JP2014013040A - Fluid jetting device, fluid jetting surgical instrument and fluid jetting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid jetting device, a fluid jetting surgical instrument and a fluid jetting method which enable a pressure of fluid jetted from a nozzle can be appropriately adjusted in accordance with a distance between the nozzle and a fluid jetting object.SOLUTION: A fluid jetting device 1 comprises: volume change means 401 for changing a volume of a fluid chamber 501; and a pulsation generation section 100 having an inlet flow passage 503 and an outlet flow passage 511 which communicate with the fluid chamber 501. The fluid jetting device 1 further comprises: flow passage pipe 200 having a connection flow passage 201 communicating with the outlet flow passage 511 and a fluid jetting port 212; fluid supply means 20 for supplying fluid to the inlet flow passage 503; control means 30 for controlling the volume change means 401; and distance detection means 40 for detecting a distance between the fluid jetting port 212 and a fluid jetting object. The control means 30 controls the volume change means 401 in accordance with the distance detected by the distance detection means 40.

Description

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

Conventionally, as this type of technology, for example, there is a fluid ejecting apparatus that ejects high-pressure fluid from a nozzle provided at the tip of the handpiece by supplying pressurized fluid to the handpiece from a pressure pump (patent) Reference 1). Further, in this fluid ejecting apparatus, a suction tube is disposed in the nozzle, and the fluid ejected to the ejection target is sucked by driving a suction pump connected to the suction tube.
And in the said prior art, the measurement part which can measure the distance of a nozzle and the surface of a fluid injection target object is provided, and it injects from a nozzle by adjusting a pressurization pump according to the distance which the measurement part measured. Adjust the fluid pressure.
Here, generally, the pressurizing pump used in the fluid ejecting apparatus has a large configuration with respect to the handpiece. Therefore, in the fluid ejecting apparatus, the pressurizing pump is disposed away from the handpiece, and the pressurizing pump and the handpiece are connected by a tube or the like.

Japanese Patent Laid-Open No. 5-76540

In the prior art, in order to adjust the pressurization pump that is arranged apart from the handpiece, and because the fluid ejected from the nozzle is a continuous flow, depending on the distance between the nozzle and the fluid ejection object, It has been difficult to properly adjust the pressure of the fluid ejected from the nozzle.
The present invention has been made in view of the above prior art, and is a fluid ejecting apparatus capable of appropriately adjusting the pressure of fluid ejected from a nozzle according to the distance between the nozzle and a fluid ejecting object. It is an object of the present invention to provide a fluid ejection surgical instrument and a fluid ejection method.

  In order to achieve the above object, a fluid ejecting apparatus according to a first invention includes a fluid chamber into which a fluid flows, volume changing means for changing the volume of the fluid chamber, an inlet channel and an outlet flow communicating with the fluid chamber. A pulsation generator having a channel, a channel tube having a connection channel whose one end communicates with the outlet channel and the other end communicates with the fluid ejection port, and fluid supply means for supplying fluid to the inlet channel And a control means for controlling the change of the volume of the fluid chamber by the volume changing means, and a distance detecting means for detecting the distance between the fluid ejection port and the fluid ejection object, and the control means is detected by the distance detecting means. The change of the volume of the fluid chamber by the volume changing means is controlled according to the distance.

In the fluid ejection device according to the first aspect of the present invention, the pulsation generating unit communicating with the flow path pipe is controlled according to the distance between the fluid ejection port and the fluid ejection object. Depending on the distance, it is possible to appropriately adjust the pressure of the fluid ejected from the fluid ejection port.
For example, in the fluid ejection device according to the first aspect of the invention, the pulsation communicated with the flow path tube when adjusting the pressure of the fluid ejected from the fluid ejection port according to the distance between the fluid ejection port and the fluid ejection object. Control the generator. Thereby, compared with the case where the fluid supply means (pump) is controlled, the pressure of the fluid ejected from the fluid ejection port is adjusted with high responsiveness according to the distance between the fluid ejection port and the fluid ejection object. It becomes possible.

