel of the micro pump 100 and the other end formed smaller than the diameter of the outlet channel, and a connecting channel tube 200 bored with the connecting channel 201 and having the rigidity capable of transmitting the pulsation of the fluid made to flow from the micro pump 100 to the opening part 211. The fluid is made to flow by the repetition of the pulsating wave group and a suspension part, and injected from the opening part 211 at a high speed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention particularly relates to a fluid ejecting apparatus suitable for incising or excising living tissue and a driving method thereof.

Conventionally, surgery using a jetted fluid can incise the organ parenchyma while preserving the vasculature such as blood vessels, and the incidental damage to living tissue other than the incision is minimal. Since the burden on the patient is small and the bleeding is small, the bleeding does not interfere with the field of view of the operative field, so that a rapid operation is possible.

For example, a pump as a liquid pressurizing source is provided outside, and a liquid such as physiological saline pressurized by the pump is injected endoscopically from the distal end of the tube with a flexible tube. A fluid ejecting apparatus is known as an endoscopic surgical apparatus that performs incision or the like (see, for example, Patent Document 1).

Further, there is known a fluid ejecting apparatus that includes a steam generating means in a chamber and ejects fluid in a pulsating manner by a high-pressure steam bubble generated by the steam generating means (see, for example, Patent Document 2). ).

JP 63-99853 A (page 3, FIG. 1) Japanese translation of PCT publication No. 2003-500098 (page 8, FIG. 1)

In such a patent document 1, since a pump as a pressurizing source of liquid (fluid) is provided outside and a high-pressure fluid is guided to a treatment section with a flexible tube, pressure pulsation is temporarily generated by the pressurizing source. Even so, the fluid is jetted continuously because of the elasticity of the tube. As will be described in detail later, when the fluid ejection pulsates, the incision ability is enhanced by the impact of the leading wave. on the other hand,
In continuous flow, the incision ability of the living tissue is not sufficient, and the flow rate to be ejected increases,
It is thought that splashes of living tissues and the like are likely to fly from the incision, and this splash may infect the practitioner.
In addition, since the flow rate of the fluid is large, bubbles are likely to be generated in the treatment portion, and since the bubbles are difficult to disappear because of the continuous flow, there is a problem that the field of view of the surgical field is hindered.

In Patent Document 2, the fluid can be ejected by a pulsating fluid by the steam generating means.
In the fluid ejection by the steam generating means, it is difficult to control the ejection speed and flow rate, and it is difficult to efficiently incise various treatment parts of the human body.
In addition, when vapor is generated, the chamber (micro liquid chamber) is very small, so the temperature of the fluid rises, and thermal tissue changes around the incision and alteration of the fluid itself are considered, and there is a problem with safety. .

The purpose of the present invention is to increase the incision ability of living tissue, incision can be made only on the diseased tissue while preserving the vascular tissue such as blood vessels, etc., and the field of view of the surgical field is secured by reducing the generation and remaining of bubbles A fluid ejecting apparatus that can be used and a driving method thereof.

The fluid ejection device of the present invention includes a pump chamber, a micro pump that changes the volume of the pump chamber to perform a fluid discharge operation, and one end connected to an outlet flow path of the micro pump,
A connection channel provided with an opening whose other end is smaller than the diameter of the outlet channel, and a pulsation of the fluid flowing from the micropump in which the connection channel is drilled And a connection channel pipe having rigidity that can be transmitted to the section.
Here, liquids such as water and physiological saline can be adopted as the fluid.
Moreover, stainless steel, titanium alloy, aluminum alloy, or the like can be employed as the material for the connection channel tube.

According to this invention, when the means for changing the volume of the pump chamber of the micropump is, for example, a piezoelectric element, the fluid flowing from the micropump is pulsated and discharged by the expansion and contraction of the piezoelectric element. Since the connection channel tube with the connection channel drilled is rigid enough to transmit the pulsation of the fluid to the opening, the connection channel tube is deformed when the fluid flows through the connection channel. By doing so, the pulsating fluid is not absorbed, so that the pulsating fluid can be ejected outside the opening.

In the fluid ejecting apparatus according to the aspect of the invention, it is preferable that the micropump includes a fluid resistance element or an inertance increasing element as an outlet channel side fluid control element on the outlet channel side of the connection channel.
Here, the fluid resistance element is a check valve that flows in or out of the fluid, and the inertance increasing element is highly rigid and has a small cross-sectional area for increasing the inertance of the outlet flow path from the pump chamber to the connection flow path. Indicates a pipeline.

Therefore, in the present invention, since the outlet flow channel side control element is provided on the outlet flow channel side of the connection flow channel, reflection of pressure waves in the connection flow channel is performed efficiently, and resonance with the vibration of the piezoelectric element is achieved. Sometimes high pressures can be generated. In particular, the inertance increasing element is more preferable because there is no fear of destruction as in the case of a check valve against a high pressure at the time of resonance in the connecting pipe.

In the present invention, the length of the connection flow path between the outlet flow path side fluid control element and the opening is 10.
It is preferable that it is 0 mm-200 mm.

This fluid ejecting apparatus is used, for example, as a scalpel for a living organ. At this time, in the case of the treatment of the internal organs of the living body, it is required that the opening of the connection flow path reaches the vicinity of the treatment portion inside the living body, but because the connection flow path is set to 100 mm to 200 mm, For example, the length is sufficient for surgery in the liver and cranial nerve regions, and is an appropriate length that does not obstruct the field of view of the operative field. Further, the operator can handle the fluid ejection device accurately. That's it.
In the present invention, although the length of the connection flow path is 100 mm or less or 200 mm or more, a fluid ejecting apparatus having the performance required by the appropriate setting of the micropump can be obtained.
The range of mm to 200 mm is most preferable.

In the fluid ejecting apparatus according to the aspect of the invention, it is preferable that a diameter of the connection flow path is 1 mm to 3 mm and a wall thickness of the connection flow path tube is 0.1 mm to 1 mm.

