Surgical needle abstract
An apparatus for connecting a thread wound on a bobbin to a surgical
needle including feeding rollers for unwinding the thread from the
bobbin, a tube-like chuck for selectively fix the thread thereto,
a guide for guiding the front end of the thread, a feeding device
for supporting the needle such that a hole formed in a rear end
face of the needle is faced to the front end of the thread, and
a clamping device having pushing rods for pressing the rear end
of the needle to clamp the thread in the hole. By moving the needle
to the guide, the front end of the thread is inserted into the hole
of the needle, and then the clamping device is driven to press the
rear end of the needle so that the thread is clamped in the hole.
Then, the thread is unwound from the bobbin by a desired length
by moving the feeding device away from the guide, and finally the
thread is cut along an inclined line.
Surgical needle claims
What is claimed is:
1. An apparatus for automatically connecting a surgical thread
to a surgical needle having a hole formed in an end face of a rear
end thereof, comprising
a means for feeding the surgical needle into a given position;
a means for supplying the surgical thread;
a means for guiding a front end of the surgical thread into a given
position at which the front end of surgical thread is faced to an
opening of the hole formed in the end face of the rear end of the
surgical needle;
a means for inserting the front end of the surgical thread into
the hole of the surgical needle;
a means for pressing the rear end of the surgical needle to clamp
the front end of the surgical thread in the hole of the rear end
of the surgical needle; and
a means for cutting the surgical thread at a given point to form
the surgical needle having the surgical thread of a given length
connected to the rear end thereof.
2. An apparatus according to claim 1 wherein said means for inserting
the front end of the surgical thread into the hole of the surgical
needle comprises a tube-like chuck which selectively fixes the thread
thereto and is movable in a longitudinal direction of the thread.
3. An apparatus according to claim 1 further comprising a heating
means for correcting the curved thread into the straight thread.
4. An apparatus according to claim 1 further comprising a means
for sterilizing the thread supplied from the thread supplying means.
5. An apparatus according to claim 1 wherein said cutting means
is constructed such that the thread is cut along a line which is
inclined with respect to the thread.
6. An apparatus according to claim 1 further comprising a means
for confirming whether the thread has been firmly connected to the
needle or not by applying a tension to the thread.
7. An apparatus according to claim 1 wherein said needle feeding
means is arranged movably in a longitudinal direction, and the apparatus
further comprises a means provided between the needle feeding means
and the thread guiding means and unwinding the thread from the thread
supplying means by a desired length.
8. An apparatus according to claim 7 wherein said unwinding means
comprises a first set of rollers arranged on one side of the thread
and a second set of rollers arranged on the other side of the thread
and movable in a direction perpendicular to the longitudinal direction
of the thread between said first set of rollers.
9. An apparatus according to claim 9 further comprising a means
arrange between the thread supplying means and the guiding means
and applying selectively the brake force to the thread.
10. An apparatus according to claim 1 further comprising a means
for monitoring the positions of the hole of the needle and thread
prior to insertion of the thread into the hole to derive a deviation
signal representing a deviation between the thread and the hole
of the needle, and a means for adjusting the relative position between
the thread and the hole of the needle in accordance with said deviation
signal such that the thread is aligned with the hole of the needle.
11. An apparatus according to claim 10 wherein said monitoring
means comprises two television cameras for picking up images of
the front end of the thread and the rear end of the needle from
different directions.
Surgical needle description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an automatic apparatus for connecting
a thread to a surgical needle by inserting a front end of the thread
into a hole formed in a rear end of the needle and then pressing
the rear end of the needle to clamp the thread in the hole of the
needle.
2. Related Art Statement
In the surgical operation, there have been widely used surgical
needles having threads previously connected to the needles in order
to connect parts of a patient body. There are prepared a quite large
kinds of the surgical needles, and some of them have very small
diameters such as 1 mm or less. It should be noted that threads
to be connected to such thin needles have also very small diameters.
There have been developed various methods for connecting the threads
to the surgical needles, and in the view point of the facileness
in use, a surgical needle having a thread clamped in a hole formed
in the rear end of needle has been preferably used. FIG. 1 illustrates
such a surgical needle. In case of connecting a thread S to a surgical
needle N, a front end of thread is manually inserted into a hole
Nb formed in an end face of a rear end Na and then the rear end
Na of the needle is pressed with the aid of a clamping machine to
clamp the front end of thread S in the hole Nb. During this manual
operation, an operator watches the thread S and needle N under a
microscope. It is apparent that this connecting method requires
an experience of labors and further the efficiency of the work is
very low. Therefore, the manufacturing cost of the surgical needle
is liable to be increased and possibility of occurrence of unusable
needles in large. Moreover, since the operation has to be effected
by inspecting the front end of thread S and the rear end Na of needle
N under the microscope or magnifier, the eyes of the workers might
be fatigued to a large extent.
