 |
Description  |
|
|
Technical Field
The present invention relates to devices for tissue sampling by so-called
coarse-needle puncture in which a driving unit is used to drive the needle
unit used for such a sampling. Specifically, the invention refers to a
novel tissue sampling device wherein the needles are consecutively
energized and wherein the driving unit provides a visual indication to the
physician of whether the device is uncocked, half-cocked, or fully cocked.
Background of the Invention
In my co-pending U.S. patent application Ser. No. 270,368, of which the
present application is a continuation-in-part, a tissue sampling device is
described for retrieving a tissue specimen from a patient. The tissue
sampling device comprises a hollow outer needle and a telescoping inner
needle having a tissue sample receiving recess near its pointed forward
end. A drive mechanism for driving the needles comprises springs for
propelling the needles and latches for sequentially releasing the needles
to be driven consecutively. In the disclosed embodiment, a tensioning
sleeve mounted to the drive mechanism is rotated to sequentially energize
the springs. When the device is actuated, the inner needle is first
propelled forward by its corresponding spring; and when the inner needle
has reached the forward extent of its travel, the hollow outer needle is
released to be propelled forward by its corresponding spring.
The apparatus disclosed in my aforesaid U.S. patent application Ser. No.
270,368 provides a number of advantages over prior art tissue sampling
devices. For example, in the device disclosed in U.S. Pat. No. 4,699,154,
which discloses a similar type of sequentially spring-propelled device for
obtaining a tissue specimen and which patent is incorporated herein by
reference, both springs are energized simultaneously by pulling a handle.
The device can require considerable effort to energize, since the
physician must overcome the force of both springs at once. However, in the
device disclosed in my co-pending U.S. patent application Ser. No.
270,368, the springs are energized sequentially, rather than
simultaneously. Thus, the device is easier to cock, since the operator
need overcome the force of only one spring at at time. Further, since it
is possible to energize the device only partially, it is possible to
retract the hollow outer needle without retracting the inner needle,
thereby to expose the tissue sample receiving notch in the inner needle
without removing the needle from the driving mechanism. Thus, this design
makes practical a single-use tissue sampling apparatus.
However, this advantageous feature of being able to energize the needles
consecutively presents a problem, in that it is not easily possible by
looking at the exterior of the device to determine visually whether the
device is uncocked, half-cocked, or fully cocked. Obviously, attempts to
retrieve a tissue specimen with an uncocked or half-cocked instrument will
be unsuccessful, and in fact the device disclosed in my aforesaid U.S.
patent application Ser. No. 270,368 will not fire if the device is not
fully cocked. But once the needle is inserted into a body cavity of a
patient and it is thereafter determined by the physician that the
instrument is uncocked or only partially cocked, the instrument cannot
easily be further energized with the tip of the needle still within the
body cavity of the patient without risk of injury to the patient. Rather,
the instrument must be withdrawn, the tensioning sequence completed, and
the needle tip then reintroduced into the body cavity. Such withdrawal and
reintroduction increases the duration and discomfort of the procedure and
increases the risk to the patient of injury or infection.
Thus, it would be desirable to provide a tissue sampling device of the type
described which provides a visual indication to the physician indicating
whether the instrument is fully energized, partially energized, or
altogether uncocked.
Summary of the Invention
Stated generally, the present invention relates to a tissue sample
retrieval device comprising a pair of telescoping spring-driven needles
which are sequentially actuated, wherein the device is characterized by a
means for providing a visual indication to the physician as to whether or
not the instrument is fully energized.
Stated somewhat more specifically, the tissue sampling device of the
present invention comprises a guide sleeve having front and rear guide
sleeve ends and defining a longitudinal axis extending between the front
and rear guide sleeve ends. A hollow first needle is positioned within the
guide sleeve and extends from the front guide sleeve end. A second needle
extends through the hollow first needle and has a tip which is extendable
from the hollow first needle and a tissue sample receiving recess located
adjacent the tip.
A first needle holder is coupled to the hollow first needle and is mounted
within the guide sleeve for movement along the longitudinal axis of the
guide sleeve so as to move the hollow first needle along the axis.
