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Description  |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a treating instrument inserted into, for
example, a body cavity of a patient for medical treatment or into a given
cavity of a pipe or duct for treatment or repair.
2. Description of the Related Art
For example, Published Unexamined Japanese Patent Application 56-112221 and
Published Unexamined Japanese Utility Model 62-164009 disclose biopsying
forceps as one form of a treating instrument for an endoscope. In the
forceps disclosed, a pair of openable/closable biopsying cups are mounted
on the distal end of a lengthy insertion sheath. The cups are connected to
the forward end of operation wire means inserted through the insertion
sheath.
The operation wire means is connected at a base end to an operation
mechanism on the operator's side of the forceps. In the forceps, biopsying
cups are opened and closed by the operation of an operation mechanism on
the operator-end side and hence a remote-controlled push/pull operation.
In the conventional treating instrument for an endoscope, an operation
force of the operation mechanism is transmitted by operating wire means to
the biopsying cups on a distal end of the lengthy sheath. It is necessary
to use an operation wire means of a proper thickness enough strong to
transmit an operative mechanical drive force to the cups. In the
conventional treating instrument for an endoscope, however, there is a
limit on the diameter narrowing of the insertion sheath, failing to reduce
the diameter of the insertion sheath to a minimum possible extent.
Further, a mechanism is required which can transmit a drive force which
arises from the actuated operation wire means, as a mechanical motion, to
the treating member, such as the biopsying forceps. This involves a
complex structure on the distal end of the insertion sheath.
Since the cups are opened or closed by the manually-controlled operation of
the operation wire means, such opening/closing operation appreciably
differ from operator to operator. It is thus difficult to accurately open
and close the cups.
Further, there is a possibility that, when the insertion section of the
treating instrument is to be inserted into a meandering duct or tract, an
operation force involved upon the operation of the operation wire means
will be partially absorbed, failing to accurately transmit such operation
force to the distal end of the insertion section. It is thus difficult to
accurately open and close the cups in a desired fashion.
SUMMARY OF THE INVENTION
It is accordingly the object of the present invention to provide a treating
instrument which can make a drive mechanism of a treating unit on the
distal-end side of an endoscope simple and compact and can narrow the
diameter of the insertion sheath and also operate the treating unit
accurately.
In order to achieve the object of the present invention, there is provided
a treating instrument comprising an insertion section to be inserted into
either one of a human body cavity for medical treatment and an industrial
pipe and having a distal end and an operator-side end; a treating unit
connected to the distal end of the insertion section; an operation member
provided at the treating section to be movable between a standby position
and an operative position so that a target region in a given cavity can be
treated, an actuator mounted on the distal end of the insertion section
and generating a drive force of the operation member; drive means for
driving the actuator; grip means connected to the operator-side end of the
insertion section; and means, provided on the grip means, for outputting a
control signal for controlling an operation of the drive means.
According to the present invention, the treating unit can be driven by an
actuator on the distal end of the insertion section, obviating the
necessity of providing an operation wire means of a thickness enough great
to transmit a drive mechanical operation force. As a result, the drive
mechanism of the treating member on the distal end of the sheath can be
made simple and compact and it is also possible to narrow the diameter of
the insertion section and to accurately operate the treating unit.
Additional objects and advantages of the invention will be set forth in the
description which follows, and in part will be obvious from the
description, or may be learned by practice of the invention. The objects
and advantages of the invention may be realized and obtained by means of
the instrumentalities and combinations particularly pointed out in the
appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part
of the specification, illustrate presently preferred embodiments of the
invention, and together with the general description given above and the
detailed description of the preferred embodiments given below, serve to
explain the principles of the invention.
