OPERATION SECTION AND LIQUID EJECTION DEVICE

An operation section used to form a liquid ejection device that ejects liquid includes a tubular nozzle section through which the liquid is ejected, and a gripper section in which the nozzle section is so disposed as to protrude through one side of the gripper section and a tube group including a tube through which the liquid flows and a cable through which a drive signal is supplied is connected to another side of the gripper section, and the gripper section is provided with a finger position fixing section on which any of an operator's fingers rests when the operator grips the gripper section.

BACKGROUND

1. Technical Field

The present invention relates to an operation section having a nozzle section through which liquid is ejected and a liquid ejection device including the operation section.

2. Related Art

In recent years, in a medical field, such as an incision and removal of living tissue, a liquid ejection device is used because many advantages, such as an ability to maintain the surface of living tissue at a surgical operation site at a low temperature and no injury of blood vessels and bodily parts, attract attention. A liquid ejection device ejects liquid, such as physiological saline, in the form of pulsed flow toward a living body to excise or fragmentate living tissue. A practitioner grips a handpiece (hereinafter referred to as an operation section) including a nozzle through which the liquid is ejected for medical practice (see JP-A-9-224951, for example).

As medical treatment advances, a variety of kinds of biological sites become targets of the liquid ejection device, and more accurate medical practice is required. Some medical practices require a microscope or a magnifying glass. A plurality of tubes (hereinafter referred to as a tube group) are connected to the operation section of a liquid ejection device, including a supply tube through which liquid is supplied, a suction tube through which ejected liquid and fragmented tissue are sucked, and cables through which electric power and a control signal for generation of the pulsed flow are transmitted. Therefore, in the operation of the operation section, the tube group connected to the operation section bends and twists and therefore produces reaction force, so that the posture of the operation section tends to be unstable, resulting in a difficulty in accurate operation.

SUMMARY

Application Example 1

This application example is directed to an operation section used to form a liquid ejection device that ejects liquid, the operation section including a tubular nozzle section through which the liquid is ejected and a gripper section in which the nozzle section is so disposed as to protrude through one side of the gripper section and a tube group including a tube through which the liquid flows and a cable through which a drive signal is supplied is connected to another side of the gripper section, wherein the gripper section is provided with a finger position fixing section on which any of an operator's fingers rests when the operator grips the gripper section.

According to the configuration described above, even when the tube group, that is, the tube and the cable are connected to the operation section, the operator who grips the operation section for operation can grip the operation section with at least one finger resting on the finger position fixing section of the gripper section. The gripper section can therefore be firmly gripped for stabilization of the posture of the operation section. As a result, the operator can readily control the position of the front end of the nozzle section of the operation section. An operation section of a liquid ejection device that allows accurate medical practice with excellent operability can be provided.

Application Example 2

In the operation section described above, the gripper section may have a roughly cylindrical portion, the tubular nozzle section may be so disposed as to obliquely protrude at a predetermined angle with respect to an axial line of the gripper section, and the finger position fixing section may be a protrusion so disposed as to protrude in a direction facing an obtuse angle formed by an axial line of the nozzle section and the axial line of the gripper section.

According to the configuration described above, the liquid ejected through the nozzle section is ejected in a direction slightly inclined to the axial line of the gripper section. Further, the finger position fixing section is disposed as a protrusion that protrudes outward within the range of the obtuse angle (in the direction facing the obtuse angle) formed by the axial lines of the nozzle section and the gripper section. Therefore, when the operator grips the gripper section of the operation section, many fingers can be placed in the direction facing the obtuse angle, and at least one finger can be firmly placed on the finger position fixing section to firmly grip the gripper section. The obtuse angle used herein refers to an angle formed by two half lines and satisfying 90°<θ<180°.

The operator can therefore stabilize the posture of the operation section while checking an ejection position where the liquid is ejected through the nozzle section. An operation section of a liquid ejection device that allows accurate medical practice with excellent operability can therefore be provided. The operator can instead operate the operation section with the thumb placed in the direction facing a reflex angle direction corresponding to the obtuse angle described above, with the index finger resting on the finger position fixing section, and with the other fingers placing in the direction facing the obtuse angle. The reflex angle used herein refers to an angle formed by two half lines and satisfying 180°<θ<360°.

Application Example 3

In the operation section described above, the tube group may include a cable for transmitting a drive signal to an ejection drive section that causes the liquid to be ejected through the nozzle section, a supply tube for supplying the ejection drive section with the liquid, and a suction tube for sucking the ejected liquid.

