U.S. patent number 3,736,932 [Application Number 05/226,615] was granted by the patent office on 1973-06-05 for injection apparatus with filter.
This patent grant is currently assigned to Sherwood Medical Industries Inc.. Invention is credited to Fred E. Satchell.
United States Patent |
3,736,932 |
Satchell |
June 5, 1973 |
INJECTION APPARATUS WITH FILTER
Abstract
A fluid medicament injection device is provided which has a
housing, a chamber in the housing, a metallic filter dividing the
chamber into forward and rearward portions, and a needle mounted
for movement relative to the filter. In one position of the needle,
it is in direct fluid communication with the forward portion of the
chamber so that fluid flowing between the forward and rearward
chamber portions is filtered by the filter, and in another
position, the needle by-passes the forward chamber portion and the
filter, and is in direct fluid communication with the rearward
chamber portion.
Inventors: |
Satchell; Fred E.
(Chesterfield, MO) |
Assignee: |
Sherwood Medical Industries
Inc. (St. Louis, MO)
|
Family
ID: |
22849654 |
Appl.
No.: |
05/226,615 |
Filed: |
February 15, 1972 |
Current U.S.
Class: |
604/190 |
Current CPC
Class: |
A61M
5/348 (20130101); A61M 5/178 (20130101); A61M
5/3145 (20130101); A61M 5/288 (20130101) |
Current International
Class: |
A61M
5/178 (20060101); A61M 5/31 (20060101); A61M
5/34 (20060101); A61b 010/00 (); A61m 005/00 () |
Field of
Search: |
;128/218R,215,218D,224,230,234,235 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Medbery; Aldrich F.
Claims
I claim:
1. In fluid medicament injection apparatus, the combination
comprising housing means having a chamber therein, filter means in
said chamber for filtering fluid medicament flowing therethrough,
said filter means dividing said chamber into a pair of chamber
portions, and cannula means having spaced openings therein, said
filter and cannula means being relatively movable to effect the
positioning of one of said openings from within one of said chamber
portions to a location within the other of said chamber
portions.
2. The apparatus according to claim 1 wherein said filter means has
an aperture therein for receiving said cannula means.
3. The apparatus according to claim 2 wherein said filter means
includes puncturable seal means normally closing said aperture and
which is punctured by said cannula in response to relative movement
between said filter and cannula means.
4. The apparatus according to claim 2 wherein said cannula means is
closed at one end and is sized to move in said aperture and
substantially close said aperture.
5. The apparatus according to claim 4 wherein said one opening is
disposed in the side wall of said cannula means.
6. The apparatus according to claim 2 wherein said housing means
comprises a syringe barrel.
7. The apparatus according to claim 2 wherein said housing means
comprises a member having one end with an opening adapted to
receive one end of a syringe barrel, and an opposite end having an
opening adapted to receive said cannula means.
8. The apparatus according to claim 1 wherein said filter means
comprises a filter element of metal.
9. In fluid medicament injection apparatus, the combination
comprising housing means having a fluid chamber therein, filter
means having an aperture therein and disposed in said chamber for
filtering fluid flowing therethrough, said filter means dividing
said chamber into distal and proximal chamber portions, cannula
means, and coupling means connected to said cannula means and
coupled to said housing means for movement relative thereto for
selectively positioning said cannula means in a first position with
said cannula means in direct fluid communication with said distal
chamber and a second position with said cannula means in direct
fluid communication with said proximal chamber portion and in fluid
by-passing relation with said filter means and said distal chamber
portion, said cannula means being movable in said aperture.
10. The apparatus according to claim 9 further including piston
means slidable in said housing means for effecting fluid pressure
in said chamber.
11. The apparatus according to claim 10 wherein said cannula
comprises a hypodermic needle having distal and proximal openings
respectively disposed in distal and proximal end portions thereof,
said proximal end portion moves in said aperture during movement of
said cannula from one of said first and second positions to the
other of said first and second positions.