Similarly, a second needle holder is coupled to the second needle and is
also mounted within the guide sleeve for movement along the longitudinal
axis of the guide sleeve to move the second needle along the axis. A first
spring disposed within the guide sleeve and operatively associated with
the second needle holder is capable of being placed into an energized mode
to store energy. A first latch selectively releasable from outside the
guide sleeve retains the first spring in the energized mode. Similarly, a
second spring positioned within the guide sleeve and operatively
associated with the first needle holder is capable of being placed into an
energized mode to store energy. A second latch retains the second spring
in the energized mode, and the second latch is releasable in response to
and subsequent to release of the first spring.
A tensioning sleeve is rotatably mounted on the guide sleeve and is
operative upon rotation thereof to move the first needle holder and the
second needle holder along the axis towards the rear guide sleeve end to
cause the first latch means to hold the first spring in the energized mode
and to cause the second latch means to hold the second spring in the
energized mode. An indicator means, operatively associated with one of the
first and second needle holders and visible from without the tensioning
sleeve, indicates the energized status of the first and second springs,
whereby a user can visually confirm by viewing the indicator means whether
the springs are in the energized modes.
When the first latch is released, the first spring propels the second
needle holder along the axis towards the front guide sleeve end, such that
the tip of the second needle is extended from the hollow first needle,
whereby a tissue sample can be captured within the recess. In response to
and subsequent to the release of the first spring, the second latch
releases the second spring to propel the first needle holder along the
axis towards the front guide sleeve end, the hollow first needle thereby
being extended from the front guide sleeve end such that the recess of the
second needle is enclosed by the hollow first needle.
Thus, it is an object of the present invention to provide an improved
tissue sampling device for retrieving specimens of internal body tissue of
a patient for biopsy.
It is another object of the present invention to provide a tissue sampling
device of the type described which provides a visual indication to the
physician indicating whether the instrument is fully energized, partially
energized, or altogether de-energized.
Other objects, features, and advantages of the present invention will
become apparent upon reading the following specification, when taken in
conjunction with the drawings and the appended claims.
Brief Description of the Drawings
FIG. 1 is a side view of a sleeve forming the outer wall of the driving
unit of a first embodiment of a tissue sampling device according to the
present invention.
FIG. 2 is an end view of the sleeve shown in FIG. 1 seen in the direction
of the arrows II--II.
FIG. 3 is a central longitudinal section of the sleeve shown in FIGS. 1 and
2.
FIG. 4 is a flattened view of the sleeve shown in FIGS. 1-3.
FIG. 5 is a side view of the needle holder of the solid needle of the first
embodiment, it being understood that the needle holder for the tubular
needle has a substantially corresponding shape.
FIG. 6 is an end view of the end opposite to the needle of the needle
holder shown in FIG. 5.
FIG. 7 is a side view of one half of the guide sleeve composed of two
halves.
FIG. 8 is a plan view from the concave side of the sleeve half shown in
FIG. 7.
FIG. 9 is a section of the driving unit according to the invention in the
released condition.
FIG. 10 is a section corresponding to FIG. 9 but showing the portions in
their pre-tensioned condition.
FIG. 11 is a side view of a tensioning sleeve of an alternate embodiment of
a tissue sample retrieving device according to the present invention.
FIG. 12 is a section of the driving unit of the alternate embodiment in a
released condition.
FIG. 13 is a section of the driving unit of FIG. 12 showing the driving
unit in a partially energized configuration.
FIG. 14 is a section of the driving unit of FIG. 12 showing the driving
unit in a fully energized configuration.
Detailed Description of the Disclosed Embodiment
Referring now to the drawings, in which like numerals indicate like
elements throughout the several views, a first embodiment of a tissue
sampling device for biopsy purposes is disclosed in FIGS. 1-10 and
comprises a needle unit and a driving unit in combination. As mentioned
initially, the needle unit and the sampling procedure are previously known
and will therefore not be described in any great detail.