According to the configuration described above, an operation section of a liquid ejection device that allows the ejection drive section to eject the liquid supplied through the supply tube through the nozzle section and suck the ejected liquid containing fragmentated living tissue with excellent operability can be provided.

Application Example 4

In the operation section described above, the gripper section may be provided with a suction adjuster that adjusts suction force by which the liquid is sucked through the suction tube.

According to the configuration described above, the suction of the liquid ejected by the ejection drive section through the nozzle section and the liquid containing fragmentated tissue can be initiated and terminated and the suction force can be adjusted in accordance with situations of a patient and the patient's surroundings. An operation section with excellent operability can therefore be provided.

Application Example 5

In the operation section described above, the suction adjuster may be a hole section that is disposed in a direction facing a reflex angle corresponding to the direction facing the obtuse angle formed by an axial line of the nozzle section of the gripper section and an axial line of the gripper section, opens through an outer circumferential surface of the gripper section, and communicates with the suction tube via an outer circumference thereof, and the operator may change an open area of the hole section with a finger to adjust suction force by which the liquid is sucked through the suction tube while gripping the gripper section.

According to the configuration described above, the operator can place, for example, the operator's thumb on the hole section of the suction adjuster disposed in the gripper section and in the direction facing the reflex angle and can further rest at least one finger, for example, the index finger on the finger position fixing section and place the other fingers in the direction facing the obtuse angle to grip the gripper section. The operator can therefore move the thumb freely to some extent while firmly gripping the gripper section to adjust the suction force by changing the open area of the hole section with the thumb. As a result, even in the structure having the suction adjuster, the posture of the operation section can be stabilized. An operation section of a liquid ejection device that allows accurate medical practice with excellent operability can therefore be provided.

Application Example 6

In the operation section described above, the finger position fixing section may be movable along an axial line of the gripper section.

According to the configuration described above, the finger position fixing section can be moved to an optimum position in accordance with the size of a practitioner's hands, how the practitioner grips the operation section, and other factors. As a result, an operation section of a liquid ejection device that is highly versatile and readily operated can therefore be provided.

Application Example 7

In the operation section described above, the finger position fixing section may be attachable and detachable to and from the gripper section.

According to the configuration described above, special usage that allows special control of the nozzle section can be achieved. Further, the operation section can be stored in a space-saving manner.

Application Example 8

This application example is directed to a liquid ejection device including the operation section described in any of the application examples having an ejection drive section that causes liquid to be ejected through a nozzle section, a device main body section including a liquid supply mechanism that supplies the operation section with at least the liquid and a liquid suction mechanism that sucks the liquid through the nozzle section, and a tube group connected between the operation section and the device main body section and including a tube through which the liquid flows and a cable through which a drive signal is supplied.

According to the configuration described above, a liquid ejection device including the operation section that has excellent operability and allows the ejection drive section to cause the liquid supplied from the liquid supply mechanism to be ejected through the nozzle section for medical practice and liquid containing fragmentated tissue to be sucked at desired suction force in accordance with situations of a patient and the patient's surroundings can be provided.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Embodiments of the invention will be described below with reference to the drawings. In the drawings that the following description refers to, a member or a portion is drawn at an aspect ratio different from an actual aspect ratio in some cases for ease of description and illustration.

Overall Configuration of Liquid Ejection Device

An overall configuration of a liquid ejection device10will be described with reference toFIG. 1.FIG. 1is a schematic view showing the overall configuration of the liquid ejection device10. The liquid ejection device10is primarily used for medical treatment and ejects a liquid L, for example, physiological saline and Ringer's solution, in the form of pulsed flow toward a medical practice target site to excise or fragmentate tissue. The liquid ejection device10includes a device main body section20and an operation section50, as shown inFIG. 1. The device main body section20and the operation section50are connected to each other via a tube group15.

Device Main Body Section

The device main body section20will first be described with reference toFIG. 1. The device main body section20includes a roughly box-shaped enclosure21and accommodates a liquid supply mechanism30, a liquid suction mechanism40, and a controller25, as shown inFIG. 1.

The enclosure21is provided with a display section22and a switch section23. The display section22is formed, for example, of a liquid crystal display and displays the quantity, the flow speed, and the pressure of the supplied liquid L ejected by the liquid ejection device10and other types of necessary information on the liquid L. The switch section23includes at least a power switch24and an ejection switch26. The power switch24is a switch that activates the liquid ejection device10. When the power switch24is flipped on, electric power is supplied to the device main body section20. The ejection switch26is a switch that switches the action of the operation section50between ejection and no ejection of the liquid L therefrom. The ejection switch26is preferably formed, for example, of a foot switch operated with a practitioner's foot.

