ELECTRODE DEVICE FOR BLOCKING OR CONTROLLING NERVES IN BODY

An electrode device for nerve denervation or modulation in vivo includes a main body including a shaft; an electrode unit formed to be drawn out from one end of the shaft and configured to denervate or modulate at least some of nerves on a tube in the body; an electrode guide coupled to the end of the electrode unit and configured to guide the electrode unit to be brought into contact with the tube in the body; an electrode guide driving unit configured to move the electrode guide in forward and backward directions; and an electrode driving unit configured to move the electrode guide in the forward and backward directions in conjunction with the electrode guide driving unit.

TECHNICAL FIELD

The present disclosure relates to an electrode device for nerve denervation or modulation in vivo.

BACKGROUND

A denervation is a surgical procedure intended to control an abnormally overactive autonomic nervous system by damaging specific nerves. For example, a renal denervation can treat hypertension and heart diseases by damaging renal sympathetic nerves directed to the kidney, and a pulmonary denervation can treat lung diseases by damaging parasympathetic nerves directed to the lung.

Nerves usually enclose the outer walls of tubes, such as blood vessels, bronchial tubes, etc., and it may be necessary to enclose the outer walls of tubes to measure signals from the nerves or transmit electrical impulses or various energies to the nerves to damage or destroy the nerves. For example, when a surgical procedure is performed on the renal artery, the main renal artery which is a procedure target has a diameter of from 5 mm to 7 mm, and the accessory renal artery having a diameter of from 1 mm to 2 mm may also be a procedure target. Also, the artery with distributed nerves varies in size from person to person and has different sizes depending on the location.

When the surgical procedure is performed as described above, it is important to delicately locate a component including an electrode to be formed at the end of a catheter so as to enclose the outer wall of the artery. Specifically, in order to effectively denervate or modulate the nerves, the component needs to enclose the outer wall of the artery with distributed nerves in a circumferential direction. Also, it is necessary to reliably and rapidly enclose the artery with the component including the electrode. In particular, it is important to safely and accurately adhere the electrode-formed component to the outer wall of the tube in the body so as not to damage the tube in the body, which can be easily damaged by external stimuli.

DISCLOSURE OF THE INVENTION

Problems to be Solved by the Invention

The present disclosure is conceived to provide an electrode device having a component that guides a plurality of unit elements to enclose the circumference of a tube in the body.

Also, the present disclosure is conceived to provide an electrode device configured to accurately bring a component including an electrode into close contact with an outer wall of the tube in the body without damaging the tube which can be easily damaged by external stimuli.

The problems to be solved by the present disclosure are not limited to the above-described problems. There may be other problems to be solved by the present disclosure.

Means for Solving the Problems

According to an aspect of the present disclosure, an electrode device for nerve denervation or modulation in vivo includes a main body including a shaft; an electrode unit formed to be drawn out from one end of the shaft and configured to denervate or modulate at least some of nerves on a tube in the body; an electrode guide coupled to the end of the electrode unit and configured to guide the electrode unit to be brought into contact with the tube in the body; an electrode guide driving unit configured to move the electrode guide in forward and backward directions; and an electrode driving unit configured to move the electrode guide in the forward and backward directions in conjunction with the electrode guide driving unit. The electrode driving unit includes a tensile force maintaining unit connected to one end of the electrode unit and configured to provide a tensile force to the electrode unit; and a moving unit that moves the tensile force maintaining unit in the forward direction until the electrode guide encloses the circumference of the tube in the body in a state where the moving unit is connected to the tensile force maintaining unit, and then is disconnected from the tensile force maintaining unit. After the tensile force maintaining unit and the moving unit are disconnected from each other, an electrode connection portion connected to one end of the electrode unit moves in the backward direction.

The above-described aspects are provided by way of illustration only and should not be construed as liming the present disclosure. Besides the above-described embodiments, there may be additional embodiments described in the accompanying drawings and the detailed description.