12. The apparatus according to claim 11 wherein said filter means
includes seal means normally closing said aperture, and said
proximal end portion has a pointed end for puncturing said seal
means when said proximal end portion moves in said aperture.
13. The apparatus according to claim 11 wherein the proximal end of
said proximal end portion is closed, said proximal opening is in
the side wall of said proximal end portion, and said needle is
sized to maintain said aperture substantially closed when said
needle is in said first position and also when it is in said second
position.
14. The apparatus according to claim 11 wherein said coupling means
comprises a hub, said housing means comprises a main barrel
portion, and a distal extension portion having a smaller outer
diameter than that of said barrel portion for receiving said hub,
and a generally radially inwardly extending portion connected
between said extension portion and said barrel portion, said hub
and said extension portion having cooperating abuttment means
thereon for selectively locating said hub relative to said housing
means to position said cannula selectively in said first and second
positions.
15. The apparatus according to claim 14 wherein said filter is
disposed in said housing means in engagement with the juncture
between said barrel and said extension portions.
16. A hypodermic syringe comprising a hub, a hypodermic needle
fixed to said hub and having distal and proximal openings therein,
a barrel having a bore, and a distal end portion receiving said hub
to connect said needle in fluid communication with said bore, a
filter disposed in said bore adjacent to said distal end portion
and dividing said bore into distal and proximal chambers, said
filter having a normally closed aperture therein aligned in
relation with said needle, said hub and said needle being movable
relative to said barrel to selectively position said proximal
opening in said barrel on the distal side of said filter with said
needle in series fluid communication with said distal and proximal
chambers and said filter, and to position said proximal opening in
said barrel on the proximal side of said filter with said needle
extending in said aperture in direct fluid communication with said
proximal chamber and in fluid by-passing relation with said filter
and said distal chamber, and plunger means including piston means
slidable in said bore for moving fluid through said needle.
17. The hypodermic syringe according to claim 16 further including
seal means normally closing said aperture, and wherein said needle
pierces said seal means when moving from one of said sides of said
filter to the other of said sides.
18. The hypodermic syringe according to claim 16 wherein said
aperture is closed by said needle when said proximal opening is on
said distal side of said filter and when it is on said proximal
side of said filter.
19. The hypodermic syringe according to claim 16 wherein said
filter comprises an annular disc-like member formed of metallic
fibers.
20. A filter unit for use in filtering fluid medicament in
medicament injection apparatus comprising a housing having a
chamber, a filter having two faces and means for receiving a needle
end, said filter being disposed in said chamber dividing said
chamber into distal and proximal chamber portions respectively
adjacent said faces, said housing having a proximal end portion for
coupling a hypodermic syringe barrel thereto in fluid communication
with the chamber, said housing having a distal end portion for
sealingly receiving the hub of a needle and hub assembly for
connecting the proximal opening end of the needle of said assembly
selectively in said distal chamber and said proximal chamber.
Description
BACKGROUND OF THE INVENTION
This invention relates to medicament injection devices, and more
particularly to a medicament injection syringe apparatus.
Conventionally, the distal end of a hypodermic needle of an
injection device, such as a hypodermic syringe, is inserted through
an enclosure member of an ampule containing medicament to draw
medicament into the barrel portion of the syringe. Such enclosure
members are often relatively thick rubber plug members. One serious
problem in the use of conventional hypodermic syringes is that the
needle as it passes through the rubber plug sometimes causes a
coring thereof and there is the danger of particles of such coring
entering into the medicament as it is drawn into the syringe. In
addition to such particles, there is the danger that other debris
or contaminations, such as crystallized medicament, may be passed
into the syringe. Thus, the danger of injecting foreign particles
or contaminations into the patient when using conventional
hypodermic syringes under certain circumstances has been
present.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a
medicament injection device which substantially obviates the above
mentioned disadvantages.
