U.S. patent number 3,729,003 [Application Number 05/114,423] was granted by the patent office on 1973-04-24 for variable dosage ampoule applicator.
This patent grant is currently assigned to Ampoules, Inc.. Invention is credited to Alfred A. Hurschman.
United States Patent |
3,729,003 |
Hurschman |
April 24, 1973 |
VARIABLE DOSAGE AMPOULE APPLICATOR
Abstract
A variable dosage ampoule applicator having an external
adjustment to vary the amount of medicament expressed from a
medicament-containing ampoule contained within the applicator. The
applicator has a hollow body with an ampoule mounting sleeve
adjustably threaded to one end of the body. The ampoule is
removably inserted within the sleeve and includes a cylindrical
sidewall closed at one end by a slidable plunger and at the other
end by a pierceable diaphragm. A hollow needle disposed within the
medicament chamber is fixed to the plunger with its pointed end
directed toward the pierceable diaphragm. The applicator includes a
force-applying head to depress the ampoule plunger. The
force-applying head has a fixed preselected stroke between a
retracted position and an extended position. By adjusting the
ampoule mounting sleeve, and therefore the ampoule, relative to the
stroke of the force-applying head, the degree of depression of the
ampoule plunger may be varied to thereby vary the volume of
medicament injected into the patient by actuation of the
force-applying head from its retracted position to its extended
position.
Inventors: |
Hurschman; Alfred A. (Hudson,
OH) |
Assignee: |
Ampoules, Inc. (Hudson,
OH)
|
Family
ID: |
22355095 |
Appl.
No.: |
05/114,423 |
Filed: |
February 11, 1971 |
Current U.S.
Class: |
604/138 |
Current CPC
Class: |
A61M
5/2033 (20130101); A61M 5/31551 (20130101); A61M
5/31591 (20130101); A61M 2005/206 (20130101) |
Current International
Class: |
A61M
5/20 (20060101); A61M 5/315 (20060101); A61m
005/20 (); A61m 005/28 () |
Field of
Search: |
;128/218D,218DA,218F,218R,216,173H,215,218P |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Gaudet; Richard A.
Assistant Examiner: McGowan; J. C.
Claims
What is claimed is:
1. A variable dosage ampoule applicator comprising a hollow body
and means for mounting thereon a medicament-containing hypodermic
ampoule having a depressible plunger and medicament-injecting means
adapted to inject a volume of medicament into a patient as a direct
function of the degree of depression of said plunger, said
applicator also comprising force-applying means including an
axially movable force-applying head slidably mounted on a normally
stationary shank, said force-applying head being mounted for
movement in the direction of said plunger for depressing the
plunger and having a pre-selected stroke between a first retracted
position and a second extended position relative to said hollow
body and means for driving said force-applying means, said shank
having stop means adjacent one end thereof for establishing said
second position, and means for adjusting the position of said
ampoule axially of said hollow body relative to both said first and
second positions of said force-applying means and relative to said
stop means to thereby vary the degree of depression of said plunger
and the volume of medicament injected by movement of said
force-applying means to its second position, and means for
adjusting the position of said stop means relative to said body to
thereby adjustably establish the stroke of said force-applying
head.
2. A variable dosage ampoule applicator according to claim 1,
wherein said means for adjusting the position of said stop means
includes a threaded connection between said body and said stop
means.
3. An ampoule and variable dosage ampoule applicator including a
hollow cylindrical body, a mounting sleeve threaded onto one end of
said body and being axially adjustable relative to said body, an
ampoule mounted within said mounting sleeve for adjusting movement
therewith; said ampoule having a cylindrical sidewall for a
medicament chamber, a diaphragm closing said chamber at one end of
said sidewall, a plunger initially slidably mounted in the other
end of said sidewall for closing the other end of said chamber and
having a hollow needle attached thereto so that a pointed end of
said needle is directed toward said diaphragm, and a medicament
contained within said ampoule; force-applying means including an
axially movable force-applying head slidably mounted on a normally
stationary shank which is, in turn, mounted on said cylindrical
body, said force-applying head having a stroke in axial alignment
with said plunger, spring means biasing said force-applying head
axially toward said plunger, releasable latch means retaining said
force-applying head in a first retracted position, said shank
having stop means limiting the stroke of said force-applying head
in a second extended position, said second extended position being
axially beyond the initial position of said plunger and toward said
diaphragm, whereby upon release of said latch means said
force-applying head will push said plunger toward said diaphragm so
that said needle will pierce said diaphragm and whereby said second
extended position may be varied relative to said cylindrical
sidewall by axially pre-adjusting the position of the threaded
sleeve relative to said cylindrical body to thereby vary the amount
of medicament expressed by said plunger through said hollow needle,
and means for adjusting the position of said stop means relative to
said body to thereby adjustably establish the stroke of said
force-applying head.