Effects of the Invention

According to any one of the above-described aspects of the present disclosure, an electrode guide is located close to a tube in the body and then gradually brings an electrode unit into close contact with an outer wall of the tube, and, thus, an electrode driving unit after an electrode guide can safely and accurately bring a component including an electrode into close contact with the outer wall of the tube without damaging the tube which can be easily damaged by external stimuli.

BEST MODE FOR CARRYING OUT THE INVENTION

Through the whole document, the term “connected to” or “coupled to” that is used to designate a connection or coupling of one element to another element includes both a case that an element is “directly connected or coupled to” another element and a case that an element is “electronically connected or coupled to” another element via still another element. Further, it is to be understood that the term “comprises or includes” and/or “comprising or including” used in the document means that one or more other components, steps, operation and/or existence or addition of elements are not excluded in addition to the described components, steps, operation and/or elements unless context dictates otherwise and is not intended to preclude the possibility that one or more other features, numbers, steps, operations, components, parts, or combinations thereof may exist or may be added.

Hereinafter, an exemplary embodiment of the present disclosure will be described in detail with reference to the accompanying configuration views or process flowcharts.

FIG.1is a side view of an electrode device according to an embodiment of the present disclosure.FIG.2illustrates a state where an electrode guide illustrated inFIG.1guides and locates an electrode unit to enclose a blood vessel according to an embodiment of the present disclosure.FIG.3AthroughFIG.3Eillustrates an operation process of the electrode guide according to an embodiment of the present disclosure.FIG.4is an exploded perspective view illustrating a portion of joint units illustrated inFIG.2.FIG.5is a cross-sectional view of an electrode guide driving unit located inside a main body illustrated inFIG.1.FIG.6AthroughFIG.6Fillustrates an operation process of an electrode driving unit according to an embodiment of the present disclosure.FIG.7is an example diagram provided to explain the electrode driving unit according to another embodiment of the present disclosure.

Referring toFIG.1, the electrode device100includes the main body110, the electrode unit120and the electrode guide130, the electrode guide driving unit140and the electrode driving unit150disposed inside the main body110.

The main body110may include a shaft111extending in one direction, a grip portion112connected to the shaft111so as to be gripped by an operator, a guide manipulation unit113formed on the grip portion112so as to manipulate an operation of the electrode guide130, and an electrode manipulation unit114formed on the grip portion112so as to manipulate energy transfer to the electrode unit120.

The components for driving and controlling the electrode unit120and the electrode guide130may be located inside the main body110. For example, the electrode guide driving unit140configured to drive and control the electrode guide130and the electrode driving unit150configured to drive and control the electrode unit120may be disposed inside the main body110.

The electrode unit120is formed to be drawn out from one end of the shaft111and configured to denervate or modulate at least part of nerves distributed on a tissue in the body including a tube depending on manipulation by the operator. The electrode unit120is accommodated inside the shaft111and when the electrode device100operates, the electrode unit120can be drawn out by means of the electrode guide130which will be described later.

Referring toFIG.2, the electrode unit120may include a base unit121, an electrode unit122and a sensor unit123. In the electrode device100, an electrode encloses an outer surface of a tube or tube-shaped tissue V in the body and energy can be transferred through the electrode. To this end, the base unit121may be formed as a flexible printed circuit board (PCB).

The electrode unit122may be composed of two electrodes extending parallel to each other on the base unit121on the base unit121. In the present embodiment, the base unit121and the electrode unit122may be configured to extend in a circumferential direction and enclose the tube in the body or the like.

The electrode unit122may be made of a material such as stainless steel or gold, which is harmless to the human body and conducts electricity well, in order to block or denervate or control or modulate the nerves.

Also, the electrode unit122may transfer various types of energy from an energy source generator. For example, the energy may include radio-frequency (RF) energy, electrical energy, laser energy, ultrasonic energy, high-intensity focused ultrasound energy, cryogenic energy and other heat energy.

