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BACKGROUND OF THE INVENTION
The invention concerns a medical forceps having an elongated body with two
handle elements disposed at a first end of said body, movable with respect
to one another and two jaw parts disposed at a second end of said body
nearest the patient which jaw parts can be moved relative to one another
by means of said handles via actuating means.
A medical forceps of this kind is known from German Utility Model G 91 15
760.9. One of the two jaw parts is configured as a rigid jaw part whose
alignment is such that, together with a tube-like elongated body that
connects a handle element at the end remote from the patient with the
rigid jaw part at the end nearest the patient, it encloses an acute angle
opening toward the end remote from the patient.
The second jaw part, which is movable with respect to the first, moves
toward the tube as the jaw parts open.
A problem of the aforementioned medical forceps is that although the
dimensions of the components at the end nearest the patient are as small
as possible, the hooked configuration of the rigid jaw part is very
awkward.
One possible application for a medical forceps of this kind is to be
introduced into a human maxillary sinus in order to remove a piece of
tissue, for example a cyst, therein. The end of the medical forceps
nearest the patient can be introduced into the maxillary sinus through the
nasal opening and an opening provided in the nasal septum (called a
"window"); local anesthesia is generally sufficient in such a procedure,
so that a complex operation with general anesthesia, involving opening of
the maxillary sinus from outside, is not necessary.
Although the angled arrangement of the jaw parts makes it possible to apply
the jaw parts to the cyst being removed and to grasp it with the opened
jaw parts, the detachment process itself is nevertheless relatively
difficult to perform. Once the cyst has been grasped by the jaw parts, it
is more or less torn off by moving the entire forceps. Moreover it is
extremely difficult, because of the hooked configuration of the forceps at
the end nearest the patient, to pull it back out of the maxillary sinus,
since this entails a risk that it may catch on other tissues in an
undesirable manner.
SUMMARY OF THE INVENTION
The object of the present invention is therefore to improve a medical
forceps of the aforesaid type in such a way as to improve how the forceps
is brought into position, and the procedure for detaching tissue.
According to the invention, the object is achieved by the fact that both
jaw parts are arranged movably at the end of the forceps body nearest the
patient. In a first range of movement of the handle elements both jaw
parts can be pivoted together by means of the actuation means and that in
a second range of movement of the handle elements one jaw part can be
moved relative to the other jaw part.
These features have the substantial advantage that in the first movement
range of the handle elements, the two jaw parts can be moved together,
i.e. for example while closed against one another. This movability of the
closed jaw parts thus makes it possible to move them, at the end of the
forceps nearest the patient, to the most favorable point for bringing the
end nearest the patient into position. Taking the example of the
aforementioned process of introduction into the maxillary sinus, the jaw
parts, closed against one another, can be brought into a position in which
they can be inserted into the nose most favorably and with as little harm
to the patient as possible, i.e. in as slender a configuration as
possible. If an opening or window is present in the nasal septum, through
which the jaw parts are to be introduced into the maxillary sinus, the
closed jaw parts can be brought either into the same position in which
they were introduced into the nose or, by suitable pivoting of the jaw
parts together, into a favorable position such as to facilitate
introduction into the maxillary sinus. Once the jaw parts of the forceps
have been inserted into the maxillary sinus, for example to a location at
which a cyst must be detached, the jaw parts, still closed, then can be
brought either by rotating the entire forceps or by a further movement of
the handle elements within the first range of movement into a position in
which, for example as shown in the aforementioned German Utility Model,
the still closed jaw parts forming an angle with the elongated body of the
forceps. Because of the fact that in the second range of movement of the
handle elements, one jaw part can be moved relative to the other jaw part,
the two jaw parts can now be opened in order to grasp the tissue being
detached, for example the cyst, and applied thereto. Once the tissue has
been gripped by the jaw parts, they can be closed again by moving the
handle elements correspondingly in the opposite direction, thus holding
the tissue firmly. With a following moving of the handle elements within
the first range of movement of the handle elements again, a considerable
advantage of the invention becomes evident. The two jaw parts having
gripped the tissue can now, in the first range of movement of the handle
elements, both be moved or pivoted together, by merely moving the handle
elements with no need of moving the entire medical forceps. The jaw parts
having gripped the tissue move together away from the detachment point,
thereby advantageously supporting the process of detaching the tissue. The
combination of the features, i.e. that the jaw parts can move relative to
one another, and simultaneously that the two jaw parts can pivot together
with the tissue gripped between them, considerably facilitate the process
of gripping and detaching the piece of tissue. When the medical forceps is
subsequently withdrawn from the human body, the considerable advantage of
being able to pivot the two jaw parts together is expressed in the fact
that the said jaw parts, with the detached piece of tissue gripped
therebetween, can be moved or pivoted into a position that facilitates
withdrawal of the medical forceps from the human body.