A specific object of the present invention is to provide a
hypodermic injection device which substantially obviates the
possibility of injecting contaminants into a patient.
Another object is to provide a novel hypodermic syringe having
filter means for preventing the injection of undesirable particles
into the patient.
Still another object is to provide a novel filter unit readily
connectable between a syringe and a needle for filtering
medicament.
In accordance with one form of the present invention, medicament
syringe apparatus is provided which includes a housing having a
chamber, a filter member in the chamber, and a cannula, the cannula
and filter being relatively movable whereby the cannula, when in
one position, has an opening in the chamber at one side of the
filter member, and in another position, the opening in the cannula
is on the other side of the filter member.
These, as well as other features and advantages of the present
invention will become apparent from the following detailed
description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal sectional view of a hypodermic syringe in
accordance with one embodiment of present invention;
FIG. 2 is a sectional view of the hypodermic syringe of FIG. 1
showing the hypodermic needle in by-passing relation with the
filter;
FIG. 3 is an enlarged cross-sectional view taken along line 3--3 of
FIG. 1;
FIG. 4 is a longitudinal sectional view, with parts broken away, of
a hypodermic syringe illustrating a modified embodiment according
to the present invention;
FIG. 5 is a sectional view of the hypodermic syringe of FIG. 4, but
with the needle in by-passing relation with the filter;
FIG. 6 is an enlarged cross-sectional view of the proximal end
portion of the needle of FIG. 4; and
FIG. 7 illustrates medicament syringe apparatus in accordance with
still another embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawing, and particularly to FIGS. 1, 2 and 3,
there is shown a medicament injection apparatus in the form of a
hypodermic syringe 10 in accordance with a preferred embodiment of
the invention. The hypodermic syringe 10 is shown including a
syringe 12 having a transparent housing or barrel 14 and a plunger
assembly 16 reciprocal in the barrel 14, a selectively movable
needle and hub assembly 18, and a filter member 20 disposed in the
barrel 14.
The plunger 16 includes a plunger rod 21 and a piston 22 connected
to the forward or right-hand end thereof and which is in sealing,
sliding engagement with the bore or chamber 23 of the barrel 14.
The rod 21 is provided at the rearward or left-hand end with an
enlarged plunger end 21a adapted to be engaged by the thumb. The
piston 22 is preferably formed of rubber or the like. The barrel 14
is provided with a connector end portion 25 shown as an integral,
longitudinally extending, distal end portion which is adapted to
receive a hub 27 of the hub and needle assembly 18. A cannula,
shown as a hypodermic needle 28, is fixed to the hub 27 in any
suitable or conventional manner, and it extends through the hub and
into an axially extending opening 29 in the forward end portion 25
of the barrel. Hub 27 is provided with an annular bead or rib 30
formed on the internal surface thereof which, in FIG. 1, is
disposed between a pair of spaced external annular ribs 31 and 32
on the end portion 25 to predeterminately position the needle hub
assembly 18 with respect to the barrel 14 and filter 20. The hub 27
is, of course, connected in sealing or fluid-tight engagement with
the barrel. Another annular rib 33 is provided on end portion 25
for locating the assembly 18 in its second position, as will be
explained hereinafter. Needle 28 is shown pointed at the opposite
end portions 34 and 35, the ends being shown beveled. The needle 28
has a lumen extending between the opposite ends thereof with an
inner opening 34a at the rearward or proximal end portion 34, and
an outer opening 35a at the forward or distal end portion 35.
The filter member 20 is shown disposed in the barrel chamber 23 and
divides the chamber 23 into rearward or proximal, and forward or
distal, chamber portions, indicated respectfully at 23a and 23b.
The filter member 20 includes a disc or annular plate element 40
formed of a filtering material and having a central aperture or
opening 42 in aligned relation with needle 28 and which receives a
seal or relatively thin plug member 44. Seal member 44 is formed of
a suitable material such as rubber which will not break away or
core when pierced by the needle 28. Seal member 44 is shown having
a peripheral groove 46 which receives the inner wall of opening 42
in tight frictional engagement to secure the seal in the opening
42.