Also, the electrode unit122may be implemented as a flexible PCB for transferring RF energy, a transducer for transferring ultrasonic energy or a metal electrode for transferring high-voltage energy and thus may transfer energy to damage the nerves.

Further, the sensor unit123may be formed on the base unit121. For example, the sensor unit123may be a thermocouple that measures a temperature by contacting with the tube in the body or the like, and when neurotomy is performed with the electrode device100, the sensor unit123may monitor a temperature of a treatment site. As another example, the sensor unit123may measure signals from the nerves on the tube.

The sensor unit123may be, for example, a thermocouple composed of a pair of copper and constantan.

The electrode guide130functions to bring the electrode unit120into contact with the tube in the body. The electrode guide130is coupled to the electrode unit120and deformed into a wound state to bring the electrode unit120into contact with the tube in the body.

Referring toFIG.2throughFIG.4, the electrode guide130includes a plurality of joint units131. The plurality of joint units131forms a curved winding path P to enclose the circumference of the tube V in the body with the electrode unit120interposed therebetween. The state illustrated inFIG.2,FIG.3CandFIG.3Dmay be a state where the plurality of joint units131is disposed along the curved winding path P.

Referring toFIG.3AthroughFIG.3E, the electrode guide130may further include a tip joint132and a wire133. The tip joint132may support the electrode unit120and may be coupled to the end of the plurality of joint units131connected sequentially to each other.

The tip joint132may be drawn out from one end of the shaft111earlier than the plurality of joint units131. As illustrated inFIG.3D, the tip joint132may be located close to the tube V in the body and may have a tapered shape that gradually decreases in width or thickness toward the end in order to suppress interference with the electrode unit120or maximize the surface enclosing the tube in the body. The end of the electrode unit120may be fastened and fixed to the tip joint132.

The wire133may be formed to sequentially penetrate the plurality of joint units131. Referring toFIG.4, each joint unit131may have a through-hole131cin a longitudinal direction to allow penetration of the wire133.

The end of the wire133sequentially penetrating the through-holes131cmay be coupled and fixed to the tip joint132, and the wire133can slide with respect to each joint unit131in the through-hole131cin the longitudinal direction.

Therefore, the wire133can guide the plurality of joint units131and the tip joint132to be located on the winding path and provide a force of pulling the plurality of joint units131and the tip joint132in a direction to be wound around the tube V.

The wire133may be operated to protrude from one end of the shaft111together with to the plurality of joint units131. Here, the wire133may be designed to protrude less than the plurality of joint units131per unit time and thus can provide a force of pulling the plurality of joint units131along a curved path.

Each join unit131may include hinge units131aand winding support units131b. The hinge units131aare configured for rotatable connection to adjacent joints and may be formed on one or both sides of the joint unit131in the longitudinal direction in which the joint units131are connected parallel to each other.

As illustrated inFIG.4, the hinge unit131amay have a rotation axis in a direction intersecting the longitudinal direction so as to be connected to the hinge unit131aof the adjacent joint unit131. A hinge pin (not illustrated) may be inserted into and fastened to each hinge unit131ain the direction of the rotation axis.

The winding support units131bare configured to support the plurality of joint units131on the winding path and may be formed on one or both sides of the joint unit131in the longitudinal direction to support the adjacent joint unit131.

As illustrated inFIG.2andFIG.4, the winding support unit131bmay be located adjacent to the hinge unit131ain an inward direction of the electrode guide130(in a direction of winding the joint unit131).

For example, the winding support unit131bmay be formed as a surface having a predetermined angle and area and supported by the adjacent winding support unit131bin surface contact with each other, and, thus, a wound shape of the electrode guide130can be maintained.

The winding support unit131band the wire hole131cmay be formed at locations spaced apart from a rotation center of the hinge unit131ain an inward direction toward the tube V in the body.