The driving unit 1 of the first embodiment comprises an outer tensioning
sleeve 2 (FIGS. 1-4), an internal guide sleeve 3 (FIGS. 7 and 8), two
needle holders 4a, 4b, two driving springs 5a, 5b, and a triggering knob 6
(FIGS. 9 and 10). Attached within the first or forward needle holder 4a is
a tubular needle 7a whereas attached to the second or rear needle holder
4b is a solid needle 7b having a recess 8 (FIG. 5) for receiving a tissue
sample, said latter solid needle 7b extending slidably through the tubular
needle 7a.
The outer sleeve or tensioning sleeve 2 forms the outer wall of the driving
unit. At its narrow end the sleeve 2 carries a set of tongues 10, the free
outer ends of which are radially pre-tensioned in an inward direction. The
function of these tongues will become apparent as the assembly is
explained hereinbelow. As seen in FIG. 2, the sleeve 2 is of substantially
circular cross-section but has step-wise diminishing diameter. The steps
between the various diameters form cam surfaces, a rear cam surface 11 and
a forward cam surface 12, extending radially into the sleeve. In the
embodiment shown these cam surfaces 11, 12 are double, which means that
the cam surfaces 11, 12 are symmetrically repeated twice on the
circumference. The shape and function of the cam surfaces 11, 12 will be
described hereinbelow.
The inner sleeve or guide sleeve 3 comprises two identical halves 13 which
may be put together in a conventional way with the aid of pins and holes
to form a unit of substantially cylindrical shape and circular cross
section. The guide sleeve 3 has a handle 14 formed at its rear end. At the
forward end of the guide sleeve 3, an axially directed hole 15 is formed
through which the needles 7a, 7b are to extend and which also serves as a
guide for the needles. Also at the forward end a radially inwardly
extending circular groove 16 is adapted to receive the tongues 10 of the
tensioning sleeve 2. A circular depression 17 is provided on the handle 14
facing in an inward direction and adapted to be inserted into the
tensioning sleeve 2 when the unit is assembled. The guide sleeve 3 also
has two circular flanges 18, 19 adapted to abut against the inner surface
of the tensioning sleeve 2. Two pairs of axially extending guide grooves
20, 21 in diametrically opposed positions extend through the wall of the
guide sleeve 3.
Within the guide sleeve 3 a circular shoulder 22 is formed at the needle
end and comprises an abutment for the forward needle holder 4a. Similarly,
an intermediate circular shoulder 23 forms an abutment for the rear needle
holder 4b and provides a seat for the driving spring 5a for the forward
needle holder 4a. A rear circular shoulder 24 forms a seat for the driving
spring 5b for the rear needle holder 4b. Both the rear shoulder 24 and the
intermediate shoulder 23 also form parts of the locking mechanism during
loading or tensioning of the driving unit of the sampling device, in
particular if the driving springs 5a and 5b are compressed.
Within the handle 14 there are in addition provided two opposite axially
extending grooves 25 cooperating with grooves or recesses 26 in the
tensioning sleeve 2 to prevent the sampling device from being triggered
except in one definite position, as well as guides for the triggering knob
6.
As appears from FIGS. 5 and 6, each of the needle holders 4a, 4b comprises
a body 30 having a width slightly narrower than the inner diameter of the
guide sleeve 3. On the one side of the plate 30 a pair of radially
extending wings 31 are provided extending slightly beyond the periphery of
the plate 30. On the opposite side of the plate 30 a pair of axially
extending arms 32 project rearward, said arms being resilient and provided
at their outer free ends with outwardly extending hooks 33. These hooks 33
are adapted in the driving unit's tensioned condition to rest behind a
shoulder 23 and 24 respectively, a pressure spring 5a, 5b being inserted
about the arms 32 between the plate 30 and the respective shoulder 23, 24.
Each of the wings 31 has a downward and inwardly sloping surface 34. For
releasing the sampling device, these surfaces 34 cooperate with the hooks
33 of the arms 32, the hooks 33 sliding along the surfaces 34 and being
shifted towards each other to release them from their engagement with the
respective shoulder 23, 24.
The wings 31 are guided in slots 20, 21 thus preventing rotation of the
needle holders 4a, 4b in relation to the guide sleeve 3. The wings 31
extend through the axially extending guide slots 20, 21 in the guide
sleeve 3 and towards the inner surface of the tensioning sleeve 2 to
engage the cam surfaces 11, 12 formed thereon.