Moreover, since the pulsation generation | occurrence | production part connected to a flow-path pipe is controlled when adjusting the pressure of the fluid injected, generation | occurrence | production of a water hammer phenomenon can be suppressed.
In the fluid ejecting apparatus according to the first aspect of the present invention, the fluid ejected from the fluid ejection port becomes a pulsating flow by providing the pulsation generating unit. Here, when the pulsating flow is ejected from the fluid ejection port, the flow rate of the fluid to be ejected can be reduced as compared with the case of ejecting the continuous flow. Therefore, the change in the flow rate of the fluid to be ejected when the pressure of the fluid ejected from the fluid ejection port is adjusted is smaller than that in the case of injecting a continuous flow. Thereby, when adjusting the pressure of the fluid injected from a flow-path pipe | tube according to the distance of a fluid injection opening and a fluid injection target, adjustment of a suction pump becomes unnecessary.

  Here, for example, a fluid chamber 501 described later corresponds to the fluid chamber. For example, a piezoelectric element 401 described later corresponds to the volume changing unit. For example, an inlet channel 503 described later corresponds to the inlet channel. For example, an outlet channel 511 described later corresponds to the outlet channel. As the pulsation generation unit, for example, a pulsation generation unit 100 described later corresponds. For example, a connection channel 201 described later corresponds to the connection channel. For example, a fluid ejection opening 212 described later corresponds to the fluid ejection port. An example of the flow path tube is a connection flow path tube 200 described later. For example, a pump 20 described later corresponds to the fluid supply unit. For example, the control means 30 described later corresponds to the control means. As the distance detection means, for example, the distance detection means 40 described later corresponds.

  Further, the fluid ejection device according to the second invention is the fluid ejection device according to the first invention, wherein the distance detection means transmits the light emitted from the light source and the light emitted from the light source to the fluid ejection port. A light transmission unit that guides the reflected light that is guided by the light and emitted toward the fluid ejection target, receives the reflected light reflected by the fluid ejection target and is reflected by the fluid ejection target And a light receiving unit that receives the reflected light guided by the light transmission unit and outputs a signal corresponding to the received light, and a distance between the fluid ejection port and the fluid ejection target object based on the signal output by the light receiving unit And a signal processing unit for calculating.

In the fluid ejecting apparatus according to the second aspect of the invention, the light ejected from the light source unit is guided to the fluid ejecting port, and the light transmitting unit guides the reflected light reflected from the fluid ejecting object. When exchanging the distance detection means in accordance with the exchange of the path pipe, only the optical transmission unit needs to be exchanged, so that the cost can be reduced.
Here, as the light source unit, for example, a light source unit 41 described later corresponds. As the optical transmission unit, for example, an optical transmission unit 42 described later corresponds. For example, the light receiving unit 43 described later corresponds to the light receiving unit. For example, the signal processing unit 44 described later corresponds to the signal processing unit.

The fluid ejection device according to the third invention is the fluid ejection device according to the first or second invention, wherein the volume changing means is a piezoelectric element, and the control means is in accordance with the distance detected by the distance detection means. The voltage applied to the piezoelectric element is controlled.
In the fluid ejecting apparatus according to the third aspect of the invention, the voltage applied to the piezoelectric element is controlled according to the distance between the fluid ejecting port and the fluid ejecting object, so that the adjustment of the pressure of the fluid ejected from the fluid ejecting port is simple. It becomes.
Here, for example, a piezoelectric element 401 described later corresponds to the piezoelectric element.

The fluid ejection device according to a fourth aspect of the present invention is the fluid ejection device according to any one of the first to third aspects, wherein the control means increases the fluid ejection port as the distance detected by the distance detection means increases. The change of the volume of the fluid chamber by the volume changing means is controlled so that the pressure of the fluid ejected from is increased.
In the fluid ejection device according to the fourth aspect of the present invention, it is possible to more appropriately adjust the pressure of the fluid ejected from the fluid ejection port according to the distance between the fluid ejection port and the fluid ejection object. For example, even when the distance between the fluid ejection port and the fluid ejection object is changed, the pressure of the ejected fluid in the fluid ejection object can be controlled to be constant. In particular, when the fluid ejecting apparatus is applied to a fluid ejecting surgical instrument for incising or excising a surgical target site, even if the distance between the fluid ejection port and the surgical target site is changed, a constant incision or excision with respect to the surgical target site is performed. Ability can be maintained.