4. The variable dosage ampoule applicator according to claim 3,
wherein said means for adjusting the position of said stop means
includes a threaded connection between said body and said
shank.
5. The variable dosage ampoule applicator according to claim 4
wherein the stop means includes a screw having an enlarged head for
abutting coaction with said force-applying head at the end of its
stroke and the means for adjusting the position of said stop means
includes a threaded shank of said screw threadedly engaged in a
rod.
Description
BACKGROUND OF THE INVENTION
In many instances, it is necessary to vary a standard medicament
dosage depending upon the physical condition of the patient prior
to an injection. For example, approximately 25 per cent of all
diabetic patients using insulin therapy are considered to be
so-called "stable diabetics." Under stable conditions of diet,
physical and mental exertion, etc., such patients would normally
require a regular schedule of uniform dosages of insulin to
maintain a blood sugar balance. However, since they are generally
unable to control their living habits with precision, the majority
of these "stable diabetics" require minor variations up to plus or
minus 15 per cent of their standard dosage to maintain the blood
sugar balance. They commonly learn over a period of time to
diagnose their own variations in insulin requirements, either by
their own physical reactions to carelessness in dietary habits
and/or over-exertion, or by use of urinalysis, and become capable
of adjusting their insulin dosages accordingly. For example, a
patient who is standardized on 20 units of insulin per day may vary
his dosage between 17 and 23 units. Such a patient would purchase
insulin in 10 cc. vials and use a reusable or disposable syringe
calibrated in insulin units to make a subcutaneous injection. The
type of syringe commonly employed required him to withdraw the
proper insulin dosage from the vial and administer his
injection.
Disposable ampoules adapted to perform subcutaneous injections are
ideal devices for performing injections because of their
convenience and low cost. However, such ampoules normally are
pre-filled unit-dose devices and have not been widely accepted for
insulin treatment because of the diabetic's required variations
from standard dosages. Of course, it is possible to provide such
unit-dose ampoules in a variety of different sizes for
administering different dosages to cover normal variations from
standard dosages. This, however, is impractical from the standpoint
of the pharmaceutical manufacturer, since he would be required to
carry a greatly enlarged inventory, and such a large inventory may
present shelf-life problems for the drug contained therein.
Furthermore, the diabetic himself would have to stock a variety of
different sizes of the pre-filled ampoules.
In order to overcome these problems, it was proposed long ago to
provide a single ampoule containing a quantity of medicament
sufficiently in excess of a standard dosage to cover an expected
maximum dosage requirement. For example, a patient standardized on
20 units of insulin per day would be provided with an ampoule
containing 23 units of insulin. By use of an adjustable or variable
dosage applicator, the desired amount of insulin from the expected
maximum to the expected minimum may be injected by the patient.
Such a variable applicator is set forth in U. S. Pat. No. 159,192
to Leiter, granted in 1875. The applicator according to Leiter may
be adapted to inject different dosages by shortening or lengthening
the stroke of an applicator plunger. This is accomplished by
adjusting a nut on the plunger to limit the stroke of the plunger
to a predetermined portion of its maximum stroke from a fixed
starting position. However, in order to adjust the stroke of the
plunger, one must disassemble the Leiter device to gain access to
the adjusting mechanism. Furthermore, the adjusting nut of Leiter
is stopped by an end cap of the glass ampoule vial and,
consequently, the full force of a driving spring is transmitted to
the sidewall of the medicament-containing vial. Such force may tend
to shatter a glass vial during an injection.
A later proposal involving a variable dose injector is set forth in
U. S. Pat. No. 2,754,818 to Scherer. The Scherer patent relates to
a hypojet or needleless injector having a housing for a
force-applying member and an ampoule containing sleeve threaded
onto one end of the housing. In its initial position, the
force-applying member of Scherer contacts a head portion of the
ampoule. In order to vary the dosage, the threaded sleeve is turned
so that the force-applying member pushes the ampoule head toward a
jet nozzle to expel a metered amount of fluid from the nozzle prior
to the injection. After such an adjustment is effected, the
force-applying member is triggered to expel the remaining contents
of the ampoule into the patient to thus perform an injection. After
such an adjustment is made, however, the stroke of the
force-applying member of Scherer is limited by the end portion of
the applicator adjacent the nozzle. Thus, substantial reinforcement
must be provided at the jet end of the applicator to resist and
limit the stroke of the force-applying member.