The material forming filter element 40, while it may be formed of
any suitable material that will provide adequate filtering, is
preferably formed of a metallic material, for example, a material
formed of metal fibers bonded together, for example, by a sintering
process, and then cut to the desired configuration. Depending upon
the desired filtering characteristics, such materials as wire mesh,
sintered powder, collimated metal type sheet, or the like, or
non-metallic materials, can be used.
Filter member 20 is secured in the forward end of the bore 23 with
the outer periphery thereof in fluid tight engagement with the bore
walls. In the illustrated embodiment, the outer periphery of the
filter member 20 is circular and of a predetermined dimension
relative to the bore 23 such that, when inserted from the open end
of barrel 14 during assembly of the syringe, it is slidable into
the bore 23 and has a tight friction fit therewith. The filter
member bottoms against the radially inwardly inclined or conical
forward portion of the barrel, indicated at 47, and which connects
the main cylindrical barrel portion with the end portion 25. In
this way, the filter member 20 remains in place adjacent the
forward or right end of bore 23.
In operation, with the hub and needle assembly 18 positioned as
shown in FIG. 1 and with the plunger assembly 16 in a forward
position in the barrel, the distal end portion 35 of needle 28 is
inserted, for example, into a vial of liquid medicament, and the
piston 22 is retracted or moved rearwardly in bore 23 toward the
left end thereof. Medicament is drawn up through the needle lumen
into forward chamber portion 23b, through the filter element 40,
and into the rearward chamber portion 23a, in response to the
negative pressure in the barrel produced by the rearward movement
of the plunger piston 22. In this way, the medicament is filtered
by filter member 20 to provide a filtered medicament in the chamber
portion 23a, which chamber portion serves as a reservoir chamber.
Any foreign particles or other contamination will remain in the
chamber portion 23b or be trapped by the filter member. Thus in
FIG. 1, the proximal end 34 of needle 28 is in the chamber portion
23b on the distal side of filter member 20, the needle lumen being
in direct or unobstructed communication with the chamber portion
23b and opening 29 which is part of chamber portion 23b in the
illustrated embodiment, so that the needle lumen is in series fluid
communication with the chamber 23b, the filter member 20, and the
reservoir chamber portion 23a.
When it is desired to discharge the filtered medicament from the
reservoir chamber 23a, for example, to inject such medicament into
a patient, the hub and needle assembly 18 is first grasped and
moved rearwardly relative to the syringe 12 to position the
assembly 18 as indicated in FIG. 2. It is seen that the annular rib
30 of the hub 27 is moved over annular rib 32 and 33 on the barrel
extension 25. Thus, in FIG. 2, the needle and hub assembly is
positioned with the needle piercing the seal member 44 of the
filter member 20 and in fluid-flow by-passing relation with the
filter member so that the proximal end opening 34a of the needle
lumen is disposed in the reservoir chamber portion 23a in direct
fluid communication with the filtered medicament. When the outer
distal end opening 35a of needle 28 is inserted, for example, in a
patient, and a force applied to the rearward end of the plunger
assembly 16, piston 22 moves forwardly in the barrel bore 23
forcing the filtered fluid medicament from the chamber portion 23a
into the opening 34a of the needle, through the needle lumen, and
out the end opening 35a and into the patient.
In the embodiment illustrated in FIGS. 1, 2 and 3, the barrel 14
and the hub 27 are shown formed of a plastic material and are of
the disposable type. Also, the needle and hub assembly 18 is of the
removable type which is readily slipped onto or removed from the
forward end of the barrel.