The fluid ejection surgical instrument according to the fifth aspect of the present invention includes a fluid chamber into which fluid flows, volume changing means for changing the volume of the fluid chamber, and an inlet channel and an outlet channel communicating with the fluid chamber. A pulsation generating section; a channel pipe having a connection channel whose one end communicates with the outlet channel and the other end communicates with a fluid ejection port; fluid supply means for supplying fluid to the inlet channel; and volume changing means Control means for controlling the change of the volume of the fluid chamber by the distance detection means for detecting the distance between the fluid ejection port and the surgical target site, the control means according to the distance detected by the distance detection means, The change of the volume of the fluid chamber by the volume changing means is controlled, and the volume changing means changes the volume of the fluid chamber so that the surgical target site is incised or excised by the fluid ejected from the fluid ejection port.
In the fluid ejection surgical instrument according to the fifth invention, the fluid ejection port, the fluid ejection object, and the fluid ejection object are controlled in accordance with the distance between the fluid ejection port and the fluid ejection object, in order to control the pulsation generating unit communicating with the flow path pipe The pressure of the fluid ejected from the fluid ejection port can be appropriately adjusted according to the distance.

In the fluid ejection method according to the sixth aspect of the present invention, the fluid is supplied from the fluid ejection port communicating with the connection flow path by supplying fluid to the fluid chamber communicating with the connection flow path and changing the volume of the fluid chamber. The fluid is ejected, the distance between the fluid ejection port and the fluid ejection object is detected, and the change of the volume of the fluid chamber is controlled according to the detected distance.
In the fluid ejection method according to the sixth aspect of the present invention, the pulsation generation unit communicating with the flow path pipe is controlled according to the distance between the fluid ejection port and the fluid ejection object, Depending on the distance, it is possible to appropriately adjust the pressure of the fluid ejected from the fluid ejection port.

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

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

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

Note that when performing an operation using the water pulse knife 1, the part grasped by the operator is the pulsation generator 100 or the connecting flow channel tube 200. Therefore, it is preferable that the connection tube 25 up to the pulsation generator 100 be as flexible as possible. For this purpose, it is preferable that the pressure is reduced within a range in which fluid can be sent to the pulsation generator 100 with a flexible and thin tube.
The pulsation generator 100 includes a fluid chamber 501 (see FIG. 2) and a volume changing unit for the fluid chamber 501. In the present embodiment, the piezoelectric element 401 is used as the volume changing means of the fluid chamber 501.

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

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

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

In addition, although the shape of the fluid chamber 501 is a substantially cylindrical shape with both ends sealed in this embodiment (see FIG. 2), it may be conical, trapezoidal, hemispherical, or the like when viewed from the side. For example, if the connecting portion between the outlet channel 511 and the sealing surface 505 is shaped like a funnel, bubbles in the fluid chamber 501 described later can be easily discharged.
A connection channel pipe 200 is connected to the outlet channel pipe 510. A connection channel 201 is formed in the connection channel pipe 200. The diameter of the connection channel 201 is formed larger than the diameter of the outlet channel 511. Further, the thickness of the pipe portion of the connection flow path pipe 200 is formed in a range having rigidity that does not absorb the pressure pulsation of the fluid.
A nozzle 211 is inserted into the distal end portion of the connection flow channel pipe 200. A fluid ejection port 212 is formed in the nozzle 211. The diameter of the fluid ejection port 212 is smaller than the diameter of the connection channel 201.