The object is thus achieved completely.
In a further embodiment of the invention, both jaw parts are arranged
pivotedly about a common shaft or axis at the end nearest the patient.
The advantage of this feature is that the two jaw parts are arranged
pivotedly by means of a small number of components, namely the common
shaft, which produces a space-saving and slender design at the end nearest
the patient.
In a further embodiment of the invention, in the second movement range of
the handle elements one jaw part is immobilized, and the other jaw part
can move relative to the immobilized jaw part.
This feature also has the considerable advantage that the transition from
movement of the pivotable jaw parts together to movement of the jaw parts
relative to one another is made possible with simple means that are not
bulky. Only one jaw part is immobilized, for example by a stop, so that
the other jaw part can be moved further by means of the same actuation
mechanism as with the previous movement.
In a further embodiment of the invention, the actuating means comprise an
actuation element connected at one end to a handle element and at the
other end connected in an articulated fashion to that jaw part that can
also be moved in the second movement range.
The considerable advantage of this design feature is that only a single
actuation element moves the jaw part that is moved further with respect to
the immobilized jaw part, but at the same time it can also move the other
jaw part when the jaw parts move together.
In a further embodiment of the invention, the jaw part that is immobilized
in a fixed position in the second movement range can be moved, in the
first movement range, against the force of a spring away from the
immobilized position toward shared pivoting of the jaw parts, and in the
opposite direction this spring force reinforces the shared movement of the
two jaw parts together.
The considerable advantage of this feature is that, being directed from the
immobilized position toward shared pivoting, this movement of the jaw part
is performed against spring force, i.e. sufficient compression of the two
jaw parts is present during shared pivoting. During this movement, a piece
of tissue gripped by the jaw parts and detached is continuously held
firmly and thus cannot be lost. In the opposite direction, i.e. when the
jaw parts in contact with one another pivot toward the position in which
one of the jaw parts is immobilized, the spring force has a positive
reinforcing effect.
In a further embodiment of the invention, the jaw part that can be
immobilized in a fixed position is connected in an articulated fashion to
a control element, acted upon by a spring, which is movably mounted on the
handle element that is not connected to the actuation element.
The considerable advantage of this feature is that the components
generating the spring force can be arranged away from the end nearest the
patient in the region of the end remote from the patient, where
substantially more room is available, and that the spring force is
transferred by means of the control element to the jaw part at the end
nearest the patient. The arrangement of these components on the handle
element on which the actuation element is not arranged then allows
adjustment of the spring force on this other handle element entirely
independently of the actuation element, so that a spring force that is
optimal or convenient for the particular user of the medical forceps can
be set.
In a further embodiment of the invention, the control element at the end
remote from the patient is provided with an end piece on which the spring
acts.
The advantage of this feature is that the aforementioned design embodiment
of the spring force application is implemented with simple and robust
design features, making the forceps not only more convenient to use but
also more reliable.
In a further embodiment of the invention, the forceps is curved at the end
nearest the patient.
The advantage of this feature is that for certain applications, the
curvature provided immediately creates a tapered contour at the end
nearest the patient, which is suitable for introduction into body orifices
such as the nasal cavity. The additional pivotability of the jaw parts
then makes it possible to implement individually a particular optimum
orientation, or curvature and angling, of the components at the end
nearest the patient, allowing optimum adaptation not only to the intended
purpose but also to the particular anatomical conditions of the patient,
so that the forceps that be introduced and removed, adapted to his or her
anatomy, with as little harm to the patient as possible.
In a further embodiment of the invention, the forceps is an integral
component of an endoscope.
The advantage of this feature is that in combination with the endoscope,
the particular local conditions can be observed and thus the jaw parts can
be brought into the optimum orientation.