According to this invention, the maximum diameter of the outer shell of the connection channel tube is 5 mm. This is an appropriate size within the range in which the connection channel tube does not contact the accompanying tissue around the treatment part during the operation of the living organ, similarly to the range of the length of the connection channel described above. Is set in the range of 2 mm to 4 mm.
This means that any combination can be selected in the range of the diameter of the connection flow path from the flow amount of the fluid and the securing of the pulsation described above and the range of the wall thickness selected from the rigidity of the connection flow path pipe. Can do.

As described above, it is preferable that the distal end of the connection flow channel tube is formed thin in consideration of the practicability, but if the angle is acute, the distal end of the connection flow channel tube touches the treatment portion and surrounding accompanying tissue. It is more preferable that the roll is smoothly rounded because there is a risk of damage.

In the present invention, it is preferable that the diameter of the connection channel is larger than the diameter of the inertance increasing element.
According to this invention, the diameter of the connection channel is larger than the diameter of the inertance increasing element, that is, the outlet channel from the pump chamber to the connection channel. That is, a wall that becomes a fluid resistance element of the fluid is formed in the connection flow path by a step formed between the connection portion with the outlet flow channel and the opening at the tip. For this reason, the pressure wave due to the pulsation of the fluid described above is reflected by the step of the opening when it reaches the opening through the connection flow path from the outlet channel of the pump. This pressure wave reflection is repeated between the outlet channel and the pressure amplitude in the connection channel increases, and the pressure pulsation transmitted to the opening increases, so that the fluid ejected from the opening There is an effect that the speed is increased and the incision ability of the living tissue is enhanced.

In the present invention, it is desirable that a nozzle is provided at the opening of the connection channel.
The opening of the connection channel is smaller than the diameter of the outlet channel. At this time, the opening is integrally formed by narrowing the tip of the connection channel pipe in which the connection channel is drilled. However, since it is considered that the tip shape is restricted in manufacturing, it is more desirable to provide a separate nozzle. For example, the nozzle can be shaped to match the treatment section, for example,
Providing the fluid introduction portion with the opening having a reduced diameter also has an effect that the ejected fluid can be accurately and concentratedly ejected to a predetermined portion without being dispersed.

In the driving method of the fluid ejecting apparatus of the present invention, the sound velocity of the fluid in the connection flow path is Q, the length of the connection flow path between the outlet flow side fluid control element and the opening is L, and the pump volume change frequency is When f and n are positive integers, the pump chamber volume is changed so as to satisfy n · 2L = Q / f or 2L / n = Q / f.

As described above, in the connection flow path, walls serving as fluid resistance elements of the fluid are formed at the connection portion of the outlet flow path and the opening at the tip. Further, the fluid pulsates by changing the volume of the pump chamber. As a result, a pressure wave is reciprocally propagated between the fluid resistance elements of the fluid at the end of the connection flow path to generate a high pressure, and the fluid is ejected from the opening at a high speed by this high pressure.
At this time, the relationship between the length L of the connecting flow path, the sound speed Q of the fluid, and the change frequency (pumping element drive frequency) f of the pump chamber volume is n · 2L = Q / f or 2L / n = Q / f. In other words, by setting the resonance frequency of the driving frequency of the piezoelectric element and the period of reciprocal propagation in the fluid connection flow path, the fluid ejected from the opening becomes faster and the incision ability of living tissue is enhanced. There is an effect that it is.

According to another aspect of the invention, there is provided a fluid ejection device driving method including a pump chamber, the micro pump performing a fluid discharge operation by changing the volume of the pump chamber, and one end connected to an outlet flow path of the micro pump. And a connecting flow path provided with an opening at the other end, wherein the fluid is flowed by repetition of a pulsating wave group and a resting portion. Features.

According to the present invention, in the fluid ejecting apparatus as described above, the fluid is caused to flow repeatedly by the pulsating wave group and the resting portion.
Here, the flow due to the repetition of the pulsating wave group and the resting part means that the fluid is caused to flow by intermittent repetition of jetting and stopping, that is, driving of the piezoelectric element (drive time of the pulsating wave group). Since the stop (time of the resting portion) is intermittently performed, incision of the living tissue is performed at the time of driving by the pulsating wave group. As will be described in detail later, when the fluid jet pulsates, the impact pressure of the pulsation increases. Therefore, by increasing the injection pressure at a predetermined cycle, the incision ability can be enhanced as compared with the continuous flow incision.

Also, by adjusting the driving time of the pulsating wave group and the time of the resting part in the repetition of the pulsating wave group and the resting part, the organ parenchyma can be incised. However, it has been obtained from experimental results described later that a tissue having a high Young's modulus can be preserved and bleeding can be reduced.
Furthermore, by providing a time during which the ejection of the fluid is stopped, it is possible to prevent bubbles from remaining in the incised portion of the living tissue, and to prevent the bubbles from obstructing the visual field of the surgical field.

Further, according to the present invention, the time of the pause portion with respect to the driving time of the pulsating wave group is 1 to 5
It is preferable that

Therefore, as described above, it is possible to increase the incision ability by repeating the pulsating wave group and the resting portion, but by setting the above range of the ratio of the driving time of the pulsating wave group and the resting portion time, Experiments to be described later that the incision ability of living tissue is enhanced and the generation of bubbles that obstruct the field of view of the operative field can be reduced by providing the rest time at a certain ratio to the driving time of the pulsating wave group. The result is obtained.

Furthermore, according to this invention, it is preferable that the time of a rest part is 1 msec-10 msec among the repetition of the said pulsating wave group and a rest part.

In incision of a living tissue, etc., fluid is ejected by repetition of a pulsating wave group and a resting portion as described above, so that the incision ability can be enhanced, but the resting portion time is set to 1 msec to 10 ms.
By setting to the range of ec, the interval with the driving time of the pulsating wave group can be set appropriately. From this, at the time of incision of the treatment portion, the bubbles generated when the fluid hits the living tissue can be reduced, and the remaining bubbles can be reduced by providing the above-mentioned appropriate resting time. Therefore, there is an effect that it is possible to prevent further obstruction of the visual field of the operative field.
At this time, as described above, the ratio of the pause time to the drive time of the pulsating wave group is 1 to 1.
More preferably, it is set in the range of 5.