On the side surface of the upper case 500, an inlet channel tube 502 into which the connection tube 25 that supplies fluid from the pump 20 is inserted is projected. A connection channel 504 on the inlet channel side is formed in the inlet channel tube 502. The connection channel 504 communicates with the inlet channel 503. The inlet channel 503 is formed in a groove shape on the peripheral edge of the sealing surface 505 of the fluid chamber 501 and communicates with the fluid chamber 501.
A packing box 304 is formed on the lower case 301 side and a packing box 506 is formed on the upper case 500 side at a position spaced apart in the outer peripheral direction of the diaphragm 400 on the joint surface between the upper case 500 and the lower case 301. A ring-shaped packing 450 is mounted in a space formed by the packing box 304 and the packing box 506.

Here, when the upper case 500 and the lower case 301 are assembled, the peripheral portion of the diaphragm 400 and the peripheral portion of the reinforcing plate 410 are the peripheral portion of the sealing surface 505 of the upper case 500 and the concave portion 303 of the lower case 301. It is closely attached by the bottom. At this time, the packing 450 is pressed by the upper case 500 and the lower case 301 to prevent fluid leakage from the fluid chamber 501.
The fluid chamber 501 is in a high pressure state of 30 atm (3 MPa) or more when fluid is discharged, and the fluid may slightly leak at the joints of the diaphragm 400, the reinforcing plate 410, the upper case 500, and the lower case 301. However, the packing 450 prevents leakage.
When the packing 450 is disposed as shown in FIG. 2, the packing 450 is compressed by the pressure of the fluid leaking from the fluid chamber 501 at a high pressure, and is further pressed against the walls in the packing boxes 304 and 506. Leakage can be more reliably prevented. From this, a high pressure rise in the fluid chamber 501 can be maintained during driving.

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

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

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

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

FIG. 5 is a schematic configuration diagram of the distance detection means and the control means.
The distance detection means 40 detects the distance between the fluid ejection port 212 and the surface of the surgical target site (fluid ejection target). As shown in FIG. 5, the distance detection unit 40 includes a light source unit 41 that emits light, an optical transmission unit 42, a light receiving unit 43, and a signal processing unit 44.
As the light source unit 41, a semiconductor laser, a light emitting diode, or the like can be used. In the present embodiment, a pulse laser is used as the light source unit 41 and emits light at a predetermined cycle.
As the optical transmission unit 42, an optical fiber is used in this embodiment. The light transmission unit 42 guides the light emitted from the light source unit 41 to the distal end portion (fluid ejection port 212) of the connection flow channel tube 200 and emits the light toward the surface of the surgical target site. In addition, the light transmission unit 42 receives the reflected light reflected on the surface of the surgical target site by the light emitted toward the surface of the surgical target site, and guides the received reflected light to the light receiving unit 43.

Specifically, as shown in FIG. 2, the optical transmission unit 42 is connected to the connection tube 25, the connection flow channel 504 and the outlet flow channel 511 of the pulsation generation unit 100, and the connection flow channel tube from the light source unit 41 of the distance detection unit 40. It is provided so as to extend along 200 connection flow paths 201. The distal end portion of the light transmission unit 42 extends to a position where the nozzle 211 is aligned with the fluid ejection opening 212. In this case, the light transmission unit 42 is provided at a position that does not obstruct the connection flow path 201 and the fluid ejection opening 212 of the connection flow path pipe 200. And the optical transmission part 42 radiate | emits the light radiate | emitted from the light source part 41 from the front-end | tip part. Moreover, the light transmission part 42 receives the reflected light which the emitted light reflected in the surface of the surgery object site | part by the front-end | tip part.
In the present embodiment, a photodiode is used as the light receiving unit 43. The light receiving unit 43 receives the reflected light guided by the light transmission unit 42 and inputs a signal corresponding to the received reflected light to the signal processing unit 44.