It is understood that the features mentioned above and those yet to be
explained below can be used not only in the combinations indicated, but
also in other combinations and in isolation, without leaving the context
of the present invention. The invention will be further described and
explained below with reference to an exemplary embodiment. In the drawings
,
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a side view of a medical forceps according to the invention,
in a first operating position with the jaw parts closed;
FIG. 2 shows a detailed, partial, and partly cut-away view of the medical
forceps of FIG. 1 in the region of the handle elements;
FIG. 3 shows an even further enlarged, partial, and partly cut-away
depiction of the end region nearest the patient of the medical forceps of
FIG. 1;
FIG. 4 shows a depiction, comparable to FIG. 1, of the medical forceps
according to the invention in a second operating position with the jaw
parts pivoted but still closed;
FIG. 5 shows a depiction comparable to the depiction of FIG. 2, in the
second operating position;
FIG. 6 shows a depiction comparable to FIG. 3, in the second operating
position;
FIG. 7 shows a depiction, comparable to FIG. 1, of the medical forceps
according to the invention in a third operating position with the jaw
parts open;
FIG. 8 shows a depiction comparable to FIGS. 2 and 5, in the third
operating position; and
FIG. 9 shows a depiction comparable to FIGS. 3 and 6, in the third
operating position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A medical forceps according to the invention, depicted in FIG. 1, is
labeled in its entirety with the reference number 10.
The forceps 10 has two handle elements 12 and 14 that are connected to one
another by a hinge 16. The connection is made by means of a screw 18, so
that the two handle elements 12 and 14 can pivot relative to one another
about the lengthwise center axis (not shown further here) of the screw 18.
Extending from an upper end region 20 of the handle element 12 (see also
in particular FIG. 2) are two closely adjacent tubes 22 and 24, each of
which has an outside diameter of about 1.5 mm. The tubes can be made of
steel or of a plastic material with comparable properties. The two tubes
22 and 24 provide an elongated body of the forceps 10.
At the end nearest the patient the two tubes 22, 24 end at approximately
the same level (see in particular FIG. 3), and are connected to an end
piece 26 whose outer end is configured as a fork 28. Arranged between the
two outer tines of the fork 28 are two jaw parts 30, 32 that are
accommodated pivotedly within the fork 28 by means of a shared pivot pin
34. The center lengthwise axis of the pivot pin 34 thus represents a pivot
axis for the two jaw parts 30, 32.
The jaw part 30 is connected to a control element 36 in the form of a wire
38, specifically by means of a pin 40 at the end of the wire 38, running
perpendicular to its long axis. The wire is thus configured somewhat like
the end of a Bowden cable. The pin 40 creates an articulated connection
between the end of the wire 38 and the jaw part 30. As is evident in
particular from FIG. 3, the pin 40 ends up at a distance from the pivot
pin 34.
The wire 38 is accommodated in the tube 22 and is permanently connected at
its end opposite the pin 40 to an end piece 42 (see in particular FIG. 2).
The end piece 42 is accommodated in a recess 44 in the end region 20 of
the handle element 12, the recess 44 being configured as a blind hole into
which the end piece 42 can be introduced.
Leading from a bottom surface or sidewall 56 of the recess 44 toward the
end nearest the patient is a passthrough conduit (not characterized
further here) in which the tubes 22 and 24 are arranged.
The end piece 42 has a blind hole (not characterized further here) in which
an end piece of the wire 38 is accommodated, the wire 38 being connected
in a lossproof manner to the end piece 42 by means of a clamp 54.
The end piece 42 has an annular flange section 46, facing the bottom
surface 56 of the recess 44, that continues into a cylindrical section 48
with a smaller diameter. Arranged around the cylindrical section 48 is a
helical spring 50 that braces against the upper annular surface of the
annular flange section 46. At the opposite end, the helical spring 50
braces against a snap ring 52 that is inserted in an annular groove (not
characterized further here) in the open end region of the recess 44.
The helical spring 50 is preloaded so that it has a tendency to push the
end piece 42, in the position depicted in FIG. 2, toward the bottom
surface 56 of the recess 44. Also provided in the end piece 42 is a
through hole 60 through which an actuation element 62 extends movably.
The actuation element 62 has a wire 64 whose end region remote from the
patient is permanently connected to an end sleeve 66 which projects beyond
the end of the handle element 12 that is to the right in the depiction of
FIG. 2. The end sleeve 66 is provided with external threads 68, and is
threaded into a receptacle sleeve 70 provided with internal threads 72.
The receptacle sleeve 70 is pivotedly installed in a recess 76 at the top
end of the handle element 14 by means of a screw 74.
The wire 64 extends from the end sleeve 66 through the hole 60 in the end
piece 42, and is guided through the tube 24 to the jaw part 32 (see FIG.
3). At this end nearest the patient, the wire 64 is connected in an
articulated fashion to the jaw part 32 by means of a pin 78 that runs
perpendicular to its long axis. The end region of the wire 64 is
configured identically to the end region of the wire 38, as described
above, and the pin 78 also ends up at a distance from the pivot pin 34
about which both jaw parts 30, 32 can pivot.