The fluid ejecting apparatus of the present invention includes a pump chamber, and a micropump that performs a fluid discharge operation by changing a volume of the pump chamber is provided with a detachable cover.

According to the present invention, since the cover is attached to the micropump, it is easy for the practitioner to hold the fluid ejection device during the treatment, and it is easy to perform the treatment on the fine part, thereby reducing the fatigue of the practitioner. There is also an effect.
In addition, since this cover is detachable, it can be cleaned by removing the cover from the fluid ejecting device. If used, the operability can be further enhanced.

In the present invention, the cover is preferably formed of a vibration absorbing material or a heat insulating material.
The fluid ejecting apparatus of the present invention is assumed to be operated by grasping with a hand. As previously mentioned,
Since the fluid ejecting apparatus is driven by a piezoelectric element, for example, it is conceivable that the casing constituting the micropump resonates with the vibration of the piezoelectric vibrator and the vibration is transmitted to the hand. Therefore, since the cover is made of a vibration absorbing material, the vibration of the micropump can be absorbed, so that a minute portion can be treated without the vibration being transmitted to the hand.
Here, as the vibration absorbing material, a synthetic resin having a low hardness can be employed in addition to a silicon rubber and a urethane rubber.

Further, since this fluid ejecting apparatus is assumed to be used for a long time and the temperature of the fluid is expected to increase due to the body temperature of the practitioner, the cover is formed of a heat insulating material. There is an effect that the temperature of is difficult to transmit.

In addition to the materials described above being selected, it is more preferable that the cover has a shape that is difficult to slip when it is gripped with a hand, or a surface treatment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 4 are a fluid ejection device and a driving method according to a first embodiment of the present invention, FIG. 5 is a fluid ejection device according to a second embodiment, FIG. 6 is a fluid ejection device according to a third embodiment, and FIGS. The fluid ejection device of Example 4, Table 1, shows the evaluation results of the incision experiment of the living tissue using this fluid ejection device.

1 to 4 show a fluid ejecting apparatus and a driving method thereof according to the first embodiment.
FIG. 1 is a longitudinal sectional view of a fluid ejecting apparatus 10 according to the first embodiment. In FIG. 1, the fluid ejecting apparatus 10 mainly includes a micropump 100, an outlet flow channel connection pipe 300 connected to the micropump 100, and a connection flow channel pipe 200 connected to the outlet flow channel connection pipe 300.

The micropump 100 includes an inlet channel body 1 provided with an inlet channel 122 into which a fluid flows.
20, a pump chamber body 130 having a pump chamber 132 configured by closely fixing a diaphragm 131, and an actuator unit 150 including an actuator 151 that changes the volume of the pump chamber 132.

The inlet channel body 120 has a substantially cylindrical shape in plan view, and is formed by projecting a pipe-shaped inlet connecting pipe 121 having an inlet channel 122 drilled in one side surface. It circulates in the flow path chamber 123. The distal end portion of the inlet channel 122 is connected to an external pipe such as a tube (not shown), and a fluid such as water or physiological saline is supplied. The inlet channel chamber 123 flows into the pump chamber body 130, and a check valve 125 as a fluid resistance element is fixed to the outlet channel side of the pump chamber body 130. The opening of the inlet channel chamber 123 opposite to the check valve 125 is hermetically fixed to the periphery of the inlet channel chamber 123 by a fixing means such as adhesion, welding, or screwing. .

A stepped O-ring box 126 is formed on the outer peripheral portion of the inlet channel body 120 on the check valve side, and a stepped fixing portion 127 into which the pump chamber body 130 is press-fitted outside the O-ring box 126. Is formed.

In the pump chamber body 130, a pump chamber body side outlet channel 301 that flows into the inlet channel chamber 123 is formed on the opposite side of the inlet channel 122 described above. A shallow concave portion is formed on the opposite side of the inlet passage chamber 123 of the pump chamber body 130, and the diaphragm 1 is formed at the periphery of the opening of the concave portion.
31 is fixed. The space formed by the recess and the diaphragm 131 is the pump chamber 13.
2.
Further, the outlet channel connecting pipe 300 is provided with a connecting pipe side outlet channel 302 having the same diameter, which communicates with the pump chamber body side outlet channel 301. The pump chamber body side outlet channel 301 and the connecting pipe side outlet channel 302 are collectively referred to as an outlet channel. Furthermore, this outlet flow path is an inertance increasing element, and thus is an outlet flow path side fluid control element.

In addition, a concave portion 133 having a diameter substantially the same as the step diameter of the fixing portion 127 described above is formed at the joint portion between the inlet channel body 120 and the pump chamber body 130, and a ring-shaped O-ring is formed in the O-ring box 126. 230 is attached. In this state, the fixing portion 127 of the inlet channel body 120 and the concave portion 133 of the pump chamber body 130 are press-fitted and fixed, and the O-ring 230 is pressed to prevent fluid leakage.
The joining of the inlet channel body 120 and the pump chamber body 130 is not limited to press-fitting and is not limited to adhesion or
It can be fixed by screwing.
An actuator unit 150 is attached to the pump chamber body 130 on the diaphragm 131 side.

The actuator unit 150 includes a cylindrical casing 152, a lid member 154 that closes one opening of the casing 152, an actuator 151 whose end is fixed to the inner surface of the lid member 154, a piezoelectric element, 151, an upper base 155 fixed to the other end of 151, and the end opposite to the lid member 154 of the casing 152 presses the diaphragm 131, and the outer periphery thereof is formed in the pump chamber body 130. It is press-fitted into a concave fixing part that is fixed together.

At this time, the upper surface of the upper base 155 in the drawing is in close contact with the diaphragm 131. Although not shown, a hole penetrating from the inside to the outside is provided on the side surface of the casing 152, and a lead wire is provided through the hole, and is also connected to an external control circuit that is not shown. The actuator 151 is a piezoelectric element that expands and contracts in the longitudinal direction. When an AC voltage is applied from an external control circuit, the actuator 151 expands and contracts. When the actuator 151 expands, the diaphragm 131 is pushed and bent to reduce the volume of the pump chamber 132. When contracted, it is pulled back to its original state and the volume of the pump chamber 132 is increased.