The liquid supply mechanism30has a function of supplying the operation section50with the liquid L ejected from the liquid ejection device10and includes a liquid storage32, a supply pump34, and a supply quantity adjuster36, which are sequentially arranged along the flow of the liquid L (arrow A). The liquid storage32is what is called a liquid reservoir and stores the liquid L, such as physiological saline and Ringer's solution, which is ejected from the liquid ejection device10. Physiological saline and Ringer's solution, which hardly harm a living body, can be used in surgery.

The supply pump34can be, for example, a syringe-type pump or a tube pump. When a syringe-type pump is used, it is preferable to separately provide a device that supplies the liquid L into the syringe in consideration of continuous driving operation. A liquid acquisition tube34ais attached to the supply pump34, and an end portion of the liquid acquisition tube34ais connected to the liquid storage32. The supply pump34performs sucking action in the direction indicated by the arrow A to deliver the liquid L stored in the liquid storage32in the direction indicated by the arrow A.

The supply quantity adjuster36is provided in a halfway position along a supply tube12, which is connected to the supply pump34, and includes a supply flowmeter37and an electromagnetic valve38. The supply flowmeter37measures the flow rate of the liquid L flowing through the supply tube12. The supply flowmeter37can be, for example, a hot wire flowmeter or a turbine flowmeter. The electromagnetic valve38is a valve so controlled with an electric signal as to open and close, and opening and closing the valve controls the flow of the liquid L flowing through the valve. The supply quantity adjuster36operates the electromagnetic valve38on the basis of a result of the measurement performed by the supply flowmeter37to adjust the flow rate of the liquid L flowing through the supply tube12. The supply tube12is held by the operation section50, which will be described later. The supply tube12will be described later in detail.

The liquid suction mechanism40has a function of sucking a liquid M containing part of fragmentated tissue left after the liquid L is ejected from the liquid ejection device10for medical practice. The liquid suction mechanism40further has a function of sucking excess liquid L used in medical practice in order to ensure the field of vision of the practitioner during the medical practice. It is, however, assumed that the entire liquid sucked by the liquid suction mechanism40is referred to as the liquid M for ease of description.

The liquid suction mechanism40includes a suction flowmeter46, a suction pump44, and a drainage tank42, which are sequentially arranged along the flow of the liquid M (arrow B). The suction flowmeter46has the same structure as that of the supply flowmeter37described above and is provided in a halfway position along a suction tube14held by the operation section50, which will be described later. The suction flowmeter46measures the flow rate of the liquid M flowing through the suction tube14. The suction pump44is not limited to a specific pump and can be, for example, a tube pump. The suction pump44performs sucking action in the direction indicated by the arrow B.

A drainage tube44ais attached to the suction pump44, and an end portion of the drainage tube44ais connected to the drainage tank42. The drainage tank42is what is called a liquid reservoir and stores the liquid M containing part of post-medical-practice fragmentated tissue sucked by the operation section50of the liquid ejection device10. The liquid suction mechanism40can be further provided, as required, with a filter that is not shown but is provided along the flow path for removal of part of the fragmentated tissue.

The controller25is connected to the display section22, the switch section23, the liquid supply mechanism30, and the liquid suction mechanism40described above via an internal cable17and oversees and controls the mechanisms described above. The controller25is connected to the operation section50, which will be described later, via a cable18, which forms the tube group15.

Operation Section

A summary of the operation section50will next be described with reference toFIGS. 2A to 2CandFIG. 3.FIGS. 2A to 2Care schematic configuration diagrams showing the operation section50.FIG. 2Ais an exterior appearance view.FIG. 2Bis a cross-sectional view of a nozzle section.FIG. 2Cshows the front end of the nozzle.FIG. 3is a diagrammatic cross-sectional view showing the internal configuration of a pulsed flow applying part60. The operation section50is a portion gripped with the practitioner's hand and operated by the practitioner for medical practice, as shown inFIG. 2A. The operation section50includes a nozzle section52, a gripper section58, and a connection section77, which are sequentially arranged from a medical practice target site when viewed with the operation section50facing the medical practice target site.

The nozzle section52includes an ejection tube54and a suction tube14a,each of which is a hollow tube, as shown inFIGS. 2B and 2C. In the present embodiment, the ejection tube54is, for example, a small-diameter tube through which the liquid L is ejected to a medical practice target site. The ejection tube54is inserted into the suction tube14a,the inner diameter of which is greater than the outer diameter of the ejection tube54. That is, the ejection tube54is disposed at the center of the nozzle section52, and the suction tube14asurrounds the ejection tube54. An ejection port54bof the ejection tube54and a suction port14bof the suction tube14aare roughly flush with each other in a basic setting but can be positionally adjusted.