Referring now to the embodiment illustrated in FIGS. 4, 5 and 6, a
hypodermic syringe 50 is shown including a housing or barrel 51
having a metal connector extension 52 connected to the forward end
thereof, a needle and hub assembly 54 coupled to the extension 52,
and a filter member 56 disposed in the barrel 51. The needle and
hub assembly 54 includes a hub 58 and a cannula or hypodermic
needle 59 having a pointed distal end with an opening 60, and a
proximal end 61 with an opening 62. Opening 62 is formed in the
side wall of the needle. As seen more clearly in FIG. 6, the
proximal end of the needle lumen, indicated at 64, is closed by a
metal plug 63 which may, for example, be welded or soldered
thereto. Hub 58 is provided with an internal annular bead or rib 65
disposed, in FIG. 4, between axially spaced external annular beads
or ribs 66 and 67 on the syringe extension 52.
The filter member 56 is shown as an annular disc wedged or
positioned in fluid-tight frictional engagement with the inner
walls of the barrel bore, indicated at 69, to divide the barrel
bore into proximal reservoir chamber portion 69a and a distal
chamber portion 69b. In this case, the filter member 56 is provided
with an opening 70 in aligned relation with needle 59 and which is
only slightly larger or substantially the same size as the outer
diameter of the needle. The needle 59 is slidable in the filter
opening 70 and substantially closes the opening to substantially
prevent fluid from flowing therethrough.
In FIG. 4, the hub and needle assembly 54 is positioned in a fluid
filtering position with the end 61 of the needle 59 disposed in
filter opening 70 to close the same and with the lumen opening 62
disposed within the forward chamber 69b and in direct fluid
communication therewith. Thus, if the end opening 60 of needle 59
is disposed in a fluid medicament and the plunger, indicated at 72
in FIG. 4, is moved rearwardly in bore 69, the negative pressure
produced thereby will draw fluid into the lumen of the needle 59,
out the opening 62, into forward chamber portion 69b, through the
filter member 56, and into the reservoir chamber portion 69a of the
barrel 51. The liquid medicament is thus filtered by filter 56.
When it is desired to dispense the filtered medicament in the
chamber portion 69a, for example, to inject the same into a
patient, the hub 58 is grasped and the assembly 54 is moved
leftwardly relative to the barrel 51 to move the annular bead 65
over the rearward annular bead 67 on the syringe extension 52 to
thereby position the hub and needle assembly 54 in a fluid
discharge position with needle in fluid-flow by-passing relation
with the filter member 56, as shown in FIG. 5. In this position,
the proximal portion of needle 59 is moved rearwardly in the
central opening 70 in the filter member 56 so that the proximal
opening 62 of the needle is rearward of the filter member and
disposed in direct communication with the reservoir chamber portion
69a. In this position, the filter opening 70 is also closed by the
needle 59. After the needle 59 is inserted into the patient, the
plunger is moved forwardly in barrel 51 to effect a positive
pressure which acts on the filtered medicament in the chamber
portion 69a to force fluid into the side-wall opening 62 in the
needle 59, through the needle lumen, and out the distal end opening
60 and into the patient.
In the embodiment illustrated in FIG. 7, a syringe 80 is shown
having a housing or barrel 81 and a piston assembly 82 with a
piston 83 disposed within the barrel chamber or bore 84. The
syringe has a lower conventional luer type end or tip 85 shown
integrally connected therewith and which receives a filter unit,
indicated generally at 87, which, in turn, has a needle and hub
assembly 88 connected thereto.
The filter unit 87 includes a barrel or housing 90 having a chamber
91 dividing it into proximal and distal chamber portions 91a and
91b, respectively, by a filter member 95 disposed in fixed relation
in the chamber 91. The housing 90 includes a proximal portion 90a
having a luer opening 96 which slidingly and frictionably engages
the luer tip or end 85 of the syringe barrel 81, and a distal
portion 90 b which receives the hub, indicated at 99, of the hub
and needle assembly 88.