When the wire133is pulled backwards relative to the electrode guide130(when a length of the wire133drawn out from the shaft111is smaller than that of the joint units131), a tensile force may be applied to the wire133in a direction of winding the electrode guide130. On the other hand, the winding support units131bmay provide a force of supporting the joint units131to each other in a direction of suppressing winding of the electrode guide130. Since the wire133and the winding support units131bform a balanced force in opposite directions, the electrode guide130can be fixed on the winding path.

Further, the electrode guide130may include a first joint group131xand a second joint group131y. That is, the plurality of joint units131may be divided into the first joint group131xand the second joint group131yhaving different lengths.

Due to a difference in length, the first joint group131xmay form a first radius of curvature and the second joint group131ymay form a second radius of curvature greater than the first radius of curvature. As can be seen fromFIG.3D, the joint units having a relatively small length (the first joint group131x) may form a smaller radius of curvature and the joint units having a relatively great length (the second joint group131y) may form a greater radius of curvature.

When the joint units131located close to the tip joint132form a path having a smaller radius of curvature, a path along which the tip joint132enters a space between the tube in the body and the shaft111may be formed as shown inFIG.3D. Also, the electrode guide130including the joint units131may have an overall spiral shape.

Referring toFIG.3AthroughFIG.3E, the electrode guide130is accommodated together with the electrode unit120inside the shaft111and may protrude from one end in a forward direction F while being deformed into the wound state at the time of surgical procedure.

For example, when the plurality of joint units131is sequentially drawn out, the plurality of joint units131may move along the curved winding path due to a difference in displacement from the wire133and thus may overall enclose the tube V.

Further, the electrode guide130is spaced apart from an outer circumferential surface of the tube and the electrode unit120located inside the wound electrode guide130may be in close contact with the outer circumferential surface of the tube V.

The plurality of joint units131may be drawn out from the shaft111by means of the electrode guide driving unit140and wound in a direction to enclose the tube V. Accordingly, a space where the electrode guide130operates can be minimized, and an operation of denervating or modulating nerves can be performed safely and accurately in a narrow space.

Referring toFIG.5, the electrode guide driving unit140may be configured to move the electrode guide130in forward and backward directions, and may include a frame141, a motor unit142, a rod block143, a wire block144and a variable connection unit145.

The frame141may be provided to be fixed inside the main body and may include a guide slot or guide shaft extending in the forward and backward directions.

The motor unit142may be connected to the frame141and may rotate a rotation shaft142arotatably supported by the frame141. For example, the motor unit142may receive electrical energy to rotate the rotation shaft142a.

One end of the rod block143may be connected to the joint unit131. The rod block143may be moved in the forward and backward directions by means of the motor unit142. Specifically, the rod block143may be moved in the forward and backward directions in engagement with the rotation shaft142aextending in the forward and backward directions and having a thread thereon.

The rod block143may include a rod143a, which is located inside the shaft111and extends in one direction (forward and backward directions) and supports the joint units131, and a corrugated component slidably coupled to the guide slot or guide shaft of the frame141.

In addition to the above-described rotation shaft142aand motor unit142, the electrode guide driving unit140according to the present disclosure may be configured to move the rod block143in the forward and backward directions by various linear actuation mechanisms. For example, the electrode guide driving unit140may include a linear actuator of cylinder type including a pneumatic, hydraulic or electric linear actuator, or a piezoelectric or ultrasonic linear actuator.

The wire block144may be formed to support the wire133and moved in the forward and backward directions in conjunction with the rod block143. The wire block144may include a corrugated component slidably inserted into the guide slot or guide shaft and a sliding hole144aslidably accommodating the rotation shaft142a, and may move in the forward and backward directions in parallel to the rod block143

The variable connection unit145may connect the rod block143and the wire block144to each other and vary a distance between the rod block143and the wire block144. To this end, the variable connection unit145may include a rod link145a, a wire link145b, a hinge pin145cand a pin slot145d.

The rod link145aand the wire link145bmay be rotatably connected to the rod block143and the wire block144, respectively. Also, the rod link145aand the wire link145bmay be rotatably connected to each other by the hinge pin145c.