FIG. 1 is a side view generally showing biopsying forceps according to a
first embodiment of the present invention;
FIG. 2A is a longitudinal cross-sectional view showing a movable member of
the forceps in FIG. 1 and FIG. 2B is a longitudinal cross-sectional view
showing the movable member in an advanced state;
FIG. 3A is a longitudinal cross-sectional view showing a major portion of
an operation means for driving a pair of cups and FIG. 3B is a
longitudinal cross-sectional view showing a major portion of the pair of
cups in an opened state;
FIG. 4A is a longitudinal cross-sectional view showing a major portion of a
forward end section of biopsying forceps according to a second embodiment
of the present embodiment and FIG. 4B is a longitudinal cross-sectional
view showing the major portion of a pair of cups in an opened state;
FIG. 5A is a longitudinal cross-sectional view showing an intracavity stone
crushing instrument according to a third embodiment of the present
invention and FIG. 5B is a longitudinal cross-sectional view showing a
variant of the third embodiment;
FIG. 6 is a perspective view showing a microarticulated unit;
FIG. 7A is a plan view showing a mask for the macroarticulated unit, FIG.
7B is a longitudinal cross-sectional view showing the mask covered on the
outer periphery of a thin-film tube, FIG. 7C is a longitudinal
cross-sectional view for explaining an etched state of the thin-film tube
and FIG. 7D is a longitudinal cross-sectional view showing a
microarticulated unit;
FIG. 8A is a diagrammatic view showing, in an operative state, a surgical
operation microrobot according to a fourth embodiment of the present
invention and FIG. 8B is a diagrammatic view showing a state in which a
bypass operation is done in the coronary artery of the heart;
FIG. 9 is an expanded view diagrammatically showing a major portion of a
microrobot for surgery;
FIG. 10A is a perspective view showing a major portion of a gripper for a
microrobot and FIG. 10B is a side view of the gripper;
FIG. 11A is a perspective view showing a biopsying forceps type treating
unit for a microrobot and FIG. 11B is a perspective view showing a scissor
forceps type treating unit;
FIG. 12A is a diagrammatic view showing, in an operative state, a treating
instrument according to a fifth embodiment of the present invention, FIG.
12B is a perspective view showing a state in which a microgripper is
projected out of an insertion channel of a treating instrument for an
endoscope, FIG. 12C is a perspective view showing a microgripper and FIG.
12D is a diagrammatic view showing a linear type ultrasonic motor;
FIG. 13 is a perspective view showing a variant of the gripper;
FIG. 14A is a perspective view showing a storage state of basket wires at a
basket type treating unit and FIG. 14B is a perspective view showing an
extended state of basket wires;
FIG. 15A is a perspective view showing a storage state of a high-frequency
surgical knife type treating unit and FIG. 15B is a perspective view
showing an extended state of a high-frequency surgical knife type treating
unit;
FIG. 16 is a diagrammatic view showing a degrees-of-multifreedom tubular
manipulator according to a sixth embodiment of the present invention;
FIG. 17A is a diagrammatic view showing a microgripper according to a
seventh embodiment of the present invention, FIG. 17B is a perspective
view of the microgripper, FIG. 17C is a front view of the microgripper and
FIG. 17D is a diagrammatic view for explaining the operation of an
actuator in the microgripper of FIG. 17A;
FIG. 18 is a diagrammatic view showing a major part of an eighth embodiment
of the present invention;
FIG. 19 is a diagrammatic view for explaining the operation of an actuator
in the eighth embodiment;
FIG. 20A is a diagrammatic view showing a microgripper according to a ninth
embodiment of the pre sent invention and FIG. 20B is a front view of the
microgripper in FIG. 20A;
FIG. 21 is a diagrammatic view for explaining the operation of an actuator
of FIG. 20B;
FIG. 22 is a perspective view showing a major part in a tenth embodiment of
the present invention;
FIG. 23 is a perspective view showing a major part in an eleventh
embodiment of the present invention;
FIG. 24 is an exploded view of the major part shown in FIG. 23;
FIG. 25 is a perspective view showing a major section in a twelfth
embodiment of the present invention;
FIG. 26 is a side view showing the major section in the embodiment of FIG.