The signal processing unit 44 drives the light source unit 41 to emit light at a predetermined cycle. Further, the signal processing unit 44 calculates a phase difference between the cycle of light emitted from the light source unit 41 and the cycle of the signal corresponding to the reflected light input from the light receiving unit 43, and the connection flow is calculated based on the calculated phase difference. A distance between the distal end portion of the path tube 200 and the surface of the surgical target site (hereinafter referred to as a target distance) is calculated. Then, the signal processing unit 44 inputs the calculated object distance to the voltage control unit 32 of the control unit 30.
As shown in FIG. 5, the control unit 30 includes a pump control unit 31 that controls the pump 20 and a voltage control unit 32 that controls the piezoelectric element 401 of the pulsation generating unit 100.
The pump control unit 31 controls the pressure of the fluid that the pump 20 supplies to the pulsation generating unit 100.

The voltage control unit 32 controls the voltage applied to the piezoelectric element 401 of the pulsation generation unit 100 according to the object distance input from the signal processing unit 44. In this case, the voltage control unit 32 sets the voltage applied to the piezoelectric element 401 so that the pressure of the fluid ejected from the fluid ejection opening 212 increases as the object distance input from the signal processing unit 44 increases. Control. Preferably, the voltage control unit 32 controls the voltage applied to the piezoelectric element 401 so that the pressure of the ejected fluid on the surface of the surgical target site is constant even when the object distance changes. That is, even when the object distance changes, the voltage applied to the piezoelectric element 401 is controlled so as to maintain a constant incision or excision capability with respect to the surgical target site.
Here, the voltage control unit 32 calculates a voltage to be applied to the piezoelectric element 401 using a predetermined conversion formula for converting the distance into a voltage based on the object distance input from the signal processing unit 44. In addition, the voltage control unit 32 may determine a voltage to be applied to the piezoelectric element 401 using a predetermined conversion table for converting the distance into a voltage based on the object distance input from the signal processing unit 44.

FIG. 6 is a diagram illustrating an example of control of a voltage applied to the piezoelectric element by the voltage control unit.
Specifically, as shown in FIG. 6, the voltage control unit 30 increases the slope of the rising portion of the voltage in the waveform of the drive signal input to the piezoelectric element as the object distance input from the signal processing unit 44 increases. Is increased (the angle S is decreased). The voltage control unit 30 may increase the value of the peak voltage in the waveform of the drive signal input to the piezoelectric element as the object distance input from the signal processing unit 44 increases. Furthermore, the voltage control unit 30 may shorten the period of the waveform of the drive signal input to the piezoelectric element as the object distance input from the signal processing unit 44 is larger.

Next, processing executed by the distance detection unit 40 and the voltage control unit 32 will be described in more detail with reference to the drawings.
FIG. 7 is a flowchart showing processing executed by the distance detecting means and the voltage control unit.
Here, the distance detection means 40 and the voltage control unit 30 repeatedly execute the processing shown in FIG. 7 when a switch (not shown) for starting the ejection of fluid is operated by the surgeon. .
When the switch for starting the ejection of the fluid is operated by the surgeon, as shown in FIG. 7, first, in step S1, the pump control unit 31 of the control means 30 drives the pump 20, A fluid is supplied to the pulsation generator 100 at a constant pressure.

Next, in step S2, the signal control unit 44 of the distance detection unit 40 drives the light source unit 41 to emit light at a predetermined cycle. When the light source unit 41 is driven, the light emitted from the light source unit 41 is emitted toward the surface of the surgical site through the light transmission unit 42.
Next, in step S3, the light receiving unit 43 of the distance detecting unit 40 receives the reflected light reflected on the surface of the surgical target site. In this case, the light receiving unit 43 receives the reflected light reflected on the surface of the surgical target site via the light transmission unit 42. The light receiving unit 43 inputs a signal corresponding to the received reflected light to the signal processing unit 44.

Next, in step S <b> 4, the signal control unit 44 of the distance detection unit 40 calculates the object distance based on the signal input from the light receiving unit 43. Then, the signal control unit 44 inputs the calculated object distance to the voltage control unit 32 of the control unit 30.
Next, in step S <b> 5, the voltage control unit 32 of the control unit 30 adjusts (controls) the voltage applied to the piezoelectric element 401 of the pulsation generation unit 100 according to the object distance input from the signal control unit 44. . Then, when a drive signal is input from the voltage control unit 32 to the piezoelectric element 401, a pulsed fluid discharge, that is, a pulsating flow is generated in the connection channel 201.