Here, the relation of the inertance of the flow path in the micro pump of the present invention will be described. The inertance of the inlet flow path is the inertance of the flow path from the inlet flow path 122 to the check valve 125, while the inertance of the outlet flow path is from the check valve 125 to the pump chamber side outlet flow path 301 and the connection pipe side. It is an inertance of the outlet channel constituted by the outlet channel 302. This 2
Comparing the two inertances, the inertance of the outlet channel is much larger than that of the inlet channel.

The outlet channel connecting pipe 300 is provided with a connecting channel pipe fixing hole 304 into which a later-described connecting channel pipe 200 is press-fitted and fixed. One end of the connection channel pipe 200 is press-fitted into the connection channel pipe fixing hole 304. Further, the outlet channel connecting channel pipe 300 is press-fitted into the outlet channel fixing part 134 with the opposite end of the connecting channel fixing hole 304 protruding from the pump chamber body 130, and the pump chamber body 13.
It is fixed at 0.

The connection channel 201 is provided with a connection channel 201 that circulates with the outlet channel described above. The connection channel tube 200 is formed of a highly rigid metal material. A nozzle 210 having an opening 211 through which fluid is ejected is press-fitted at the tip of the connection flow channel pipe 200.

The nozzle 210 is provided with an opening 211 continuous to the fluid introduction path 212 so that the fluid is not dispersed when the fluid is ejected to one end, and the ejection direction is constant. Also,
The other end portion is provided with a tapered hole 213 that is continuous with the fluid introduction path 212 and has a wider tip side.
Further, the outer peripheral edge of the opening 211 is smoothly rounded by chamfering or arcing.

Next, the connection channel pipe 200 and the connection channel 201 will be described in detail. Connection channel 20
No. 1 has a diameter of 1 to 3 mm, which is larger than the diameter of the outlet channel, and the thickness of the connection channel tube 200 which is the outer shell of the connection channel 201 is set to 0.1 mm to 1 mm. Therefore, the outer diameter of the connection flow path pipe 200 is 5 mm at the maximum.
Moreover, when the distance from the contact part of the end part of the connection flow path pipe 200 and the outlet flow path connection pipe 300 to the inlet of the opening 211 is a connection flow path, and this length is L, L is 100 mm to The range is set to 200 mm.

Next, the driving operation of the micropump 100 of the present invention will be described.
FIG. 2 is a graph showing the relationship between the pressure in the pump chamber 132 and the displacement of the diaphragm 131. This will be described with reference to FIG. First, when the pulsating drive voltage is supplied to the actuator 151, the diaphragm 131 vibrates, and the volume of the pump chamber 132 changes continuously. At this time, the micropump is operated by setting the load pressure of the micropump 100 to 1.5 atm, and the displacement (μm) of the diaphragm 131 when the discharge flow rate of the working fluid is large, the pump chamber 132 indicated by the gauge pressure The waveform of pressure (atmospheric pressure) is shown. In the displacement waveform of the diaphragm 131, the region where the slope of the waveform is positive is a process in which the actuator 151 extends and the volume in the pump chamber 132 decreases. On the other hand, the region where the slope of the waveform is negative is the actuator 15.
1 is a process in which the volume in the pump chamber 132 increases due to contraction.

The pressure in the pump chamber 132 starts to increase when the volume reduction process of the pump chamber 132 starts. Then, for the reason described later, the pressure reaches its maximum value and begins to decrease before the volume reduction process ends. Furthermore, when the volume reduction process of the pump chamber 132 starts, the pressure continues to decrease, and a vacuum state is generated in the pump chamber 132 during the volume reduction process, and the gauge pressure becomes a constant value of −1 atm.

A graph of the relationship between the flow rate waveforms in the inlet channel and the outlet channel at this time is shown in FIG. The flow rate that flows in the forward direction (load direction) when the micropump 100 is operated is the positive direction on the graph.

The flow rate of the outlet channel starts to increase when the pressure in the pump chamber 132 rises and exceeds the load pressure. Then, the working fluid in the pump chamber 132 starts to flow out of the outlet channel, and the pressure in the pump chamber 132 starts to decrease at a point where the outflow amount exceeds the volume reduction amount of the pump chamber 132 due to the displacement of the diaphragm 131. This is due to the inertial effect that kinetic energy is stored in the fluid in the outlet channel due to the large inertance of the outlet channel. When the pressure in the pump chamber 132 decreases and falls below the load pressure, the outlet flow rate starts to decrease. These flow rate change rates are substantially equal to a value obtained by dividing the pressure difference between the pressure in the pump chamber 132 and the load pressure by the inertance value of the outlet channel.

On the other hand, in the inlet flow path, when the pressure in the pump chamber 132 decreases than the pressure in the inlet flow path,
The check valve 125 opens due to the pressure difference, and the flow rate begins to increase. Moreover, when the pressure in the pump chamber 132 rises and increases above the atmospheric pressure, it begins to decrease. These flow rate change rates are equal to the check valve 125.
In the same manner as described above, the period during which is opened is substantially equal to a value obtained by dividing the pressure difference between the pressure in the pump chamber 132 and the pressure on the upstream side of the inlet channel by the inertance value of the inlet channel. And
Backflow is prevented by the check effect of the check valve 125.

Next, the ejection of the fluid opening will be described.
First, the fluid that has flowed out of the outlet channel as a pulsation to the connection channel 201 due to the volume change of the pump chamber 132 generates a high pressure on the side of the connection channel side outlet channel 302 in the connection channel 201. This is because the opening 211 has a very small diameter. The generated high pressure is applied to the connection channel 201.
The fluid propagates through the inside at the sound velocity of the fluid in the connection channel 201, and the fluid is ejected from the opening 211 at a high speed by this high pressure. A part of the pressure wave is reflected by the wall surface of the fluid introduction path 212 and propagates again to the outlet channel side.

The pressure wave propagating to the outlet channel side is reflected again by the wall of the step portion formed on the joint surface between the connection channel 201 and the connection channel side outlet channel 302. At this time, by synchronizing the discharge of the fluid from the outlet channel into the connection channel 201, the maximum pressure of the pressure wave can be further increased,
From the opening 211, more powerful injection becomes possible.