The assemblage of the driving unit 1 is performed substantially in the
manner now to be described. The two needle holders 4a, 4b together with
their needles 7a, 7b and with the springs 5a, 5b positioned about their
arms 32 are placed in position in the one half of the guide sleeve 3. The
trigger knob 6 is also inserted in the one half of the guide sleeve,
whereafter the other half of the guide sleeve 3 is assembled onto the
first half with the pins in one guide sleeve half engaging corresponding
holes in the other guide sleeve half. Thereafter, the tensioning sleeve 2
is passed axially over the guide sleeve 3, causing the tongues 10 to
engage the groove 16, while the opposite end of the tensioning sleeve 2
encloses the guide sleeve 3 at the depression 17. In this position the
unit is ready for use. It will be appreciated that the parts used are of
simple and cheap construction, to the extent possible consisting of
plastics or similar materials, only springs 5a, 5b and the needles 7a, 7b
proper consisting of metal and in addition being light-weight.
The driving unit of the sampling device operates in the manner now to be
described. The sampling device, which in itself is of the single-use type,
may be loaded several times without problems and is manufactured with
different needle thicknesses and needle lengths depending on the intended
use. The physician thus chooses a sampling device adapted for the sampling
in question. This device, however, is not initially tensioned in order to
avoid deformation of certain parts due to the spring forces, but
tensioning is to be performed immediately prior to sampling. For this
purpose the handle 14 is held with the one hand while the other hand
seizes the tensioning sleeve 2 to perform relative rotation of these
parts. As the handle is rotated relative to the sleeve, the wings 31a of
the forward needle holder 4a are shifted along the steep portion of the
cam surface 12, thereby compressing the forward spring 5a. The wings 31b
of the rear needle holder 4b follow at the same time the flattened portion
36 of the cam surface 11 to arrive at the end behind catch 37. In this
position backward rotation to the starting position is no longer possible,
but the rear needle holder 4b is raised to such an extent that it cannot
come into contact with the hooks 33a of the forward needle holder 4a when
these enter into the locking position behind the intermediate shoulder 23.
During continued rotation the forward wings 31a follow the plane cam
surface 38a whereas the rear wings 31b follow the steep cam surface 39
causing the rear spring 5b to be compressed. If the physician should lose
his grip during this part of the tensioning procedure, the rear needle
holder 4b moves towards the starting position but is retained in front of
catch 37 and thus cannot release the forward needle holder 4a.
When the wings 31b have been advanced along cam surface 39 during continued
rotation, they are lifted over a catch 40. Thereafter reverse rotation is
impossible and continued rotation is prevented by an abutment 41. In this
position the recesses 26 are situated exactly opposite grooves 25 in the
guide sleeve 3 and the triggering knob 6 may be depressed. The sampling
device is now tensioned and ready for sampling.
The triggering knob 6 is connected to a cross element 42 having a
substantially V-shaped depression 43 in its central portion. When the
triggering knob 6 is depressed, which is possible due to the fact that
grooves 25 and 26 are mutually aligned, the flanges of the V-shaped
portion 43 will bias the hooks 33b towards each other, causing them to
lose contact with the shoulder 24 and enabling the spring 5b to propel the
inner needle 7b forward. When the rear needle holder 4b approaches the
shoulder 23 at the forward extent of its travel, the sloping surfaces 34
on the forward portion of the rear needle holder 4b engage the hooks 33a
on the forward needle holder 4a, biasing the hooks inwardly and
disengaging them from the shoulder 23. The forward needle holder 4a is
thereby released from its engagement with the intermediate shoulder 23 to
be propelled forward by its corresponding spring 5a. Consequently, the
solid inner needle 7b, with its tissue-receiving cavity 8 formed adjacent
its tip, is propelled first, whereafter the tubular outer needle 7a is
released to resect the tissue received in said cavity. If additional
samples are to be taken, the tubular needle 7a is retracted to provide
access to the recess 8 and the tissue sample captured therewithin, which
is accomplished by rotating the sleeve 2 in relation to the handle 14 to
the first locking position in which the wings 31b are retained behind the
catch 37.