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

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

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

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

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

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

After the fluid flow in the inlet channel 503 is restored, the pulsating flow from the nozzle 211 can be continuously ejected if the piezoelectric element 401 expands.
Further, in the operation of the pulsation generating unit 100 described above, the fluid chamber 501 has a substantially rotating body shape and includes an inlet channel 503 as a swirling flow generating unit, and the outlet channel 511 has a substantially rotating body shape. Therefore, a swirling flow is generated in the fluid chamber 501, and the bubbles contained in the fluid are quickly discharged from the outlet channel 511 to the outside.
Therefore, even in a minute volume change of the fluid chamber 501 by the piezoelectric element 401, a sufficient pressure increase can be obtained without hindering the pressure fluctuation by the bubbles.
Here, in the operation of the pulsation generating unit 100 described above, when the switch for starting the ejection of the fluid is operated by the operator to be in the ON state, the distance detecting unit 40 always calculates the object distance. And the voltage control part 32 of the control means 30 always adjusts the voltage applied to the piezoelectric element 401 of the pulsation generation | occurrence | production part 100 according to the target object distance input from the signal control part 44. FIG.

Thereby, in the water pulse knife 1, it is possible to appropriately adjust the pressure of the fluid ejected from the connection flow channel pipe 200 according to the distance between the fluid ejection port 212 and the surface of the surgical target site.
That is, in the water pulse knife 1, when adjusting the pressure of the fluid ejected from the fluid ejection port 212 according to the distance between the fluid ejection port 212 and the surface of the surgical target site, the pulsation communicating with the connection flow channel pipe 200 is achieved. The generator 100 is controlled. Thereby, compared with the case where the pump 20 is controlled, it is possible to adjust the pressure of the fluid ejected from the channel tube with high responsiveness according to the distance between the fluid ejection port 212 and the surgical target site. Become.
Moreover, since the water pulse knife 1 controls the pulsation generation | occurrence | production part 100 connected to the connection flow-path pipe | tube 200 when adjusting the pressure of the fluid to eject, generation | occurrence | production of a water hammer phenomenon can be suppressed.

In the water pulse knife 1, by providing the pulsation generating unit 100, the fluid ejected from the connection flow channel pipe 200 becomes a pulsating flow. Therefore, the change in the flow rate of the fluid to be ejected when the pressure of the fluid ejected from the fluid ejection port 212 is adjusted is smaller than that in the case of injecting a continuous flow. Thereby, when adjusting the pressure of the fluid ejected from the fluid ejection port 212 according to the distance between the fluid ejection port 212 and the surface of the surgical target site, adjustment of a suction pump (not shown) becomes unnecessary.
In particular, in the water pulse knife 1, even when the distance between the fluid ejection port 212 and the surface of the surgical target site is changed, the pressure of the jetted fluid on the surface of the surgical target site can be controlled to be constant. . Thereby, even when the distance between the fluid ejection port 212 and the surface of the surgical target site changes, it is possible to maintain a constant incision or excision capability with respect to the surgical target site.

Further, in the water pulse knife 1, the voltage applied to the piezoelectric element is controlled in accordance with the distance between the fluid ejection port 212 and the surgical target site, and therefore the adjustment of the pressure of the fluid ejected from the fluid ejection port 212 is simplified. .
Further, in the water pulse knife 1, the light emitted from the light source 41 is guided to the distal end portion (fluid ejection port 212) of the connection flow channel tube 200, and the reflected light reflected on the surface of the surgical target site is guided. By having the optical transmission part 42 to be used, when exchanging the distance detecting means 40 in accordance with the exchange of the connection flow path pipe 200, it is only necessary to exchange the optical transmission part 42, so that the cost can be reduced.