25; and
FIG. 27 is a perspective view showing a major section in a thirteenth
embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 to 4B show a first embodiment of the present invention. FIG. 1
shows biopsying forceps 1 as one form of a treating instrument for an
endoscope. A flexible sheath 2 is provided on an insertion section of the
biopsying forceps and comprised of a closely-turned coil.
A forceps (treating) unit 3 is provided at a distal end section of the
sheath 2 and a grip means 4 is mounted on a base end of the sheath 2.
A distal tip section 5 of a bottomed-cylindrical configuration is provided
on the forceps section 3. The bottom area of the distal tip section 5 is
fixed to the distal-end side of the sheath 2.
A movable member 6 is inserted in the cylinder of the distal tip section 5
and movable in an axial direction of the sheath 2. Splined grooves 7a are
provided on the outer periphery of the movable member 6 and extend along
the axial direction of the sheath 2 as shown in FIG. 2A.
Splined grooves are provided in the inner wall of the distal tip section to
engage with the splined grooves 7a of the movable member 6. For this
reason, the movable member 6 is held movable only in the axial direction
of the sheath 2, not rotatable relative to the distal end section.
An operating means is provided at the movable member 6 as shown in FIG. 3A.
The movable member 6 has a recess 7 at a base end portion and a slitted
section 8 at a forward end portion.
A pair of cups 9, 9 are provided as an operation member with their bases
9a, 9a pivotally mounted by a pivotal pin 11 within the slitted section 8
of the forceps unit. A pair of links 12, 12 are connected at one end to
the bases 9a, 9a of the cups 9, 9 and at the other end to the forward end
of a rod-like metal drive member 13 serving as an actuator for opening and
closing the cups. The pair of links 12, 12 are pivoted by a common pivotal
pin 14 at those other ends of the respective links 12, 12. Thus a
pantograph mechanism is provided by the bases 9a, 9a of the cups 9, 9 and
links 12, 12 to enable the pair of cups 9, 9 to be opened or closed.
The drive member 13 is secured at the base end to the bottom wall of the
recess 7 of the movable member 6. A heat generating coil 15 is turned
around the outer periphery of the drive member 13 and connected to a power
source 17, for example, in the grip means 4 through a lead wire 16
extending in the sheath 2. An operation switch 18 is provided in the grip
means 4 to control the supply of electric current to the heat generation
coil 15.
With the heat generating coil 15 in a non-conductive state, the drive
member 13 is held in a normal state (a thermally not expanded state) where
the cups 9, 9 are held in a closed state as shown in FIG. 3A.
With the heat generating coil 15 in a conductive state, the drive member 13
is thermally expanded by heat which originates from the heat generating
coil 15. Through the thermal expansion of the drive member 13, the
aforementioned pantograph mechanism is operated as shown in FIG. 3B to
allow the pair of cups 9, 9 to be opened.
As a metal material for the drive member 13, various metals, such as, iron
and copper, can be employed, but it is better to employ a material of high
thermal expansion. It may be possible to employ a two-directional shape
memory alloy.
In that recess 19 of the distal tip section 5 where the base portion of the
movable member 6 is fitted, bellows 21 are located, as an actuator,
relative to the base end of the movable member 6 as shown in FIG. 2A so
that the bellows may be extended and contracted in the axial direction of
the sheath 2 to enable the position of the cups to be moved. The bellows
21 are made up of a metal thin film and have an external diameter as small
as, for example, about a few millimeters.
The forward end of the bellows 21 is secured to the base end of the movable
member 6. The base end of the bellows 21 is fixed to the bottom wall of
the recess 19 of the distal tip section 5. A low boiling point liquid,
such as liquid paraffin or flon, is sealed in the bellows 21 in a hermetic
fashion.