The present embodiment has been described with reference to the case where the ejection tube54is inserted into the suction tube14a,but this configuration is not necessarily employed. The ejection tube54and the suction tube14amay be disposed side by side, or the suction tube14amay be disposed at the center and the ejection tube54may surround the suction tube14a.Still instead, the suction tube14amay be an extension of the suction tube14, which forms the tube group15, or may communicate with the suction tube14via a separate tube.

The gripper section58includes a main body case59, the pulsed flow applying part60shown inFIG. 3, and a suction adjuster75. The main body case59is preferably formed of a molded part made, for example, of a plastic material and has a roughly cylindrical shape so deformed that a portion close to a medical practice target site slightly narrows. The gripper section58is a portion gripped by the practitioner and is precisely operated for excision or fragmentation of living tissue at a medical practice target site with the ejection port54bof the ejection tube54facing the medical practice target site. In this process, the practitioner passes the operation section50from the right hand to the left hand or vice versa and changes the way the operation section50is gripped in accordance with a variety of situations, such as provision of a secure field of vision with the aid of a microscope or a magnifying glass, the direction in which a target site is excised, and other medical practice tools to be used.

The pulsed flow applying part60as an ejection drive section is accommodated in the main body case59. The gripper section58will be described later in detail.

The pulsed flow applying part60includes a first case70, a second case71, a third case72, a piezoelectric element62, a diaphragm64, an inlet channel67, an outlet channel68, and a pump chamber66, as shown inFIG. 3. The second case71is a tubular member and has one end that forms a flange, and the flange faces the first case70and is bonded thereto. The other end of the second case71is bonded to the third case72, and a cylindrical space is formed in the second case71. The piezoelectric element62is disposed in the interior space of the second case71.

The piezoelectric element62is a laminated piezoelectric element and forms an actuator. One end of the piezoelectric element62on the side facing the first case70is firmly fixed to the diaphragm64, and the other end of the piezoelectric element62is firmly fixed to the third case72. The cable18is connected to the other end of the piezoelectric element62, and the piezoelectric element62receives, through the other end thereof, a drive signal transmitted from the controller25in the device main body section20. The diaphragm64is formed of a disk-shaped metal thin film, and the periphery of the diaphragm64is firmly fixed to the second case71. The pump chamber66, which is a space having a predetermined volume, is formed between the diaphragm64and the first case70, and the volume changes in accordance with the action of the piezoelectric element62driven with the drive signal.

The inlet channel67and the outlet channel68are formed in the first case70. The inlet channel67communicates with the side surface of the pump chamber66. A channel69guided from the supply tube12described above is connected to the inlet channel67. The liquid L supplied from the device main body section20is therefore supplied via the supply tube12, the channel69, and the inlet channel67into the pump chamber66. The outlet channel68communicates with a surface of the pump chamber66, that is, the surface thereof perpendicular to the direction in the piezoelectric element62is displaced. The ejection tube54in the nozzle section52is connected to the outlet channel68. The suction tube14ain the nozzle section52passes by the pulsed flow applying part60and extends toward the connection section77, which will be described later.

The suction adjuster75is provided in the main body case59and in a portion where the outer diameter of the exterior of the main body case59slightly decreases, as shown inFIG. 2A. In the present embodiment, the suction adjuster75is formed as an open hole section75a,and one end of the hole section75acommunicates with the outside air and the other end thereof connects to the inner wall of the suction tube14a. The interior of the suction tube14ais sucked at predetermined pressure by the liquid suction mechanism40in the device main body section20. The sucking action can therefore be initiated or terminated and suction force can be adjusted by opening or closing the hole section75aof the suction tube14aor changing the open area of the hole section75a.That is, the practitioner who grips the main body case59adjusts the suction adjuster75by opening or closing the hole section75aor adjusting the open area of the hole section75awith the thumb or the index finger.

The present embodiment has been described with reference to the case where the suction adjuster75is formed as the open hole section75aand the practitioner operates the suction adjuster75with a finger, but the suction adjuster is not necessarily configured this way. The suction adjuster75may be operated, for example, with a slide switch or a foot switch.

The connection section77has a roughly disk-plate-shaped connection surface78and is disposed on the opposite side of the main body case59with respect to the side where the nozzle section52is provided. The tube group15, which includes the supply tube12, the suction tube14, and the cable18, is connected to the connection surface78. The position on the connection surface78where the tube group15is connected thereto is not particularly specified.