SUMMARY OF THE INVENTION
The present invention has for its object to provide a novel and
useful apparatus for automatically connecting a surgical thread
to a surgical needle by means of which the thread can be coupled
with the rear end of needle in an efficient and reliable manner.
It is another object of the invention to provide an apparatus for
automatically connecting a surgical thread to a rear end of surgical
needle in which a length of the thread can be determined at will.
According to the invention, an apparatus for automatically connecting
a surgical thread to a surgical needle having a hole formed in an
end face of a rear end thereof, comprises
a means for feeding the surgical needle into a given position;
a means for supplying the surgical thread;
a means for guiding a front end of the surgical thread into a given
position at which the front end of surgical thread is faced to an
opening of the hole formed in the end face of the rear end of the
surgical needle;
a means for inserting the front end of the surgical thread into
the hole of the surgical needle;
a means for pressing the rear end of the surgical needle to clamp
the front end of the surgical thread in the hole of the rear end
of the surgical needle; and
a means for cutting the surgical thread at a given point to form
the surgical needle having the surgical thread of given length connected
to the rear end thereof.
In a preferable embodiment of the apparatus according to the present
invention, the surgical thread is wound on a supply reel and is
unwound therefrom and there is provided a heating means for heating
the thread unwound from the reel to correct a curved shape of the
thread into a straight shape.
In another preferable embodiment of the apparatus according to
the invention, there are provided a means for pulling the thread
after the thread is secured to the needle and a means for confirming
whether the thread has been firmly connected to the needle or not.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view showing the surgical needle having the thread
connected thereto;
FIG. 2 is a schematic view illustrating a first embodiment of the
apparatus according to the invention;
FIG. 3 is a schematic view depicting the operation for inserting
the thread into the hole of the needle;
FIG. 4 is a cross sectional view showing the clamped condition;
FIG. 5 is a cross sectional view illustrating a modification of
the guide shown in FIG. 2;
FIG. 6 is a perspective view depicting a centering device according
to the invention;
FIG. 7 is a schematic view showing a second embodiment of the apparatus
according to the invention;
FIG. 8 is a side view illustrating the clamping device shown in
FIG. 7; and
FIG. 9 is a block diagram depicting the monitoring system.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 2 is a schematic view showing a first embodiment of the apparatus
according to the invention. In FIG. 2 a reference numeral 1 denotes
a clamping device having four pushing rods 1a, 1b, 1c and 1d (in
the drawing the dice 1d is not shown) for clamping a rear end Nb
of a surgical needle N after a front end of a thread S has been
inserted into a hole Na formed in the end face of the rear end of
the surgical needle, so that the thread is fixed to the surgical
needle. The four pushing rods 1a to 1d are symmetrically arranged
about a longitudinal axis of the thread S so that the hole Nb of
the needle is clamped evenly from four mutually perpendicular directions.
The stroke of each pushing rods 1a to 1d can be adjusted with the
aid of micrometers 1e to 1h, respectively. The needle N is held
by a work W and the work is fed by a feeding device 2 having a guide
table. The work W is so positioned that the rear end Na of the needle
N is aligned with a center of the four pushing rods 1a to 1d. A
first guide 3 for guiding the thread S is formed as a thin tube
having a tip 3b being aligned with the rear end Na of the needle
N. The other end of the tube-like guide 3 has a tapered opening
so that the front end of a thread S can be easily inserted into
the guide. The thread S is wound on a bobbin 4 and is unwound therefrom.
The unwound thread S is passed through a sterilizing liquid contained
in a sterilizing tank 5 a sponge 6 for removing the sterilizing
liquid from the thread, a tube-like heater 7 for correcting the
curved shape of the thread into a straight shape, a pair of feeding
rollers 8 and a second guide 9. The thread S fed from the second
guide 9 is inserted into the hole formed in the first guide 3. Between
the first and second guides 3 and 9 there is arranged a cutting
device 10 such as knife and scissors.
The thread S is unwound from the bobbin 4 and is immersed into
the sterilizing liquid in the tank 5 and is sterilized thereby.
Then, the thread S is fed through the heater 7 which includes an
electric heating wire and is heated to, for instance 130.degree.
to 140.degree. C., so that the curved thread is converted into a
straight thread. It should be noted that the temperature of the
heater 7 has to be adjusted in accordance with the diameter and
material of the thread. The thread S thus processed is further fed
toward the clamping device 1 and at the same time the surgical
needle N is moved together with the work W toward the first guide
3 such that the rear end Na of the needle N is almost made in contact
with the front end 3a of the first guide 3 as illustrated in FIG.