The sequential tensioning sequence hereinabove described, wherein rotation
of the tensioning sleeve energizes first one spring and then the other,
provides the advantage that, since only one spring at a time is being
energized, the physician need exert only enough force on the tensioning
sleeve to overcome the force of one spring, rather than having to overcome
the force of both springs simultaneously. However, this sequential cocking
arrangement presents the possibility that the physician might unknowingly
energize only the first spring and go no further, not realizing that the
driving device is not fully energized. To overcome this problem, an
alternate embodiment of a tissue sampling device 100 according to the
present invention, disclosed in FIGS. 11-14, comprises a means for
providing a visual indication to the physician that the device is fully
energized, only partially energized, or completely uncocked.
The alternate embodiment of the tissue sampling device 100 includes a
driving unit 101 which is in many respects identical to the driving unit 1
of the previously described embodiment. Therefore, for purposes of the
description of the alternate embodiment of the tissue sampling device 100,
only those elements which differ from their corresponding elements of the
driving unit 1 will now be described, it being understood that the
remaining elements are identical to the corresponding elements of the
driving unit 1.
The driving unit 101 of the alternate embodiment 100 includes a tensioning
sleeve 102 which differs from the tensioning sleeve 2 previously described
only in that the tensioning sleeve 102 includes a pair of windows formed
therethrough. The exact location and purpose of these windows 150, 152
will be more fully described below.
The driving unit 101 comprises a pair of needle holders 4a and 104b. The
first or forward needle holder 4a has the tubular needle or cannula 7a
attached thereto, and the second or rear needle holder 104b has the solid
needle or stylet 7b attached thereto. The rear needle holder 104b differs
from the rear needle holder 4b of the previously disclosed embodiment in
that the rear needle holder 104b includes an indicator element 154
extending rearward from one of the radially extending wings 31. In the
disclosed embodiment, the indicator element 154 is molded from a plastic
having a contrasting color to the sleeve 102 for ready visibility and has
an arrow inscribed thereon. When the rear needle holder 104b is installed
in the guide sleeve 3 in the manner depicted in FIGS. 12-14, the indicator
element 154 is disposed in the annular space between the guide sleeve 3
and the tensioning sleeve 102 and extends rearward in a direction
substantially parallel to the inner wall of the tensioning sleeve.
The locations of the windows 150, 152 in the tensioning sleeve 102 are
determined with respect to the forwardmost and rearwardmost positions of
the indicator element 154 on the rear needle holder 104b, as will be
explained with reference to FIGS. 12-14. The forward window 150 is
disposed such that when the driving unit 101 is in its released or
untensioned condition with the rear needle holder 104b in its forwardmost
position, as illustrated in FIG. 12, the indicator element 154 on the rear
needle holder is aligned with the window 150 so as to be visible
therethrough. Similarly, the rear window 152 is located such that when the
driving unit 101 is in its fully tensioned state with the rear needle
holder 104b in its rearmost position, as depicted in FIG. 14, the
indicator element 154 on the rear needle holder corresponds with the
location of the rear window 152 so as to be visible therethrough.
Assembly of the driving unit 101 of the alternate embodiment 100 is
essentially the same as the assembly of the driving unit 1 of the
previously disclosed embodiment. The rear needle holder 104b is assembled
onto the guide sleeve 3 with the radial wings 31 of the rear needle holder
riding in the longitudinal slots 21 of the guide sleeve and the indicator
element 154 disposed outwardly of the guide sleeve. Also, when assembling
the tensioning sleeve 102 onto the guide sleeve 3, care must be taken to
align the tensioning sleeve rotationally so that the indicator element 154
is visible through the front window 150 when the driving unit is in its
untensioned configuration.
Operation of the alternate embodiment of the tissue sampling device 100
will now be described. The driving unit 101 of the tissue sampling device
100 is energized in the same manner as hereinabove described with respect
to the driving unit 1 of the previously described embodiment. In the
untensioned condition, as shown in FIG. 12, the forward needle holder 4a
and the rear needle holder 104b are both in their forwardmost positions,
and the indicator element 154 is visible through the front window 150,
indicating to the physician that the unit is uncocked. To initiate the
energizing sequence, the physician holds the tensioning sleeve stationary
in one hand while rotating the handle 14 of the device with the other. As
the handle 14 is rotated through the first 180.degree. of movement, the
forward cam surface on the inner wall of the tensioning sleeve 102 biases
the front needle holder 4a rearward in the same manner hereinabove
described with respect to the drive unit 1 of the previously disclosed
embodiment. In this partially cocked configuration, illustrated in FIG.