Therefore, the sound velocity of the fluid in the connection channel 201 is Q, the length of the connection channel between the outlet channel side fluid control element and the opening is L, the change frequency of the pump chamber volume is f, and n is a positive integer. When
When 2L = Q / f is satisfied, the fluid can be ejected most efficiently. This condition is
That is, the pressure wave of the fluid is in resonance with the change frequency of the pump volume.
Furthermore, even under the condition of n · 2L = Q / f or 2L / n = Q / f, reflection of pressure waves by the wall of the stepped portion formed on the joint surface with the connection pipe side outlet flow path 302, and from the outlet flow path Since the discharge of the fluid into the connection flow path 201 is synchronized, efficient injection becomes possible.
Therefore, the connection flow path pipe 200 is provided with a rigidity that does not cause deformation or resonance due to the pressure wave.
Further, the sound velocity of the fluid in the connection channel 201 referred to here is a sound velocity that takes into account the influence of the rigidity of the connection channel 201.

Then, the result of having measured the ejection state of the fluid in the fluid ejection apparatus 10 of the present Example 1 is demonstrated.
FIG. 4 is a graph showing the result of measuring the stagnation pressure waveform of the ejected fluid with the driving frequency of the actuator 151 made of a piezoelectric element and the pressure sensor facing the opening 211.
In FIG. 4, the upper graph is a drive waveform of the actuator (piezoelectric element) 151, and a period in which a pulsating waveform on the left side in the figure is shown indicates the drive time of the pulsating wave group.
In the figure, the lower graph shows the stagnation pressure waveform of the fluid in the opening 211.
The horizontal axis indicates the elapsed time (unit, second).

Next, the requirements of each part of the fluid ejection device 10 will be described. An outlet flow path having a length of 150 mm for the connection flow path L, a diameter of the opening 211 of 0.2 mm, an effective diameter of the diaphragm 131 of 6 mm, a diameter of 0.75 mm as an inertance increasing element, and a length of 12 mm was set.
The driving frequency of the actuator 151 is 2.2 kHz in FIG. 4A and 3 in FIG.
7 kHz, FIG. 4C shows 5 kHz. The drive voltage of the actuator 151 is 100 V, and 6 pulses are output during the ON period.

In FIG. 4A, the stagnation pressure due to fluid injection is 2 atm or less, but is stable.
In FIG. 4B, the maximum value of the stagnation pressure exceeds 2 atmospheres, but becomes unstable thereafter.
FIG. 5C shows the highest stagnation pressure. The stagnation pressure rises once every two drive cycles because the inertance increasing element is used as the outlet flow side fluid control element. The inertance increasing element causes the flow in the outlet flow to be driven by the driving voltage. It shows that it continues for longer than one cycle. This indicates that the pump is efficiently discharging the fluid, and since this 5 kHz corresponds to the resonance frequency of the fluid in the connecting flow path, the stagnation pressure rises due to a synergistic effect. Since the incision ability of the living tissue has a correlation with the stagnation pressure, it is preferable that the fluid ejecting apparatus of this requirement is driven at 5 kHz.

Table 1 shows the results of an experiment in which the liver of the vagina was actually incised under the conditions described above.
Table 1 shows the evaluation results when the incision state of the liver tissue, the amount of bleeding, and the generation of bubbles at the time of incision were tested while changing the driving time of the pulsating wave group of the actuator 151 and the time of the resting portion.
The driving frequency of the actuator 151 was 5 kHz and 100 V.
The evaluation results are indicated such that × is not possible, Δ is an acceptable range, ○ is good, and ◎ is the best.

From the experimental results shown in Table 1, the range in which the time of the resting portion (the time of the resting portion / the driving time of the pulsating wave group) with respect to the driving time of the pulsating wave group is in the range of 1 to 5 (experiment numbers 3 to 6) is acceptable In addition, a range in which the time of the resting portion is 1 msec to 10 msec is acceptable (experiment numbers 3 to 6).
).
There is no data for the rest period of 1 msec, but there is data that cannot be evaluated when experiment number 7 is 0.4 msec, and the best evaluation result is obtained when experiment number 6 is 2 msec.
It was estimated that the range was acceptable up to msec.

Therefore, in the first embodiment, the fluid ejecting apparatus 10 includes the pump chamber 132 of the micropump 100.
The means for changing the volume of the micropump 100 is a piezoelectric element actuator 151.
The fluid flows in a pulsating manner, but since the connecting flow channel pipe 200 is highly rigid, the pressure wave due to the pulsation propagates to the opening, the incision ability is high, and the ejection of the fluid due to the pulsation in which bubbles are not easily generated Is possible.

Further, the micropump 100 is provided with an outlet channel formed of a pump chamber body side outlet channel 301 and an outlet channel side outlet channel 302 as an inertance increasing element as an outlet channel side fluid control element on the outlet channel side. Therefore, high pressure can be generated by the pump.
Further, since the connection pipe side outlet flow channel 302 and the opening 211 are formed with a stepped wall in the fluid flow direction at the connection portion with the connection flow channel 201, the pressure wave is generated in the connection flow channel 201. It is reflected more efficiently between the walls of the, and the pressure can be increased by resonance at the appropriate drive frequency. In addition, the wall on the outlet channel side has an effect that there is no fear of being broken because the structural strength is higher than that of the check valve.

This fluid ejecting apparatus 10 is used as a scalpel for a living organ. At this time, when performing tissue incision of the internal organ of the living body, it is required that the opening 211 reaches the vicinity of the treatment portion inside the living body, but the connection channel 201 (L in the figure) is set to 100 mm to 200 mm. Therefore, for example, it is long enough to perform surgery on the liver and cranial nerve regions and incision of other organs, etc., and has an appropriate length that does not obstruct the field of view of the operative field. The length is such that the practitioner can handle the fluid ejecting apparatus 10 accurately.
In the present invention, although the length of the connection flow path is 100 mm or less or 200 mm or more, a fluid ejecting apparatus having the performance required by the appropriate setting of the micropump can be obtained.
The range of mm to 200 mm is most preferable.