The pin slot145dis formed to slidably accommodate the hinge pin145c. Specifically, the pin slot145dis formed to extend at a predetermined tilt angle with respect to the forward and backward directions. The pin slot145dmay be formed in the frame141.

Meanwhile, the electrode unit120may be drawn out from the shaft111by means of the electrode driving unit150and may be wound in the direction to enclose the tube V by means of the electrode guide130. Specifically, when the electrode unit120moves together with the electrode guide130in the forward direction along the curved winding path and completely drawn out from the shaft111and disposed, the electrode unit120may be gradually brought into close contact with the tube V in the body under the control of the electrode driving unit150. Therefore, in a state where the electrode unit120is stably in contact with the tube V in the body without damaging the tube V in the body, an operation of denervating or modulating nerves can be performed.

Referring toFIG.6A, the electrode driving unit150may be configured to move the electrode unit120in the forward and backward directions in conjunction with the electrode guide driving unit140. The electrode driving unit150may include a tensile force maintaining unit151, a moving unit152, a reducer153, a forward movement rail154, a backward movement rail155, a connection rail156connecting the forward movement rail154and the backward movement rail155, and a second stopper157. Herein, the forward movement rail154and the backward movement rail155may have the same length.

The tensile force maintaining unit151may be connected to one end of the electrode unit120and may provide a tensile force to the electrode unit120. The tensile force maintaining unit151may include a first spring151a, the protrusion151bupwardly protruding from one side, a first stopper151can electrode connection portion151don the other side.

The first spring151amay provide a tensile force to the electrode unit120, and the first stopper151cmay block movement of the protrusion151bwhen the tensile force maintaining unit151moves in the forward direction to generate the tensile force of the first spring151a.

The electrode connection portion151dmay be connected to one side of the electrode unit120and transfer the tensile force of the first spring151ato the electrode unit120. The electrode connection portion151dmay move in the backward direction due to a decrease in tensile force of the first spring151awhen the tensile force maintaining unit151and the moving unit152are disconnected from each other.

The moving unit152may move the tensile force maintaining unit151in the forward direction until the electrode guide130encloses the circumference of the tube V in the body in a state where the moving unit152is connected to the tensile force maintaining unit151, and then may be disconnected from the tensile force maintaining unit151.

The moving unit152may include a connection portion152afor connection to the tensile force maintaining unit151, the pin152b, a support152cand a hinge152d.

The pin152bmay be formed on one side of the connection portion152a, and may move in the forward direction along the forward movement rail154or may move in backward direction along the backward movement rail155. Accordingly, the moving unit152may move in the forward direction together with the tensile force maintaining unit151along the forward movement rail154through the pin152b, and may move in the backward direction along the backward movement rail155after being disconnected from the tensile force maintaining unit151.

The support152cmay be connected to the electrode guide driving unit140. For example, the support152cmay be connected to the wire block144.

The hinge152dis configured to make the connection portion152arotate, and when the pin152bmoves from the forward movement rail154to the connection rail156, the hinge152drotates and the connection portion152amay be disconnected from the tensile force maintaining unit151. Therefore, after the connection portion152ais disconnected from the tensile force maintaining unit151, each of the electrode unit120and the electrode guide130may move.

The reducer153may reduce the tensile force of the first spring151awhen the tensile force maintaining unit151and the moving unit152are disconnected from each other.

Specifically, when the tensile force maintaining unit151and the moving unit152are disconnected from each other, the tensile force of the first spring151ais transferred all at once to the electrode unit120, and, thus, the electrode unit120is brought into close contact with the tube V, which may cause damage to the tube V. Therefore, in the present disclosure, the reducer153gradually reduces the tensile force of the first spring151aso that damage to the tube V can be suppressed.

When the pin152bmoves in the backward direction, the second stopper157may suppress the pin152bnot to move again along the connection rail156. The second stopper157may block the connection rail156when the pin152bis located on the backward movement rail155through the connection rail156.