3. That is to say, the hole Nb formed in the rear end Na of the
needle N is aligned with the front end opening of the guide 3. Then,
the thread S is further fed by means of the rollers 8 and the front
end of the thread is inserted into the hole Nb of the needle N via
the opening of the first guide 3. next, the pushing rods 1a to 1d
of the clamping device 1 are moved toward the needle to press the
rear end of the needle and the thread is firmly secured to the needle
N as shown in FIG. 4. It should be noted that the circular cross
section of the hole Nb is deformed into a substantially square cross
section by the clamping operation. The surgical needle N having
the thread S connected thereto is then fed in the leftward in FIG.
2 by a given distance by moving the feeding device 2 and after
that the thread S is cut by the cutting device 10. In the present
embodiment, the thread S is cut along an inclined line, so that
the thread has a sharp front end, and this facilitates the inserting
operation of the thread into the hole Nb of the needle as well as
the hole of the guide 3.
As explained above, with the aid of the apparatus according to
the present invention, the fine thread S can be automatically and
positively secured to the surgical needle N in a simple and efficient
manner. Particularly, in the present embodiment, since the curved
thread is first corrected into the straight thread and the front
end of the thread is easily and thus correctly inserted into the
holes of the needle N and guide 3.
FIG. 5 is a cross sectional view depicting another embodiment of
the first guide 3 according to the invention. In the present embodiment,
at a middle of the elongated guide 3 is formed a slit 3b and the
cutting blade of the cutting device 10 is inserted into the slit.
In the present embodiment, after the front end of the thread S is
once cut, the front end of the thread is not exposed out of the
guide 3 the obliquely cut front end of the thread is hardly deformed
and therefore the operation of inserting the front end of the thread
in the hole Nb of the needle N can be carried out much more positively.
FIG. 6 is a perspective view showing a positioning device for aligning
the rear end Na of the needle N with the front end 3a of the first
guide 3. The positioning device comprises two semicylindrical members
11a and 11b. The rear end Na of the needle N and the front end 3a
of the first guide 3 are clamped between the semicylindrical members
11a and 11b and then, the front end of the thread S is inserted
into the hole formed in the end face of the needle. After the centering
members 11a and 11b are removed from the needle N and the guide
3 the clamping rods 1a to 1d are moved toward the center axis.
It should be noted that the diameters of the holes formed in the
first and second guides 3 and 9 should be matched to the diameter
of the thread, and thus these guides have to be changed in accordance
with the thread to be used. For this purpose, the whole guides may
be exchanged or parts of the guides may be exchanged.
In the embodiment just explained above, the four pushing rods 1a
to 1d of the clamping device 1 are moved simultaneously, but opposite
pushing rods 1a and 1c may be first moved simultaneously and then
the remaining opposite pushing rods 1b and 1d may be simultaneously
moved. Moreover, the clamping device 1 may comprise a pair of opposite
pushing rods. In this case, after the pushing rods are moved, they
may be rotated by 90 degrees about the center axis and then are
operated again. Further, the clamping device may include more than
four pushing rods and these pushing rods may be moved simultaneously.
It should be further noted that the thread may be fed by ejecting
an air stream from an air nozzle. The thread may be cut simultaneously
with or prior to the clamping operation.
In the above mentioned embodiment, the length of the thread connected
to the surgical needle is previously determined and can not be changed
easily. In practice, it is often required to use the surgical needle
to which the threads having various lengths are connected. According
to another aspect of the present invention, the length of thread
connected to the needle can be changed easily and precisely.