The tube group15will now be described in detail. The connection section77holds the tube group15including the supply tube12, the suction tube14, and the cable18, as shown inFIG. 2A. In the present embodiment, the supply tube is preferably formed of a tube made, for example, of high-density polyethylene. A tube made of high-density polyethylene excels in water resistance and chemical resistance and has other advantages. The suction tube14is preferably formed of a tube made, for example, of polyurethane. A tube made of polyurethane excels in tensile resistance and flexibility and has other advantages.

The cable18accommodates a power line and a signal line therein, and the exterior of the cable18is coated with a synthetic resin, such as silicon and polyvinyl chloride. Polyvinyl chloride excels in heat resistance, flame retardation, and environmental friendliness and has other advantages. Silicon has properties as an elastic material maintained over a wide temperature range and shows excellent resistance to ozone, humidity, electrical insulation, hot water, and chemicals.

In the present embodiment, the outer diameter of each of the tubes in the tube group15is so set that the supply tube12has the thinnest outer diameter ranging from about 2 to 3 mm and the suction tube14and the cable18have greater outer diameters or the diameters of the supply tube12, the suction tube14, and the cable18increase in this order. During medical practice, the supply tube12is roughly always filled with the liquid L, and the liquid M containing part of fragmentated tissue flows inside the suction tube14in an intermittent or continuous manner. The cable18accommodates a power line and a signal line therein.

The tubes in the tube group15therefore differ from one another in terms of rigidity. The rigidity used herein refers to the magnitude of force required to bend or twist each of the tubes or the magnitude of reaction force produced by each of the tubes when the tube attempts to restore the initial shape. Further, the degree of rigidity is determined by the outer diameter and the thickness of each of the tubes, whether or not the liquid L or M flows through the tube, the content accommodated in the tube, and other factors. The tube group15including the supply tube12, the suction tube14, and the cable18is connected between the device main body section20and the operation section50, and each of the tubes has a length of several meters.

Action of Liquid Ejection Device

The action of the liquid ejection device10will next be described with reference toFIGS. 1 to 3. In the liquid ejection device10having the configuration described above, when the power switch24on the device main body section20shownFIG. 1is flipped on, electric power is supplied to the controller25. The practitioner grips the operation section50, orients the nozzle section52toward a medical practice target site, and flips on the ejection switch26.

When the ejection switch26is flipped on, the supply pump34in the liquid supply mechanism30is activated, extracts the liquid L stored in the liquid storage32through the liquid acquisition tube34a,and causes the liquid L to flow to the electromagnetic valve38. When the controller25opens the electromagnetic valve38, the liquid L travels as a fluid inside the supply tube12disposed in the device main body section20. In this process, the supply flowmeter37detects the flow rate of the liquid L traveling inside the supply tube12and outputs the detected flow rate to the controller25. The action of the supply flowmeter37allows adjustment of the quantity and pressure of the liquid L delivered from the device main body section20. Further, the quantity and pressure of the liquid L are displayed in the display section22on the device main body section20.

The liquid L delivered from the device main body section20travels inside the supply tube12, which forms the tube group15, which is connected between the device main body section20and the operation section50, and reaches the operation section50. The liquid L having reached the operation section50travels via the channel69and the inlet channel67, which are provided in the gripper section58, and fills the pump chamber66in the pulsed flow applying part60.

The volume of the pump chamber66changes in accordance with the action of the piezoelectric element62. That is, the piezoelectric element62expands or contracts in the direction indicated by the arrow A or B inFIG. 3in response to the drive signal transmitted from the controller25in the device main body section20via the cable18. When the piezoelectric element62expands in the direction indicated by the arrow A, the diaphragm64is pressed and bent by the piezoelectric element62in the direction indicated by the arrow A inFIG. 3, resulting in a decrease in the volume of the pump chamber66. The liquid L in the pump chamber66is therefore pushed out of the pump chamber66and travels to the outlet channel68. The liquid L traveling through the outlet channel68travels inside the ejection tube54, which communicates with the outlet channel68, in the nozzle section52and is ejected through the ejection port54b.

When the piezoelectric element62contracts in the direction indicated by the arrow B, the diaphragm64is bent in the B direction inFIG. 3in synchronization with the action of the piezoelectric element62, resulting in an increase in the volume of the pump chamber66. The liquid L is therefore supplied into the pump chamber66through the inlet channel67. That is, driving the piezoelectric element62at a predetermined frequency allows the liquid L supplied from the liquid supply mechanism30in the device main body section20to be ejected through the ejection tube54in the form of pulsed jet flow. The liquid L ejected through the ejection tube54in the form of pulsed jet flow excises or fragmentates tissue at a medical practice target site.