Hereafter, driving of the electrode unit120by means of the electrode driving unit150will be described with reference toFIG.6AthroughFIG.6D.FIG.6AthroughFIG.6Fillustrate states corresponding to the states illustrated inFIG.3AthroughFIG.3E.

The electrode driving unit150and the electrode guide driving unit140illustrated inFIG.6Amay be in a state right before forward movement starts or right after backward movement ends. Therefore, as illustrated inFIG.3A, the electrode unit120and the electrode guide130may be in a state right before enclosing the circumference of the tube V in the body or right after the electrode unit120and the electrode guide130having enclosed the circumference of the tube V in the body are transitioned to the state before enclosing the tube V. That is, the electrode unit120and the electrode guide130may be in a state right before or right after neurotomy is performed with the electrode device100.

Referring toFIG.6BandFIG.6C, the electrode driving unit150may move in the forward direction along a path provided by the forward movement rail154together with the electrode guide driving unit140moving in the forward direction. As illustrated inFIG.3BandFIG.3C, due to forward movement of the electrode driving unit150and the electrode guide driving unit140, the electrode unit120and the electrode guide130may be drawn out from the shaft111in the forward direction F and wound to enclose the circumference of the tube V in the body.

Specifically, when the electrode guide driving unit140is moved in the forward direction by driving of the motor unit142, the tensile force maintaining unit151is also moved in the forward direction through the moving unit152.

That is, as the electrode guide driving unit140moves in the forward direction, the pin152bof the moving unit152connected to the electrode guide driving unit140may move in the forward direction along the forward movement rail154. Here, the electrode guide130is drawn out from the shaft111in the forward direction F and the tensile force maintaining unit151connected to the moving unit152moves in the forward direction, and, thus, the electrode unit120of which one end is connected to the electrode connection portion151dmay also be drawn out from the shaft111.

Here, the first stopper151cof the tensile force maintaining unit151may block movement of the protrusion151bwhen the tensile force maintaining unit151moves in the forward direction. Referring toFIG.6B, forward movement of the protrusion151bon one side of the tensile force maintaining unit151, which moves together with the electrode guide driving unit140, is blocked by the first stopper151c, but the electrode connection portion151don the other side of the tensile force maintaining unit151can move in the forward direction together with the moving unit152.

As illustrated inFIG.6C, forward movement of the protrusion151bof the tensile force maintaining unit151is blocked by the first stopper151c, but the electrode connection portion151dof the tensile force maintaining unit151moves in the forward direction together with the moving unit152, and, thus, a length of the first spring151amay increase (D1→D2) and a tensile force may be generated.

Referring toFIG.6C, when the electrode guide driving unit140and the pin152bof the moving unit152move to the end of the path provided by the forward movement rail154, the electrode unit120and the electrode guide130may be together wound to be close to the tube V in the body as illustrated inFIG.3C. Here, the electrode guide130may be in a state where the plurality of joint units131is completely drawn out along the curved winding path.

Referring toFIG.6D, when forward movement of the electrode guide driving unit140is completed, the pin152bof the moving unit152moves along the connection rail156and the hinge152drotates. Thus, the connection portion152aand the tensile force maintaining unit151may be disconnected from each other.

After the tensile force maintaining unit151is disconnected from the moving unit152, the electrode connection portion151dconnected to one end of the electrode unit120may move in the backward direction. The electrode connection portion151dmay move in the backward direction due to a decrease in tensile force of the first spring151a. When the electrode connection portion151dmoves in the backward direction, the electrode unit120may be brought into contact with the tube V in the body as illustrated inFIG.3D.