It is evident from FIG. 1 that a set screw 80 is provided on the handle
element 12, allowing adjustment of the first operating position (depicted
in FIG. 1) of the medical forceps 10.
It is also evident from FIG. 1 that the forceps 10 is curved at the end
nearest the patient, i.e. in the region of the end piece 26, and then
continues into the jaw parts 30, 32 which extend in a straight line in the
exemplary embodiment depicted.
The jaw parts 30, 32 are configured as straight, approximately beam-shaped
parts with cutting edges (not depicted further) resting against one
another. As will be explained below, the jaw parts are used to grasp a
piece of tissue, detach it, and hold the detached tissue between the jaw
parts.
Numerous embodiments of the jaw parts 30, 32 are possible for this purpose.
They can be configured as spoon-like nesting parts or they can be
configured as knife-like cutters with union elements, provided only that
the double function, namely detaching and holding the piece of tissue, is
possible. Furthermore it is also possible to continue the jaw parts 30,
32, in accordance with the curvature depicted in FIG. 1, in a further
curve in order, depending on the intended application, to ensure the
simplest possible introduction of the end region nearest the patient
through a body orifice, for example through a person's nasal orifice.
By opening the handle elements 12 and 14, the forceps 10 can be brought
from the first operating position depicted in FIGS. 1 to 3 to the second
operating position depicted in FIGS. 4 to 6.
During this movement the handle element 14, as depicted in FIGS. 1 and 4,
is pivoted counterclockwise about the hinge 16. As a result the wire 64 is
displaced through the tube 24 toward the end nearest the patient, thus
causing the jaw part 32 to pivot, because of the articulated connection by
means of the pin 78, about the pivot pin 34. The wire 38 follows the
movement of the wire 64, this being reinforced by the force of the helical
spring 50; in other words during this movement the end piece 42, and thus
also the wire 38 permanently connected thereto, are also displaced by the
helical spring 50 synchronously toward the end nearest the patient.
the jaw part 30 connected to the wire 38 does indeed remain closed against
the jaw part 32 and thus cannot overtake it.
This shared pivoting of jaw parts 30 and 32 while closed against one
another occurs until the end surface 58 of the end piece 42 contacts or
abuts against the bottom surface 56 of the recess 44. This situation is
depicted in FIG. 5. Further advance of the wire 38 is now blocked, i.e.
the jaw part 30 is now blocked or immobilized from further
counterclockwise pivoting.
With a further opening movement of the handle element 14, however, the wire
64 can be displaced further through the end piece 42 toward the end
nearest the patient, which causes the jaw part 32 to move further relative
to the immobilized jaw part 30 and to be pivoted about the pivot pin 34,
so that the jaw parts 30, 32 move away from one another, i.e. are opened.
Such a situation is depicted in FIGS. 7 to 9. In this third operating
position the handle elements 12 and 14 are opened almost to their maximum
extent; it is evident in particular from FIG. 8 that this is possible just
until the upper end of the handle element 14 contacts the corresponding
opposite end of the handle element 12.
In this position, with the jaw parts 30, 32 open, it is then possible to
bring between them a piece of tissue to be grasped, and to grasp said
piece of tissue by closing the handle elements 12 and 14, thereby closing
the jaw parts 30 and 32.
The closing movement of the jaw parts 30 and 32 occurs until the resistance
pressure of the piece of tissue grasped between the jaw parts 30 and 32 is
greater than the force of the spring 52. When this is exceeded, the result
of further closing of the handle elements 12 and 14 is that the end piece
42 is displaced to the right out of the position depicted in FIG. 8, i.e.
is released from immobilizing contact, thus allowing shared pivoting of
the jaw parts 30 and 32 clockwise about the pivot pin 34. The force of the
spring 50 ensures that the jaw parts 30, 32 are held closed with suitable
force, so that the piece of tissue grasped between them is held so firmly
that, because of the pivoting movement, it is detached from the location
from which it was taken. By closing the handle elements 12 and 14 further,
the jaw parts 30 and 32 can then be brought into a position that allows
the easiest possible withdrawal of the medical forceps from the removal
point.
To allow the most accurate possible observation of the detachment process
in situ, it is possible to attach the medical forceps 10 to an endoscope.
For this purpose it is possible to lay an endoscope shaft alongside the
tubes 22 and 24, and advance it to the point that its end region ends up
in the region of the end piece 26, so that the removal point and the
pivoting movement of the jaw parts 30, 32 can be precisely observed, and
then controlled, through the endoscope. It is possible to design the
forceps 10 as an integral component of an endoscope, or first to introduce
the forceps and then to guide the endoscope in along the tubes 22 and 24.
* * * * *
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