In the fluid ejecting apparatus 10 according to the first embodiment, the diameter of the connection channel 201 is 1 mm to 3 mm, and the thickness of the outer shell of the connection channel pipe 200 is set in the range of 0.1 mm to 1 mm. Road pipe 2
The outer shell diameter of 00 is a maximum of 5 mm. This is an appropriate thickness in a range where the connection flow channel tube 201 does not contact the periphery of the treatment portion during the operation of the organ, similar to the range of the length of the connection flow channel 201 described above, but preferably 2 mm. It is set in a range of ˜4 mm.

Moreover, in Example 1, since the nozzle 210 is provided in the opening part of the connection flow path pipe | tube 200, for example, the shape according to the treatment part can be selected freely, for example, the diameter is reduced. By providing the fluid introduction part 212 in the opening 211 that is present, there is also an effect that the concentrated flow can be accurately ejected to a predetermined part without dispersion of the ejected fluid.
The nozzle 210 is press-fitted into the connection flow channel pipe 200. However, if a screw is screwed into the nozzle 210 and the connection flow channel pipe 200 and screwed and fixed, an appropriate nozzle is selected depending on the site of the treatment portion. Can be easily used.

Furthermore, in Example 1, the length L of the connection flow path, the sound velocity Q of the fluid, the pump volume change frequency (
Since the relationship with the driving frequency (f) of the piezoelectric element is n · 2L = Q / f or 2L / n = Q / f, the reflection of the pressure wave of the fluid is resonant with the driving frequency of the actuator 151 (piezoelectric element). Therefore, the pressure of the fluid in the connection flow path becomes higher and the fluid is efficiently ejected at a high speed, so that there is an effect that the cutting ability of the living tissue is enhanced.

Further, in the fluid ejection device 10 according to the first embodiment, the fluid is caused to flow by repetition of the pulsating wave group and the resting portion. As described above, since the incision ability is increased by the stagnation pressure due to the pulsation during the driving by the pulsating wave group and the repetition of the resting portion, the incision ability can be enhanced as compared with the continuous flow incision. Moreover, since the incision by pulsation reduces the amount of fluid, there is an effect that the generation of bubbles due to the fluid accumulated in the surgical field is also reduced.

Moreover, the time of the rest part with respect to the driving time of the pulsating wave group is 1 to 5, and the time of the rest part is 1 msec.
Since it is set in the range of 10 msec to 10 msec, the incision ability of the ejected fluid can be enhanced, but the interval with the driving time of the pulsating wave group can be appropriately set. From this, at the time of incision of the treatment portion, the bubbles generated when the fluid hits the living tissue can be further reduced, and the remaining bubbles can be reduced by providing a time for the resting portion. Therefore, it is possible to prevent the problem that the bubbles obstruct the visual field of the operative field.

FIG. 5 shows a fluid ejection device 10 according to a second embodiment of the present invention. The second embodiment is characterized in that the outlet flow channel pipe 300, the connection flow path pipe 200, and the nozzle 210 shown in the first embodiment are integrally formed, and the structure of the micro pump 100 and the driving of the fluid ejecting apparatus other than that are characterized. The method is the same as that of Example 1 (see FIGS. 1 to 4), and almost the same evaluation is obtained for the experimental results. Therefore, only the differences will be described. In addition, the same code | symbol is provided to the functional part same as Example 1 (refer FIG. 1).

FIG. 5 shows a longitudinal section of the fluid ejection device 10 of the second embodiment. In FIG.
0, one end is press-fitted into a connection flow channel pipe fixing portion 134 protruding from the side surface of the pump chamber body 130, and the outlet flow channel 301 and the pump chamber 132 are circulated. Opening 2 of connecting flow channel pipe 200
11, the outlet channel 301 is formed up to a position where the diameter of the channel is changed, and the connecting channel 201 is formed from the outlet channel 211 to the position.

The diameters of the connection channel 201 and the outlet channel 301 are large on the connection channel side. The distal end of the connection flow channel pipe 200 has a narrowed shape and an opening 21 having a fluid introduction part 212 on the fluid inlet side.
1 is provided. Note that the outside of the opening is gently rounded.
Here, the connection channel is from the boundary with the outlet channel 301 to the fluid inlet of the opening 211, and the length L is set in the range of 100 mm to 200 mm.
The connection flow channel pipe 200 has the same rigidity as that of the first embodiment.

The diameter of the connection channel 201 is 1 mm to 3 mm, and the thickness of the outer shell of the connection channel pipe 200 is 0.
. As in Example 1, the relationship between the length L of the connection flow path, the sound velocity Q of the fluid, and the pump volume change frequency (piezoelectric element drive frequency) f is set to n · 2L = The pump volume changing frequency f is set so that Q / f or 2L / n = Q / f.

Therefore, the second embodiment differs from the first embodiment in that the outlet channel pipe 300, the connection channel pipe 200, and the nozzle 210 shown in the first embodiment are integrally formed. The same effect as 1 can be obtained.
Further, the connection channel pipe 200 can form the opening 211 by a processing means such as narrowing the tip of a metal pipe, so that the structure is simple and the cost can be reduced.

FIG. 6 shows a fluid ejecting apparatus according to Embodiment 3 of the present invention. Example 3 is a structure in which check valves as fluid resistance elements are provided on the inlet channel side and the outlet channel side, and provides a fluid ejecting apparatus having another structure without changing the technical idea of Example 1 and Example 2. Is. In addition, Example 1 (FIG. 1,
The same reference numerals are given to the same functional portions as those of the second embodiment (see FIG. 5).
FIG. 6 is a longitudinal sectional view of the fluid ejecting apparatus according to the third embodiment. In FIG. 6, the fluid ejection device 10
Is composed of a pump chamber body 130 including an inlet channel 122, a connection channel 201 and a pump chamber 132, and an actuator unit 150 including an actuator 151 and a casing 152 to which the actuator 151 is fixed.