The hub and needle assembly 88 includes a hypodermic or hollow
needle 100 having its proximal end opening indicated at 102
disposed in the distal chamber portion 91b, as shown in FIG. 7.
Assembly 88 is similar to assemblies 18 and 54 of the embodiments
illustrated in FIGS. 1 and 4 and includes an annular rib 103 on the
inner surface of the hub 99.
The filter member 95 is shown identical to the filter member 20 in
the illustrated embodiment of FIG. 1. Filter member 95 includes a
filter element 104 and a central seal member 106 sealing a central
opening therein. The seal member 106, which may be formed of rubber
or the like, is adapted to be pierced by the proximal pointed end
102 of the needle 100 after medicament fluid has been drawn through
filter unit 87 and into the barrel bore 84 of the syringe 80.
During the aspiration of fluid medicament into barrel bore 84,
fluid flows into the distal end of needle 100, through the lumen of
the needle, into chamber portion 91b, through filter element 104,
chamber portion 91a, and into the bore 84 of the syringe 80. Such
fluid flow is in response to negative pressures resulting from
movement of the piston 83 leftwardly, as viewed in FIG. 7.
When it is desired to discharge the filtered medicament from the
chamber 84, the hub and needle assembly 88 is moved rearwardly
until the annular bead of rib 103 or hub 99 has moved, from the
position shown in FIG. 7, over external annular beads, indicated at
108, on housing portion 90b of the filter unit 87. As the needle
and hub assembly 88 is moved leftwardly, the inner end opening 102
at the proximal end of the needle pierces the seal 106 and is
disposed in the proximal chamber portion 91a and in direct fluid
communication with the filtered medicament in the barrel of the
syringe 80. Upon movement of the piston 83 rightwardly, as viewed
in FIG. 7, the fluid pressure acting on the medicament is forced
into the opening 102 in the needle lumen so as to move fluid
through the lumen and out the distal end of the needle. Since
needle 100 is in by-passing relation with the filter member 95, the
flow of medicament from the barrel 84 to the distal end of the
needle, of course, by-passes the filter member.
The filter unit 87 may be utilized with a conventional syringe
barrel, such as of the type indicated at 81 in FIG. 7, and with a
conventional needle and hub assembly of the piercing type, such as
indicated at 88. Thus, the filter unit 87 can be stored separately
and used when desired, and may be used with conventional syringes,
and needle and hub assemblies.
In this illustrated embodiment, the housing of the filtering unit
87 is formed in two parts, 90a and 90b, which may be secured
together such as by heat sealing or welding after the filter member
95 has been disposed in the housing portion 90a. In the embodiment
illustrated in FIG. 7, the syringe barrel 81, the housing 90 of the
filter unit 87, and the hub 99 of the hub and needle assembly 88
are shown formed of plastic material, however, other materials,
such as glass and metal, may of course be utilized where desired.
Also, instead of utilizing the filter 95 and needle 100, a filter
and needle similar to those shown in the embodiment illustrated in
FIGS. 4, 5 and 6, may be used in the embodiment of FIG. 7 if
desired.
In some cases, the fluid medicament injection apparatus illustrated
herein may be operated by drawing unfiltered medicament into the
reservoir chamber portion while the needle is positioned in series
with proximal chamber portion but in by-passing relation with the
filter member (as in FIGS. 2 and 5). Then, relative movement
between the filter and needle is effected to locate the needle in a
position in fluid flow series relation with the filter, and distal
and proximal chamber portions (as in FIGS. 1, 4 and 7). In this
case, the medicament flows through the filter and then through the
needle in response to the positive pressure resulting from forward
plunger movement so that filtering is accomplished during the
discharge of medicament from the apparatus, for example, during the
injection thereof into a patient.
While there is shown and described preferred forms of the invention
herein, it will be understood by those skilled in the art the
various changes and modifications thereto may be without departing
from the true spirit of the invention, the scope of the invention
being defined only by the appended claims.
* * * * *