At this point, the liquid M containing part of the fragmentated tissue and excess liquid L that blocks the field of vision during medical practice are also present at the medical practice target site. The following description will be made on the assumption that the liquid L once ejected through the ejection tube54is entirely converted into the liquid M for ease of description. The liquid M is sucked by the liquid suction mechanism40.

When the practitioner flips the ejection switch26on, not only is the supply pump34activated, but also the suction pump44in the liquid suction mechanism40is activated roughly at the same time. The suction pump44performs sucking action in the direction indicated by the arrow B inFIG. 3in the channel including the suction tubes14and14a.As a result, the pressure in the suction tube14ain the operation section50goes negative, and the liquid M present around the suction port14bof the suction tube14ais sucked.

The operation section50has the suction adjuster75, as described above. The suction adjuster75is formed as the open hole section75a.The practitioner opens or closes the hole section75aor changes the open area with the thumb or the index finger while gripping the main body case59. The practitioner can thus perform and terminate suction of the liquid M and adjust the quantity of sucked liquid M. The liquid M can be sucked in a state in which the liquid L is ejected through the ejection port54bor in a state in which the ejection switch26is flipped off to stop ejecting the liquid L through the ejection port54b.The adjustment of the quantity of sucked liquid M is preferably made in a state in which the liquid M stays at the medical practice target site or a state in which the field of vision is ensured during the medial practice.

The liquid M sucked through the suction port14btravels through the suction tube14ain the operation section50and the suction tube14connected to the suction tube14ainto the suction tube14in the device main body section20. The liquid M having traveled into the device main body section20travels through the suction flowmeter46, the suction pump44, and the drainage tube44aand is stored in the drainage tank42. The suction flowmeter46detects the flow rate of the liquid M traveling inside the suction tube14and outputs the detected flow rate to the controller25. The suction flowmeter46senses whether the suction is being reliably performed, how much of liquid M is stored in the drainage tank42, and other conditions.

Finger Position Fixing Section

First Embodiment

A finger position fixing section according to a first embodiment will be described with reference toFIGS. 4A and 4B.FIGS. 4A and 4Bdescribe the finger position fixing section according to the first embodiment.FIG. 4Ashows the finger position fixing section according to the first embodiment (roughly the same asFIG. 2A) , andFIG. 4Bshows an example in which the practitioner grips the operation section50. To identify the finger position fixing section in the following description, the finger position fixing section is referred to as a finger position fixing section80, whereas to identify the finger position fixing section in each embodiment, the finger position fixing section80is followed by a suffix, such as finger position fixing sections80a,80b,. . . for distinction purposes. The same holds true for the other components.

The nozzle section52of the operation section50is inclined to the axial line of the main body case59of the gripper section58by a predetermined angle, and the axial lines of the nozzle section52and the main body case59form an obtuse angle θ, as shown inFIG. 4A. The obtuse angle used herein refers to an angle formed by two half lines and satisfying 90°<θ<180°. In other words, the direction in which the liquid is ejected through the nozzle section52is inclined by (180°-θ) to the direction in which the practitioner grips the operation section50. The reason for this is that the inclined nozzle section52allows the practitioner to fully recognize a medical practice target site when the practitioner performs the medical practice. In particular, when medical practice is performed by using a microscope or a magnifying glass, the inclined nozzle section52prevents the front end of the main body case59or the nozzle section52from blocking the field of view of the microscope or the magnifying glass. When the liquid is ejected downward, the inclined nozzle section52is further effective.

A finger position fixing section80aaccording to the first embodiment is provided in the direction facing the obtuse angle θ of the operation section50and in the vicinity of the position where the axial line of the nozzle section52intersects the axial line of the gripper section58. The finger position fixing section80ais formed as part of the main body case59, is a protrusion that protrudes in the direction facing the obtuse angle, and has a finger rest section82aon the side facing the nozzle section52. The finger rest section82ais formed as an arcuate recess and allows any of the fingers of the practitioner to rest on. Further, the hole section75aof the suction adjuster75described above is disposed in the direction facing a reflex angle (360°-θ) corresponding to the obtuse angle θ formed by the axial lines of the nozzle section52and the gripper section58and in a position roughly facing away from the finger position fixing section80a.The reflex angle used herein refers to an angle formed by two half lines and satisfying 180°<θ<360°.