An inlet channel check valve 141 is provided on the pump chamber 132 side of the connection portion of the inlet channel 122 with the pump chamber 132, and the inlet channel check valve 141 is opened to the pump chamber 132 side. .
The other end of the inlet channel 122 is connected to a tube 143 that circulates in a tank (not shown). The connection flow path 122 is bent at about 90 degrees in the drawing just before flowing into the pump chamber 132, but this angle and direction are not particularly limited, and the curvature is within a range that does not increase the fluid resistance. If so, the performance is not affected.
A connection flow path check valve 142 is also provided on the connection flow path 201 side.

The connection flow path check valve 142 is provided at substantially the same distance as the inlet flow path check valve 141 with respect to the actuator 151. This connection flow path check valve 142 is opened to the connection flow path 201 side. The connection flow path 201 is pierced by a pipe-shaped connection flow path pipe 200 protruding from the pump chamber body 130, and a nozzle 210 is press-fitted at the tip. In the third embodiment, the first embodiment described above.
The connection channel pipe 200, the outlet channel connection pipe 300, and the pump chamber body 130 shown in FIG. 1 are integrally configured, and the functions thereof are the same as those of the first embodiment.

A diaphragm 131 is fixed in close contact with the actuator unit 150 side of the pump chamber body 130, and a space constituted by the diaphragm 131 and the pump chamber body 130 is a pump chamber 1.
32.

In the actuator unit 150, one end face of the actuator 151 made of a piezoelectric element is fixed to the inner end face of the casing 152 that is open at one end, and the opening periphery of the casing 152 is fixed to the diaphragm 131. At this time, the other end surface of the actuator 151 is brought into close contact with the diaphragm 131.

Here, the actuator unit 150 and the pump chamber body 130 (excluding the connection flow path 201)
Is called a micropump. The driving operation of the micropump is the same as that shown in the first embodiment, except that the two check valves 141 and 142 are provided.
The operation of 1,142 will be described.

When the actuator (piezoelectric element) 151 contracts, the volume of the pump chamber 132 is increased,
The inlet flow path check valve 141 is opened and the fluid flows into the pump chamber 132, and the connection flow path check valve 14.
2 is sealed and the outflow of fluid stops. Further, when the actuator 151 extends, the volume of the pump chamber body 132 decreases, the inlet flow path check valve 141 is sealed, the connection flow path check valve 142 is opened, and the fluid flows out.

Here, the requirements of the connection channel 201 and the connection channel pipe 200 will be described.
Connection channel check valve 142 as an outlet channel side fluid control element and opening 211 of nozzle 210
The length L of the connection channel between the inlet side of the tube and the diameter of the connection channel 201 is 1 mm to 3 mm, and the thickness of the outer shell of the connection channel tube 200 is in the range of 0.1 mm to 1 mm. Set with.

Further, as a driving method of the fluid ejecting apparatus 10, the sound velocity of the fluid in the connection flow path is Q, the length of the connection flow path is L, the pump chamber volume changing frequency is f, and n is a positive integer. N
Change the pump chamber volume so that 2L = Q / f or 2L / n = Q / f.

Similarly to the first embodiment, the fluid ejection device 10 according to the third embodiment is caused to flow by repeating the pulsating wave group and the resting portion, but the resting portion time with respect to the driving time of the pulsating wave group is 1 to 5, and the pulsation The time of the repetitive rest part of the wave group and the rest part is driven in a combination in the range of 1 msec to 10 msec.

Accordingly, in the third embodiment, two check valves are provided as fluid resistance elements. However, since the requirements related to the fluid ejection are set to be the same as those in the first embodiment, the obtained effects are equivalent.
It should be noted that a general micropump is often provided with check valves on the inflow side and the outflow side of the pump chamber as in the third embodiment, but such a micropump can also satisfy the above-described requirements of the present embodiment. In this case, the same effect can be obtained.

7 to 9 show a fluid ejecting apparatus 11 with a cover according to a fourth embodiment of the present invention. The fourth embodiment is characterized in that the fluid ejecting apparatus shown in the first to third embodiments includes a cover that is easy to operate by grasping with a hand. 7 to 9 show the fluid ejecting apparatus described in the first and second embodiments as an example, it goes without saying that the fluid ejecting apparatus of the third embodiment can be applied.
7 is a longitudinal sectional view of the fluid ejecting apparatus 11 with a cover according to the fourth embodiment, FIG. 8 is a longitudinal sectional view of the cover 160, and FIG. 9 is a plan view of the fluid ejecting apparatus 11 with a cover shown in FIG. . 7 and 8, the fluid ejecting apparatus 10 covers the periphery of a part of the tube 143 connected to the micropump 100, the connection flow channel pipe 200, and the inlet connection pipe 121 by the cover 160.

In FIG. 8, the cover 160 is divided into an upper cover 165 and a lower cover 166 at the position indicated by AA. In a state where the upper cover 165 and the lower cover 166 are combined, a space 161 into which the main body portion of the micropump 100 enters and a space 162 into which the outlet channel tube 300 enters are configured.
As shown in FIG. 7, the fluid ejecting apparatus 10 is covered with a cover 160, but the micropump 100 is provided with a space so as not to contact the cover 160.

The cover 160 squeezes and fixes the tube 143 and the connection channel pipe 200 with the covers 165 and 166, but the internal space of the cover 160 is sealed from the outside air. Therefore,
The fixing portion 167 on the tube 143 side and the fixing portion 168 on the connection flow channel pipe 200 side are holes that have the same or smaller diameter as the tube outer diameter and the outer diameter of the connection flow channel tube 200, respectively, and are brought into a pressure contact state.
In particular, the sealing performance is enhanced by inserting a pipe-shaped seal member 169 into the fixing portion 168 on the connection flow channel side.

In FIG. 9, the upper cover 165 and the lower cover 166 (not shown) are screwed up and down by screws 170 in the vicinity of the tube 143 and in the vicinity of the connection flow channel pipe 200. On this occasion,
A countersunk hole 171 is provided on the screw head of the screw 170 so as to be buried in the cover.
In addition, as a material of the cover 160, there is a rigidity that does not deform even if it is gripped, and a material that has high vibration absorption and high heat insulation is selected, but silicon rubber, urethane rubber,
Other rigid resins having a low hardness can be used. However, it has such rigidity that it does not deform when the cover 160 is gripped.