It should be noted that the present invention is not limited to the above-described embodiment, but includes modifications and improvements as long as the object of the present invention can be achieved.
For example, in the above-described embodiment, the light emitted from the light source unit 41 is guided to the distal end portion (fluid ejection port 212) of the connection flow channel tube 200, and the reflected light reflected on the surface of the surgical target site is guided. The optical transmission unit 42 is included. However, the light transmission unit 42 may not be provided, and the light source unit 41 and the light receiving unit 43 may be arranged at the distal end portion of the connection channel tube 200.

  DESCRIPTION OF SYMBOLS 1 Water pulse knife (fluid ejection apparatus, fluid ejection surgical instrument), 20 Pump (fluid supply means), 30 Control means, 40 Distance detection means, 41 Light source part, 42 Light transmission part, 43 Light reception part, 44 Signal processing part, DESCRIPTION OF SYMBOLS 100 Pulsation generation | occurrence | production part, 120 Posture detection means, 200 Connection flow path pipe (flow path pipe), 201 Connection flow path, 212 Fluid ejection opening part (fluid ejection port), 401 Piezoelectric element (volume change means), 501 Fluid chamber, 503 inlet channel, 511 outlet channel.

Claims (6)

A pulsation generator having a fluid chamber into which fluid flows, volume changing means for changing the volume of the fluid chamber, and an inlet channel and an outlet channel communicating with the fluid chamber;
A flow path pipe having a connection flow path with one end communicating with the outlet flow path and the other end communicating with the fluid ejection port;
Fluid supply means for supplying fluid to the inlet channel;
Control means for controlling the change in volume of the fluid chamber by the volume changing means;
A distance detecting means for detecting a distance between the fluid ejection port and the fluid ejection object;
The fluid ejecting apparatus according to claim 1, wherein the control unit controls the change of the volume of the fluid chamber by the volume changing unit according to the distance detected by the distance detecting unit. The distance detecting means includes
A light source that emits light;
The light emitted from the light source part is guided to the fluid ejection port and emitted toward the fluid ejection object, and the light emitted toward the fluid ejection object is reflected by the fluid ejection object. An optical transmission unit that receives the reflected light and guides the received reflected light;
A light receiving unit that receives reflected light guided by the light transmission unit and outputs a signal corresponding to the received light;
A signal processing unit that calculates a distance between the fluid ejection port and the fluid ejection object based on the signal output by the light receiving unit;
The fluid ejecting apparatus according to claim 1, further comprising: The volume changing means is a piezoelectric element,
The fluid ejecting apparatus according to claim 1, wherein the control unit controls a voltage applied to the piezoelectric element in accordance with the distance detected by the distance detection unit.   The control unit controls the change of the volume of the fluid chamber by the volume changing unit so that the pressure of the fluid ejected from the fluid ejection port increases as the distance detected by the distance detection unit increases. The fluid ejecting apparatus according to claim 1, wherein the fluid ejecting apparatus is a fluid ejecting apparatus. A pulsation generator having a fluid chamber into which fluid flows, volume changing means for changing the volume of the fluid chamber, and an inlet channel and an outlet channel communicating with the fluid chamber;
A flow path pipe having a connection flow path with one end communicating with the outlet flow path and the other end communicating with the fluid ejection port;
Fluid supply means for supplying fluid to the inlet channel;
Control means for controlling the change in volume of the fluid chamber by the volume changing means;
A distance detecting means for detecting a distance between the fluid ejection port and the surgical target site;
The control means controls the change of the volume of the fluid chamber by the volume changing means according to the distance detected by the distance detecting means,
The fluid ejecting surgical instrument characterized in that the volume changing means changes the volume of the fluid chamber to incise or excise the surgical target site by the fluid ejected from the fluid ejection port. Supply fluid to the fluid chamber communicating with the connection flow path,
By changing the volume of the fluid chamber, the pressurized fluid is ejected from the fluid ejection port communicating with the connection flow path,
Detecting the distance between the fluid ejection port and the fluid ejection object;
The fluid ejecting method according to claim 1, wherein the change of the volume of the fluid chamber is controlled according to the detected distance.

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