Further, the bellows 21 are formed using an electrodeposition plating
method. That is, a mandrel is initially prepared from aluminum or plastics
so as to conform to a configuration of bellows to be formed. Then a thin
film, such as nickel, copper, gold or silver, is formed as a plated film
on the outer surface of the mandrel and then the mandrel per se is
dissolved, thus leaving the plated thin film as bellows. In this way, it
is possible to form bellows set out above.
According to this method, the bellows can readily be made smaller in
diameter and, for example, as thin as about a few tens of .mu.m and as
small as about 1 mm to a few millimeters in outer diameter.
A heat generating coil 22 is buried in the surrounding wall of the recess
19 of the distal tip section 5. It is to be noted that the heat generating
coil 22 may be arranged on the inner wall surface of the recess of the
distal tip section 5.
The heat generating coil 22 is connected to the power source 24 in the grip
means 4 through the lead wire 23 extending in the sheath 2. An operation
switch 25 is provided in the grip means 4 to control the supply of
electric current to the heating coil 22.
The power sources 24 and 15 of the heat generating coils 22 and 17,
respectively, are comprised of, for example, a battery unit, but an
external power source may be used instead which is connected through a
power source cord leading to the grip means 4 side.
Operating the biopsying forceps 1 will be explained in detail below.
The sheath 2, that is, the insertion section of the forceps 1, is inserted
into a body cavity of a human subject through an insertion channel which
has initially been inserted there and through which a treating instrument
for an endoscope is inserted. At this time, the operation switches 18 and
25 are placed in a non-conductive state and hence no electric current is
carried through the heat generating coils 15 and 22. That is, heat is not
generated at the respective heat generating coils 15 and 22 and the
forceps unit 3 are held in the states shown in FIGS. 2A and 3A where the
cups 9, 9 are closed and hence the movable member 6 is contracted in the
recess 19 of the distal tip section 5.
For the biopsy to be done in the body cavity of the human subject, the
forceps unit 3 are advanced with the operation switch 25 of the grip means
4 ON and hence the heat generating coil 22 in the conductive state.
The heat generating coil 22 is heated, expanding the liquid paraffin in the
bellows 21 through vaporization and hence extending the bellows 21 in the
axial direction. As a result, the cup-mount movable member 6 is pushed out
and advanced as shown in FIG. 2B.
It is possible to adjust an amount of advance of the movable member 6 by
controlling a power energy carried through the heat generating coil 22 and
hence controlling the vaporization of the liquid paraffin and amount of
expansion.
Opening and closing the cups 9, 9 will be explained below.
With the operation switch 18 of the grip means 4 ON, heat is generated at
the heat generating coil 15 around the drive member 13. Upon the heat
generation of the heat generating coil 15 and heating of the drive member
13 thereby, the drive member 13 is expanded in the axial direction as
shown in FIG. 3B and the pair of cups 9, 9 are opened through the
aforementioned pantograph mechanism.
With the operation switch 18 OFF, no electric current is carried through
the heat generating coil 15 around the drive member 13, allowing the drive
member 13 to be heat-dissipated and hence contracting the bellows back to
its original position. Through this contraction action, the pair of cups
9, 9 are closed as shown in FIG. 3A.
Since the metal drive member 13 is provided on the distal end of the sheath
2 of the forceps 1 and the pair of cups 9, 9 of the forceps 1 are opened
through the pantograph mechanism in accordance with the thermal expansion
of the drive member 13, it is not necessary to provide an operation wire
enough thick to transmit a mechanical operation force through the sheath
2. It is thus possible to narrow the diameter of the sheath 2, that is,
the insertion section of the forceps 1, unlike the conventional
counterpart.
Further, since the cups 9, 9 of the forceps 1 are opened or closed in
accordance with the heat expansion of the metal drive member 13 on the
distal end of the sheath 2, it is possible to more accurately open and
close the forceps than in the conventional structure and to do so without
the risk of an operation wife's drive force being partially absorbed
partway upon the opening or closing of the pair of cups 9, 9 in the case
where the sheath 2 of the forceps 1 is inserted in a meandering passage
involved.