13, the front needle head 4a is in its rearmost position, while the rear
needle holder 104b is still in its forwardmost position. Also in this
configuration, the rear needle holder 104b has been rotated 180.degree.
from its beginning position such that the indicator element 154 is on the
side of the driving unit opposite the window 150 in the tensioning sleeve.
Thus, even though the rear needle holder 104b has not moved axially from
its initial position, the indicator element 154 is nonetheless not visible
through either of the windows 150, 152.
As the energizing sequence is continued, the handle 14 is rotated an
additional 180.degree. with respect to the tensioning sleeve 102 until the
drive unit 101 attains the fully energized state illustrated in FIG. 14.
In this fully tensioned state, both needle holders 4a, 104b are in their
rearmost positions. The rear needle holder has now been rotated a full
360.degree. from its initial position such that the indicator element 154
is once again on the same side of the drive unit as the windows 150, 152.
However, the rear needle holder 104b has now been biased to its rearmost
position such that the indicator element is visible through the rear
window 152, rather than the front window 150.
The physician may thus visually confirm the cocking status of the driving
unit 101 by observing the windows 150, 152 in the tensioning sleeve 102.
If the indicator element 154 on the second needle holder 104b can be seen
through the front window 150 in the tensioning sleeve 102, the physician
knows that the driving unit 101 is fully uncocked. If the indicator
element 154 is not visible through either of the two windows 150, 152,
then the physician will know that the driving unit 101 is partially
cocked, that is, the front needle holder 4a is cocked but the rear needle
holder 104b is still uncocked. If the indicator element 154 is visible
through the rear window 42 in the tensioning sleeve 2, then the physician
knows that the driving unit 1 is fully energized and ready for use. This
feature of windows in the tensioning sleeve through which an indicator
element can be viewed to provide a visual indication to the physician
whether the instrument is fully energized, partially energized, or
altogether uncocked is particularly advantageous in the sequentially
energized embodiment, so that the physician will not attempt to use an
uncocked or only partially cocked device.
While the alternate embodiment 100 of the tissue sampling device has been
disclosed with respect to a tensioning sleeve 102 having windows 150, 152
located to correspond to an indicator element 154 on the rear needle
holder, it will be appreciated that similar results can be obtained by
locating the indicator element on the front needle holder and moving the
windows forward correspondingly. In such an arrangement, a front window
would be disposed to reveal the indicator element when the driving unit is
in its fully uncocked or released condition, while the rear window would
be located so as to reveal the indicator element when the driving unit is
in its fully tensioned or fully energized state. When the driving unit has
been only partially energized, the front needle holder will have been
moved to its rearmost position but will also have been rotated 180.degree.
so as not to be visible through either of the windows. When the driving
unit has been fully cocked, the front needle holder will have been rotated
a full 360.degree. and will now be visible through the rear window.
In addition, while the driving unit 101 has been disclosed with respect to
an embodiment having a pair of windows 150, 152, it will be appreciated
that satisfactory, though somewhat less informative, results may be
achieved by a tensioning sleeve having only a single window aligned to
reveal an indicator element only when the driving unit has been completely
cocked. While such an arrangement would indicate only whether or not the
device is fully energized and would not differentiate between a driving
unit which is completely released and a driving unit which is partially
energized, this arrangement would nonetheless indicate to the physician
that further energizing is necessary before the unit is ready for use and
hence would provide a significant advantage over the drive unit 1 of the
previously disclosed embodiment which does not have any means whatsoever
of providing a visual confirmation that the device is cocked.
Finally, it will be understood that the foregoing embodiments have been
disclosed by way of example, and that other modifications may occur to
those skilled in the art without departing from the scope and spirit of
the appended claims.
* * * * *
|
|
 |
|
 |
Description |
|