When the practitioner grips the operation section50including the finger position fixing section80aaccording to the first embodiment, the index finger, for example, is rested on the finger rest section82aof the finger position fixing section80a,and the middle finger to the little finger are used to support the main body case59from below, as shown inFIG. 4B. In this state, the thumb reaches the suction adjuster75positioned in the direction facing the reflex angle (360°-θ). That is, the practitioner can naturally place the ball of the thumb on the hole section75aof the suction adjuster75. The present embodiment is presented by way of example, and another finger can be placed on the hole section75adepending on a medical practice target site and how to grip the operation section50.

Advantageous effects provided by the first embodiment will be described below.

(1) When the practitioner grips the operation section50including the position fixing section80adescribed above, at least one finger, for example, the index finger, is rested on the finger rest section82aof the finger position fixing section80aand the other fingers are placed in the direction facing the obtuse angle θ for firm grip of the gripper section58. The gripper section58can thus be firmly gripped for stabilization of the posture of the operation section50. As a result, the practitioner can readily control the position of the front end of the nozzle section52of the operation section50while checking the position where the liquid ejected through the nozzle section52is landed. Therefore, even when the operation section50is operated and the tube group15connected to the operation section50bend or twist to produce reaction force, the operation section50of the liquid ejection device10provided by the present embodiment allows accurate medical practice with excellent operability.

(2) The operation section50including the finger position fixing section80adescribed above allows the practitioner to place a thumb on the hole section75aof the suction adjuster75disposed in the gripper section58and in the direction facing the reflex angle. The practitioner can therefore move the thumb freely to some extent while firmly gripping the gripper section58to readily adjust the suction force by changing the open area of the hole section75awith the thumb. As a result, even in the structure having the suction adjuster75, the posture of the operation section50can be stabilized. The operation section50of the liquid ejection device10provided by the present embodiment therefore allows accurate medical practice with excellent operability.

Variations of First Embodiment

A variety of changes can be made to the first embodiment described above to the extent that the changes do not depart from the substance of the invention. For example, variations different from the embodiment described above will be described with reference toFIGS. 5A to 5C.FIGS. 5A to 5Cshow variations of the first embodiment.

The embodiment described above has been described with reference to the case where the finger position fixing section80ais formed as a single arcuate recess, but the finger position fixing section is not necessarily configured this way. The finger position fixing section may be a finger position fixing section80bshown inFIG. 5A, which has, in addition to the arcuate recess positioned in the direction toward the nozzle section52, a finger rest section82b,which is formed along a lower portion of the main body case59and formed of a plurality of arcuate recesses on which the other fingers rest. The operation section50including the finger position fixing section80ballows the practitioner to firmly grip the gripper section58of the operation section50even in medical practice using liquid.

The finger position fixing section may be a finger position fixing section80cshown inFIG. 5B, which is formed of an annular finger rest section82cprovided in the vicinity of the position where the axial line of the nozzle section52intersects the axial line of the gripper section58. The operation section50including the finger position fixing section80cnot only allows the practitioner to firmly grip the gripper section58of the operation section50even in medical practice using liquid but also prevents the practitioner from dropping the operation section50.

The finger position fixing section may be a finger position fixing section80dshown inFIG. 5C, which is formed, for example, of a plate-shaped finger rest section82d,which is narrow in the direction toward the nozzle section52but long in the downward direction inFIG. 5C. The thus shaped finger rest section82dallows an increase in the flexibility in the finger rest position and further allows a space for the other fingers to be provided in the direction toward the nozzle section52. Therefore, the practitioner can firmly grip the gripper section58of the operation section50, and the flexibility in how to grip the gripper section58increases.

Second Embodiment

A finger position fixing section according to a second embodiment will be described with reference toFIGS. 6A and 6B.FIGS. 6A and 6Bdescribe the finger position fixing section according to the second embodiment.FIG. 6Ais an exterior perspective view of the finger position fixing section, andFIG. 6Bshows an aspect in which the finger position fixing section is attached to the operation section. The same configurations and contents as those in the first embodiment have the same reference characters and will not be described.

A finger position fixing section80eaccording to the second embodiment is a part independent of the main body case59of the operation section50. The finger position fixing section80eis preferably formed, for example, in metal sheet processing and has a finger rest section82eand an attachment section85e,as shown inFIG. 6A. The attachment section85eis formed of a metal sheet so bent and shaped as to follow the bottom surface of the main body case59, and raised portions formed on opposite sides of the attachment section85ehave elongated holes86extending in the longitudinal direction thereof. The finger rest section82ehas a roughly same shape as the shape of the finger rest section82d,which is one of the variations of the first embodiment. That is, the finger rest section82eis a rectangular sheet with an arcuate recess. In the present embodiment, the finger rest section82eis formed by cutting part of the metal sheet that forms the attachment section85eand bending the cut part.