Specifically, as illustrated inFIG.6D, in a state where the protrusion151bof the tensile force maintaining unit151is stopped by the first stopper151c, only the electrode connection portion151dof the tensile force maintaining unit151moves in the backward direction at the time of disconnection from the moving unit152. Therefore, the length of the first spring151amay decrease to a predetermined length (D2→D3), and a tensile force is provided to the electrode unit120so that the electrode unit120can be brought into close contact with the tube V in the body. That is, when the tensile force maintaining unit151and the moving unit152are disconnected from each other, only the electrode connection portion151dof the tensile force maintaining unit151moves in the backward direction, and, thus, a distance between one side of the electrode connection portion151dand one side of the electrode guide driving unit140may increase to a predetermined distance (d1→d2).

The electrode unit120in contact with the tube V in the body may transfer energy for damaging nerves, and, thus, neurotomy can be performed.

Here, when the tensile force maintaining unit151and the moving unit152are disconnected from each other, the electrode driving unit150may gradually reduce the tensile force of the first spring151aby means of the reducer153. That is, the length of the first spring151amay be gradually decreased to a predetermined length (D2→D3) by means of the reducer153. Therefore, as the electrode connection portion151dgradually moves in the backward direction, the electrode unit120may be gradually brought into close contact with the tube V in the body. Thus, it is possible to suppress damage to the tube V in the body when the electrode unit120is in close contact with the tube V in the body during neurotomy.

Then, referring toFIG.6EandFIG.6F, after the tensile force maintaining unit151and the moving unit152are disconnected from each other, the electrode driving unit150may move the moving unit152in the backward direction. Since the moving unit152and the electrode guide driving unit140move in the backward direction along the backward movement rail155, it is possible to make the electrode guide130deviate from the circumference of the tube V in the body as illustrated inFIG.3E.

Specifically, as the electrode guide driving unit140moves in the backward direction, the pin152bof the moving unit152connected to the electrode guide driving unit140may move in the backward direction along the backward movement rail155. Thus, the other side of the connection portion152ameets the electrode connection portion151dof the tensile force maintaining unit151that has moved in the backward direction and thus the other side of the connection portion152amay cause the tensile force maintaining unit151to move in the backward direction.

As illustrated inFIG.6E, as the electrode connection portion151dof the tensile force maintaining unit151moves in the backward direction together with the moving unit152, the length of the first spring151amay decrease to a predetermined length (D3→D1) and all the tensile force generated in the first spring151amay be removed.

When the pin152bmoves in the backward direction, the electrode driving unit150blocks the connection rail156by means of the second stopper157to suppress the pin152bnot to move again along the connection rail156. For example, the second stopper157may include a spring that compresses the second stopper157in order for the pin152bto move along the connection rail156and returns the second stopper157back to its original state when the pin152bis located on the backward movement rail155.

As the electrode guide driving unit140and the electrode driving unit150move in the backward direction, the electrode unit120and the electrode guide130may move in a backward direction B toward the shaft111as illustrated inFIG.3E.

When backward movement of the electrode guide driving unit140and the electrode driving unit150is completed, the pin152bof the moving unit152may be located on the forward movement rail154, i.e., in a standby state as illustrated inFIG.6A. Here, the electrode unit120and the electrode guide130may also be in a standby state before protruding from the shaft111as illustrated inFIG.3A.

Referring toFIG.7, the electrode driving unit150according to another embodiment may further include a second spring158that connects the support152cand the connection portion152a. The electrode driving unit150may suppress the pin152bnot to move again along the connection rail156by using the second spring158when the pin152bmoves in the backward direction.

Therefore, the electrode driving unit150may suppress the pin152bnot to move again along the connection rail156when the pin152bmoves in the backward direction by using the second spring158connecting the support152cand the connection portion152awithout a stopper that blocks the connection rail156.

The above description of the present disclosure is provided for the purpose of illustration, and it would be understood by a person with ordinary skill in the art that various changes and modifications may be made without changing technical conception and essential features of the present disclosure. Thus, it is clear that the above-described embodiments are illustrative in all aspects and do not limit the present disclosure. For example, each component described as a single type may be implemented in a dispersed form, and likewise components described as distributed may also be implemented in a combined form.