As the liquid paraffin-sealed bellows 21 are expanded due to the passage of
electric current through the heat generating coil 22 in the distal tip
section 5 and the vaporization of the liquid paraffin, that is, the
movable member 6 is moved in the axial direction of the sheath 2, it is
readily possible to perform the positional adjustment of the cups 9, 9 in
the axial direction of the sheath.
Further, since the amount of advance of the movable member 6 can be
adjusted by controlling an amount of electric energy passing through the
heat generating coil 22 and hence the vaporization and expansion of the
liquid paraffin, it can be accurately carried out as compared with the
case where the amount of operation by the operation wire can be adjusted
by a manual operation.
FIGS. 4A and 4B show a second embodiment of the present invention. This
embodiment is different from the previous embodiment in that a different
actuator is used in the biopsying forceps 1, that is, a cylinder 31 is
provided relative to the base portion of a movable member 6 in the forceps
unit 3 of the biopsying forceps 1.
A piston 32 is arranged in the cylinder 31 to be slidable in the axial
direction of the cylinder. A piston rod 33 is connected at one end to the
piston 32 and the other end of the piston rod hermetically extends past
the forward end wall of the cylinder 31 into a slitted section 8 of the
movable member 6. Links 12, 12 of a pantograph mechanism are pivoted by a
common pin 14 on the extending end portion of the piston rod 33.
The cups 9, 9 are opened or closed when the piston 32 is moved in
corresponding directions.
A low boiling point liquid 34, such as flon or liquid paraffin, is
hermetically sealed in a front-side space of the cylinder 31 as defined by
the piston 32. A coil spring 35 is provided in a back-side space of the
cylinder 31 defined by the piston 32 such that it is urged in a forward
direction.
A heat generating coil 36 is embedded in the peripheral wall of the
cylinder 31 and connected to, for example, a power source 17 in the grip
means 4 by a lead wire 16 which is arranged in the sheath 2. An operation
switch 18 is provided in the grip means 4 to allow electric current to be
carried through the heating means. The power source 17 is comprised of a
battery unit, but may be an external power source connected to the grip
means side through a power source cord.
A cooling means, such as a Peltier element 38, is located on the back wall
side of the cylinder 31. The Peltier element 38 is employed upon the
liquefaction of the liquid paraffin 34. When electric current is carried
through the heat generating coil 36, the Peltier element 38 is not
operated. The Peltier element 38 is connected to the operator-side control
device via lead wires 39.
The operation of the forceps 1 will be explained below. Since the same
operation as set out above in conjunction with the first embodiment is
done except for the operation of cups 9, 9, explanation will be limited
principally to opening and closing the cups 9, 9.
When the cups 9, 9 are to be closed, the operation switch 18 of the grip
means 4 is turned ON as shown in FIG. 4A to allow electric current to be
carried through the heat generating coil 36.
Heat is generated at the heat generating coil 36 to cause the liquid
paraffin 34 in the front-side space in the cylinder 31 to be expanded
through vaporization. The piston 32 is pushed backward by the expanded
liquid paraffin against the urging force of the coil spring 35. Through
the backward movement of the piston 32, the piston rod 33 is moved back to
a right-side limit position in FIG. 4A, closing the cups 9, 9 through the
pantagraph mechanism.
When the cups 9, 9 are to be opened, the operation switch 18 is turned OFF,
causing the supply of the heat generating coil 36 to be stopped. By so
doing, the liquid paraffin 34 in the forward-end space in the cylinder 31
emits heat spontaneously at which time the liquid paraffin 34 is liquefied
more effectively through a cooling process when the Peltier element 38 is
operated.
In this case, the volume of the liquid paraffin 34 is reduced and hence the
piston 32 is advanced as shown in FIG. 4B under a combined force of a
suction caused by the reduced volume of the liquid paraffin and an urging
force of the coil spring 35.