A description will be made of a method for attaching the finger position fixing section80edescribed above to the operation section50and the function of the finger position fixing section80e.The attachment section85eof the finger position fixing section80eis disposed on the bottom surface of the main body case59of the operation section50, as shown inFIG. 6B. In the present embodiment, two threaded holes that are not shown are formed through the side surface of the main body case59and in positions corresponding to the elongated holes86in the raised portions of the attachment section85e. The finger position fixing section80eis therefore attached to the operation section50, for example, by fastening commercially available screws87through the elongated holes86in the attachment section85e.

Since the elongated holes86are formed in the attachment section85eof the finger position fixing section80e,the finger position fixing section80e,that is, the finger rest section82ecan be moved in the direction indicated by the arrow S inFIG. 6Bby loosening the screws87and then placed in an arbitrary position by fastening the screws87. Further, the finger position fixing section80ecan be removed from the operation section50by loosening and removing the screws87.

Advantageous effects provided by the second embodiment will be described below.

The finger position fixing section80edescribed above is attachable and detachable to and from the main body case59of the operation section50by attaching and detaching the screws87. Therefore, when the operation section50is stored, carried, or otherwise handled, the finger position fixing section80ecan be detached for space saving. Further, the practitioner can grip the operation section50in a manner different from the manner described with reference toFIG. 4Bby detaching the finger position fixing section80e.For example, the practitioner can so grip the operation section50as to place the index finger on the hole section75aof the suction adjuster75and surround the gripper section58with the other fingers. The operation section50provided by the second embodiment can therefore be a highly versatile operation section.

Since the elongated holes86are formed in the attachment section85eof the finger position fixing section80edescribe above, the finger rest section82ecan be moved in the direction indicated by the arrow SinFIG. 6Bby loosening the screws87and placed in an arbitrary position by fastening the screws87. The finger rest section82ecan therefore be moved and adjusted in an optimum position in accordance with the size of the practitioner's hands and how the practitioner grips the operation section50. As a result, the operation section50provided by the second embodiment can be readily operated.

The second embodiment has been described with reference to the case where the finger rest section82d,which is one of the variations of the first embodiment, is used as the finger rest section82, and the finger rest section82dis presented by way of example and is not necessarily used. Any of the finger rest sections82described in the first embodiment or any other finger rest section82can be used. Further, the case where the finger position fixing section80eis attached to the operation section50with the screws87has been described, but the finger position fixing section80eis not necessarily attached with screws. The finger rest section82may be fit into and attached to the main body case59or may be attached thereto, for example, by using a rail.

The embodiments of the invention have been described above, and a variety of changes can be made to the embodiments described above to the extent that the changes do not depart from the substance of the invention. For example, variations different from the embodiments described above are as follows.

The above embodiments have been described with reference to the case where the tube group15is formed of three tubes, the supply tube12, the suction tube14, and the cable18, but the tube group15is not necessarily formed of three tubes. The liquid ejection device10does not necessarily have the suction function, and the tube group15may therefore be formed of two tubes, the supply tube12and the cable18. Still instead, the liquid ejection device10may eject a plurality of liquids L, and two or more supply tubes12may therefore be provided. Further, to enhance the suction performance of the liquid ejection device10, two or more suction tubes14may be provided. A liquid ejection device10including an operation section50capable of precise operation can be provided by arrangement of a plurality of tubes having different degrees of rigidity in accordance with the spirit of the invention described above.

In each of the embodiments described above, the configuration in which the piezoelectric element62is used as the pulsed flow applying part60, but the piezoelectric element62is not necessarily used. An ejection mechanism based on a thermal jet method using a laser, a heater, and other components or a bubble jet (registered trademark) method may be used. Further, the pulsed flow applying part60may be disposed in a position external of the operation section50, but the ejection tube54may be disposed in the operation section50. Still further, continuous flow may be ejected as well as pulsed flow.

Since it is conceivable that the tube group15is exchanged in every surgery in consideration of contamination and damage in the surgery or any other situation, the tube group15may be attachable and detachable individually or in the form of a kit to and from the device main body section20and the operation section50. Further, the material and the quality thereof described in the above embodiments are presented by way of example and are not necessarily employed.

The entire disclosure of Japanese Patent Application No. 2015-083118 filed Apr. 15, 2015 is expressly incorporated by reference herein.