FIG. 7 is a schematic view showing another embodiment of the apparatus
according to the invention. A clamping device is denoted by a reference
numeral 21 and includes two pushing rods 21a to 21b. Upon the clamping
the clamping device 21 is moved leftward from the position shown
in FIG. 7. As illustrated in FIG. 8 the pushing rods 21a and 21b
are arranged movably within a guide 21c toward the center axis from
opposite directions, so that the rear end Na of the surgical needle
N can be pressed to clamp the front end of the thread S within the
hole Nb formed in the end face of the needle. Strokes over which
the pushing rods 21a and 21b are moved can be adjusted by means
of micrometers 21d and 21e, respectively. The surgical needle N
is held by a feeding device 22 which can be moved front and rear,
up and down and can be rotated by means of motors 22a and 22b. To
the feeding device 22 surgical needles can be detachably secured
one by one with the aid of a handling apparatus not shown. It should
be noted that the needle N is held on the feeding device 22 such
that the rear end of the needle N is faced toward the clamping device
21. The thread S is wound on a bobbin 23 and is unwound therefrom.
The unwound thread S is fed along a plurality of tension adjusting
rollers 24 a brake roller 25 for applying a back tension to the
thread, a heater 26 for correcting the curved thread into the straight
thread, a pair of encoder rollers 27 to one of which is connected
a rotary encoder for measuring a length of the thread to be connected
to the needle, a feeding chuck 28 for feeding the thread while the
front end of the thread is fixed thereto, and a guide 29. The guide
29 is formed as a tube having a thin hole and is arranged movably
in the front and back directions. A front end 29a of the guide 29
is made substantially contact into the hole Nb of the needle N such
that the center axis of the front end 29a is aligned with the longitudinal
direction of the thread S. Near the front end 29a of the guide 29
is arranged a cutting device 30 for cutting the thread S. At the
clamping position there are arranged two television cameras 31a
and 31b for monitoring the connection of the thread S and the needle
N from the opposite directions. Between the feeding device 22 and
the guide 29 there are arranged five rollers 32 and 33. As shown
in FIG. 7 the two rollers 33 are arranged between the rollers 32
and are movable in the direction perpendicular to the center axis,
so that the length of the thread section situating between the guide
29 and the feeding device 22 can be adjusted over a wide range.
In case of connecting the thread S to the needle N, the thread
fixed by the chuck 28 is moved toward the feeding device 22. It
should be noted that the front end of the thread S is slightly extended
from the guide 29 which is also moved in synchronism with the chuck
28. The chuck 28 and guide 29 are moved such that the front end
of the thread S is inserted into the hole Nb formed in the end face
of the rear end Na of the needle N. Before inserting the thread
into the hole Nb of the needle, it is confirmed whether the thread
is aligned with the hole Nb or not with the aid of the television
cameras 31a and 31b.
FIG. 9 is a block diagram showing the monitoring system including
the television cameras 31a and 31b. The output video signals generated
from the television cameras are supplied to a control circuit 34
as well as to display units 35a and 35b, respectively. On the monitor
screens of the display units 35a and 35b, there are displayed images
of the front end of the thread S and the rear end of the needle
N. Since these images are taken from different directions the operator
can visually confirm the centering condition. In the control circuit
34 the front edge of the needle N is detected by processing the
scanning lines and then the center line of the needle is detected.
At the same time, the upper edge of the thread S is detected and
then the center line of the thread is detected. Then, the position
of the thus detected center lines are compared with each other to
detect a deviation between these center lines. The control circuit
34 supplies control signals to the motors 22a and 22b for adjusting
the positions of the feeding device 22 i.e. the thread S with respect
to the needle N such that the thread is accurately aligned with
the needle. In this manner, when the thread is deviated from the
hole, one or both of the feeding device 22 and the guide 29 is moved
in the direction perpendicular to the center axis until the thread
is aligned with the hole. After the front end of the thread S is
correctly inserted into the hole Nb of the needle N, the television
cameras 31a and 31b are removed from the clamping position and then
the clamping device 21 is moved into the clamping position. Next
the pushing rods 21a and 21b are simultaneously moved to press the
rear end Na of the needle N to deform the hole. Then the feeding
device 22 is rotated by 90 degrees about the center axis and the
pushing rods 22a and 22b are driven again to press the rear end
of the needle. In this manner, the thread S can be secured to the
rear end Na of the needle N as shown in FIG. 4.
After the thread has been connected to the needle as explained
above, the feeding device 22 is slightly moved in the left-hand
direction in FIG. 7 so as to check whether the thread is removed
out of the hole of the needle or not by detecting the tension applied
to the thread. Then, the chuck 28 releases the thread S and the
feeding device 22 is moved into the position illustrated in FIG.
7 to form a space between the feeding device 22 and the guide 29.
After that, the rollers 32 and 33 are moved into said space such
that the rollers 32 and 33 are positioned on opposite sides of the
thread S. Then, the rollers 33 are moved into positions between
adjacent rollers 32 to extend the thread S in the zig-zag manner.
In the manner explained above, the thread S is unwound from the
bobbin 23 by a desired length. The length of the thread unwound
from the bobbin 23 is measured by the rotary encoder coupled with
the roller 27 and when a desired length has been unwound, the brake
roller 25 is operated to apply the tension to the thread. Then,
the movement of the rollers 33 is stopped and thus the unwound operation
of the thread is completed. Next the cutting device 30 is driven
to cut the thread S. In the manner explained above, threads having
different length can be automatically connected to successive needles
N in an efficient manner.
In the above mentioned embodiment, the length of the thread S is
measured by means of the rotary encoder, but the length of the thread
may be measured by detecting the position of the rollers 33. Further,
the clamping device 21 may comprise three or four pushing rods.
Then, the clamping operation can be effected by one operation as
in the case of the first embodiment. |