The fluid ejecting apparatus of the present invention is operated by grasping with a hand. Therefore, in the fourth embodiment, as described above, since the fluid ejecting apparatus 10 is driven by the piezoelectric element, the casing 152 and the like constituting the micropump 100 resonate with the vibration of the piezoelectric element, and the vibration is manually performed. It is thought that it is transmitted to. Therefore, since the cover 160 is made of a vibration absorbing material, the vibration of the micropump 100 can be absorbed, so that the vibration is not transmitted to the hand and it is easy to perform a treatment on a fine part, and the operator's fatigue is reduced. There is also an effect.

In addition, since this cover is detachable, it can be cleaned by removing the cover from the fluid ejecting device. If used, the operability can be further enhanced.

Further, the fluid ejecting apparatus 10 is assumed to be used for a long time, and it is considered that the temperature of the fluid rises due to the body temperature of the practitioner. Therefore, since the cover is formed of a heat insulating material, There is an effect that the temperature is not easily transmitted.
Further, since the fluid ejecting apparatus 10 is covered with the cover 160, it is possible to prevent the ejected fluid, blood, and the like from adhering to the micropump 100 when the living tissue is incised.

In addition, this invention is not limited to the above-mentioned Example, The deformation | transformation in the range which can achieve the objective of this invention, improvement, etc. are included in this invention.
For example, in the above-described embodiment, the fluid ejecting apparatus has been described by taking the incision of a living tissue as an example.
In addition, it can also be applied to crushing stones, introducing liquid into living cells, and removing intravascular emboli.
Furthermore, the present invention can be applied to a power device or a cooling device using the above-described jet flow as a power source even outside the medical field.

Therefore, in the above-described Examples 1 to 4, it is possible to enhance the incision ability of living tissue, incision can be made only on the lesioned tissue part while preserving vascular tissue such as blood vessels, etc. It is possible to provide a fluid ejecting apparatus that reduces the field of view of the surgical field and a driving method thereof.

1 is a longitudinal sectional view of a fluid ejection device according to Embodiment 1 of the present invention. The graph which shows the relationship between the pressure in the pump chamber which concerns on Example 1 of this invention, and the displacement of a diaphragm. The graph which shows the relationship of the waveform of the flow volume in the inlet channel which concerns on Example 1 of this invention, and an outlet channel. The graph which shows the relationship between the drive frequency of the actuator which concerns on Example 1 of this invention, and the stagnation pressure waveform of the injected fluid. The longitudinal cross-sectional view of the fluid injection apparatus which concerns on Example 2 of this invention. FIG. 6 is a longitudinal sectional view of a fluid ejecting apparatus according to a third embodiment of the invention. FIG. 9 is a longitudinal sectional view of a fluid ejecting apparatus according to a fourth embodiment of the invention. The longitudinal cross-sectional view of the cover of the fluid injection apparatus which concerns on Example 4 of this invention. FIG. 9 is a plan view of a fluid ejection device according to a fourth embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Fluid injection apparatus, 100 ... Micro pump, 132 ... Pump chamber, 160 ... Cover,
DESCRIPTION OF SYMBOLS 200 ... Connection flow pipe, 201 ... Connection flow path, 211 ... Opening part, 301 ... Pump chamber body side exit flow path, 302 ... Connection flow side exit flow path.

Claims (12)

A micropump comprising a pump chamber, and performing a fluid discharge operation by changing the volume of the pump chamber;
One end is connected to the outlet channel of the micropump, and the other end is provided with an opening that is smaller than the diameter of the outlet channel.
The connection flow path pipe having the rigidity capable of transmitting the pulsation of the fluid flowing from the micropump to the opening, the connection flow path being perforated;
Is provided. The fluid ejection device according to claim 1,
The fluid ejection device according to claim 1, wherein the micropump includes a fluid resistance element or an inertance increasing element as an outlet channel side fluid control element on the outlet channel side of the connection channel. The fluid ejection device according to claim 1 or 2,
The length of the connection flow path between the outlet flow path side fluid control element and the opening is 100 mm to 20
A fluid ejecting apparatus characterized by being 0 mm. The fluid ejection device according to any one of claims 1 to 3,
The diameter of the connection channel is 1 mm to 3 mm, and the thickness of the outer shell of the connection channel pipe is 0.1 mm to
A fluid ejecting apparatus having a diameter of 1 mm. The fluid ejection device according to any one of claims 1 to 4,
The fluid ejecting apparatus according to claim 1, wherein a diameter of the connection channel is larger than a diameter of the inertance increasing element. The fluid ejection device according to any one of claims 1 to 5,
A fluid ejecting apparatus comprising a nozzle at a tip of the connection flow path. The sound velocity of the fluid in the connection flow path is Q, the length of the connection flow path between the outlet flow side fluid control element and the opening is L, the change frequency of the pump chamber volume is f, and n is a positive integer. When
A method of driving a fluid ejecting apparatus, wherein the pump chamber volume is changed to satisfy n · 2L = Q / f or 2L / n = Q / f. A micropump having a pump chamber and changing the volume of the pump chamber to discharge fluid; one end of the micropump is connected to an outlet flow path of the micropump, and an opening is provided at the other end A connection flow path, and a fluid ejection device driving method comprising:
A fluid ejection apparatus driving method, wherein the fluid is caused to flow by repetition of a pulsating wave group and a resting portion. The driving method of the fluid ejection device according to claim 8,
The fluid ejecting apparatus driving method according to claim 1, wherein a time of the pause portion is 1 to 5 with respect to a driving time of the pulsating wave group. The driving method of the fluid ejection device according to claim 8 or 9,
The method of driving a fluid ejecting apparatus, wherein a time of the pause portion is 1 msec to 10 msec. A fluid ejecting apparatus, comprising: a pump chamber, wherein a detachable cover is attached to a micro pump that performs a fluid discharge operation by changing a volume of the pump chamber. The fluid ejection device according to claim 11, wherein
The fluid ejecting apparatus, wherein the cover is formed of a vibration absorbing material or a heat insulating material.

Images