SUMMARY OF THE INVENTION
This invention overcomes many of the foregoing prior art problems
relating to variable dosage applicators by providing a variable
dosage applicator which permits preselected variations in dosages
by a simple, externally located adjusting mechanism. To this end,
the applicator is provided with a hollow body or sleeve having
mounting means for retaining a medicament-containing hypodermic
ampoule therein. The ampoule has a depressible plunger and a
medicament-injecting means and is adapted to inject a volume of
medicament into a patient as a direct function of the degree of
depression of the plunger. The applicator also includes a
spring-biased force-applying member mounted on the body for
movement in the direction of the plunger for depressing the
plunger. The force-applying member has a preselected stroke between
a first retracted position and a second extended position relative
to the hollow body. The position of the ampoule may be adjusted
relative to the first and second positions of the force-applying
means by a threaded connection between the ampoule mounting body
and means mounting the force-applying member. The stroke of the
force-applying member is limited in its second or extended position
by a stop means which does not transmit force to the sidewall of
the ampoule. Furthermore, the stop means limits the stroke of the
force-applying member to prevent contact between the force-applying
member and the medicament-injecting end of the ampoule so that that
end of the ampoule need not be reinforced by portions of the
applicator. This latter feature permits easy installation and
removal of the ampoule.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view of a variable dosage applicator
according to this invention.
FIG. 2 is an enlarged, cross-sectional view of the applicator, the
plane of the section being indicated by the line 2--2 in FIG. 1,
showing an ampoule mounted therein, partly in section.
FIG. 3 is a bottom end view of the applicator.
FIG. 4 is a cross sectional view, the plane of the section being
indicated by the line 4--4 in FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, a variable dosage ampoule applicator
10 is illustrated. The applicator 10 includes a hollow body 11
having a threaded end portion 12. An ampoule mounting sleeve 13 is
threaded onto the portion 12 and, as may be seen most clearly in
FIG. 3, includes an enlarged end portion 14 having diametrically
opposed slots 15 and 16 extending axially therethrough. The slots
15 and 16 respectively communicate with channels 17 and 18 in the
enlarged end portion 14 and respectively receive lugs 19 and 20
extending radially from an annular retaining clip 21. The channels
17 and 18 extend in a clockwise direction from the slots 15 and 16
and taper radially inwardly toward the inner cylindrical sidewall
of the sleeve 13. Thus, the clip may be removably retained in the
sleeve 13 by inserting the lugs 19 and 20 into the slots 15 and 16
and turning the clip in a clockwise direction until the lugs
frictionally engage the inwardly tapering sidewalls of the channels
17 and 18.
The retaining clip 21 is a component of an ampoule assembly 22
which is inserted into the open end of the applicator sleeve 13
with the lugs 19 and 20 moving through the slots 15 and 16. Turning
the clip in a clockwise direction then moves the lugs 19 and 20
into the channels 17 and 18 to retain the ampoule assembly in the
mounting sleeve 13.
The ampoule assembly 22 is more fully described as one embodiment
of the copending application of Alfred A. Hurschman and Thomas P.
Schiller, Ser. No. 114,493, filed Feb. 11, 1971, and includes a
cylinder 23 which is preferably made from transparent glass tubing.
One end of the cylinder 23 has a radially extending bead 24 which
is received within an annular groove 25 in the clip 21 and which,
together with a radially inwardly extending flange portion 26 of
the clip 21, clamps a diaphragm 27 against the lower end of the
cylinder 23.
The diaphragm 27 may be molded from rubber, and is preferably
shaped to function in accordance with the teachings of U. S. Pat.
No. 3,094,988, granted June 25, 1963, to Dunmire. The diaphragm 27
includes an outer annular portion 28, a thick, elongated, centrally
located needle guiding and liquid sealing gland 29, and a
relatively thin, flexible, corrugated, intermediate portion 30
connecting the gland 29 and the outer portion 28 to permit relative
axial movement thereof. A needle passage 31 extends axially into
the upper end of the gland 29 from the inside of the ampoule and
terminates short of the opposite, lower end of the gland so as to
leave a thin, easily puncturable wall 32 closing the bottom of the
passage 31. Alternatively, preforming the needle passage 31 may be
omitted during manufacture of the diaphragm 27, in which case the
pointed end of the needle is forced into the gland 29 to the proper
depth during assembly of the ampoule.