Through the advance of the piston 32, the piston rod 33 is moved to a
left-side limit position as shown in FIG. 4B, opening the cups 9, 9
through the pantograph mechanism.
By the movement of the piston 32 in the cylinder 31 provided on the distal
end of the sheath 2 of the forceps 1 thus arranged, the cups 9, 9 are
opened and closed, thus obtaining a diameter-reduced insertion section of
the forceps 1 as in the case of the preceding embodiment and an accuracy
with which the cups 9, 9 are operated.
FIG. 5A shows a third embodiment of the present invention. The third
embodiment is employed as an intracavity stone-crushing instrument.
The base end of a bottomed-cylindrical connector 42 is connected to the
distal end of a flexible sheath 41 which is comprised of an insertion
section. An internally threaded section 42a is provided at the base end
portion of the connector so that it can be threaded over an externally
threaded section provided on the distal end portion of the flexible sheath
41. The connector 42 is detachably mounted on the distal end portion of
the flexible sheath 41 through these internally and externally threaded
sections.
A back-end section of a cylinder 43 is fitted over the forward end section
of the connector 42. A reduced-diameter section 43a is provided, as an
internal diameter section, on the forward-end side and an
enlarged-diameter section 43b is provided, as an internal diameter
section, on the back-end side of the cylinder 43. A piston 44 is disposed
in the enlarged-diameter section 43b of the cylinder 43 such that it is
slidably moved back and forth in the axial direction of the cylinder.
A treating rod 45 is provided on the front-end face of the piston 44 such
that it can be extended outwardly or contracted inwardly via a forward
open end 43c provided at the center face wall of the forward end portion
of the cylinder 43.
A coil spring 47 is provided in the cylinder 43 such that it is wound
around the outer periphery of the treating rod 45. One end of the coil
spring 47 is inserted in the reduced-diameter section 43a of the cylinder
43 and the other end of the coil spring is stopped on the forward-end face
of the piston 44. The piston 44 is pressed toward the connector 42 side by
a spring force of the coil spring 47.
A liquid paraffin 34 of such a type as set out above is hermetically sealed
in the base portion of the connector 42. Discharge electrodes 48a, 48b are
provided at the base portion of the connector 42 to face the liquid
paraffin 34 in the base portion of the connector 42.
Lead wires 49a, 49b connected to the corresponding discharge electrodes
48a, 48b lead to the operator's side through the flexible sheath 41 and to
a power source unit 50. A switch 51 is provided in the power source unit
50 to supply voltage to the discharge electrodes 48a, 48b.
The operation of the stone-crushing instrument will be explained below.
Through an instrument insertion channel of the flexible sheath 41 of the
endoscope, the stone-crushing instrument is inserted into a body cavity of
a human being where a stone is formed. The forward end portion of the
cylinder 43 is abutted against the stone in the body cavity of the human
being.
The liquid paraffin 34 in the connector 42, being in a liquefied state,
occupies a small volume and, therefore, the piston 44 is held to a
right-side limit position where it abuts against an inner end of the
connector 42 under an influence of the coil spring 47 as shown in FIG. 5A.
At this time, the position of the forward end face of the treating rod 45
is held flush with the forward face of the cylinder 43.
By operating the operation switch 51 of the operator-side power source unit
50, a discharge occurs across the electrodes 48a and 48b, causing the
liquid paraffin 34 to be instantly expanded. The piston 44 is advanced
leftward (FIG. 5A) under an expansion pressure of the liquid paraffin 34
and the forward end of the treating rod 45 is extended out of the forward
open end 43c of the cylinder 43 whereby a stone in the body cavity of the
human being is crushed.
Thereafter the discharge is stopped and the liquid paraffin 34 is liquefied
so that it is decreased in its volume. In this case, the piston 44 is
returned, under the influence of the coil spring 47, back to an | | |