The other end of the cylinder 23 is closed by a rubber plunger 33
which, together with the diaphragm 27 and the cylinder 23, defines
a medicament and needle chamber 34.
Entirely enclosed within the chamber 34 is a hypodermic needle 35,
which preferably is of the type disclosed in U. S. Pat. No.
3,173,200 to Dunmire et al. A generally circular base or butt end
36 of the needle 35 is mounted on the plunger 33 so that the needle
cannula 37 extends axially downwardly in the cylinder 23 with its
pointed end 38 received within the axial recess 31 in the diaphragm
gland 29 in position to be forced through the thin end wall 32
thereof. An opening (not shown) is provided in the butt end of the
needle cannula 37, adjacent the base 36 of the needle, for free
flow of medicament from the chamber 34 into the butt end of the
needle cannula and through the cannula to the pointed discharge end
38 thereof. The chamber 34 is substantially completely filled with
a fluid medicament.
As may be seen most clearly in FIG. 4, the inwardly extending
flange portion 26 of the clip 21 forms a recessed, concave end
surface which causes the skin of the patient to stretch and dome
upwardly as the clip 21 is pressed against the skin of the patient.
As is more fully described in U.S. Pat. No. 3,236,237 to Dunmire,
it appears that the stretched skin, becoming tense, resists any
substantial identation by the gland 29 of the ampoule 22, and
thereby forces the gland 29 axially inwardly toward the pointed end
38 of the needle 35 while the ampoule body is restrained against
upward movement by the lugs 19 and 20.
The fluid medicament is injected into a patient by pressing the
clip 21 and diaphragm gland 29 against the skin of a patient and
forcing the ampoule plunger 33 downwardly toward the diaphragm 27
so that the needle 35 pierces the puncturable wall 32 to thereby
force medicament from the chamber 34 through the needle and into
the patient as the needle enters the patient and the volume of the
chamber 34 is reduced.
In the illustrated embodiment of this invention, a force-applying
means of the applicator for moving the ampoule plunger 33 includes
a force-applying head 40 having a bore 41 and a counterbore 42
therethrough. The head 40 has an enlarged cylindrical portion 43 at
one end and a reduced cylindrical portion 44 at its other end. The
cylindrical portion 43 forms a loose sliding fit with the inner
sidewall of the hollow applicator body 11. The reduced cylindrical
portion 44 has an outside diameter which is adapted to be received
within the ampoule cylinder 23 and is in axial alignment with that
cylinder in the assembly.
The force-applying head 40 is slidably mounted on a retaining screw
50 which has a shank 51 extending through the bore 41 and
counterbore 42 and a head portion 52 which is adapted to be
received within the counterbore 42 and limit downward movement of
the head 40 by engaging a shoulder 53 between the bore 41 and the
counterbore 42. The retaining screw 50 is threaded into the end of
a rod 55. Desirably, a locking insert (not shown) is provided on
the threaded end of the screw 50 to insure a frictionally tight
threaded fit between the screw 50 and the rod 55. A spring 56
surrounds the rod 55 between the force-applying head 40 and a
bushing 57 which is pinned to the rod 55. The bushing 57 insures
that the rod 55 is in a proper axially extending position. The rod
55 has an enlarged cylindrical portion 58 which is connected to a
cocking lever 59 by a toggle link 60. The cocking lever 59 is
pivotally connected to the applicator body 11 by a pin 61.
The force-applying head 40 is retained in a retracted position
illustrated in FIG. 2 by a plurality of locking balls 62. The
locking balls are retained in openings 63 in the hollow body 11 by
a firing ring 64 so that the locking balls engage a shoulder 65
between the portions 43 and 44 of the head 40. To release the head
40 from its retracted position, the firing ring, which forms a
sliding frictional fit with the body 11, is pushed downwardly
toward the mounting sleeve 13 until the balls 62 are forced into an
annular recess 66 in the ring 64 to thereby release the shoulder 65
and the head 40. The head 40 is thereupon driven downwardly by the
spring 56, first into engagement with the ampoule plunger 33 and
then on to an extended position. The extended position of the
force-applying head 40 is determined by engagement of the head
portion 52 on the screw 50 with the shoulder 53.
By driving the ampoule plunger 33 downwardly in this manner, the
needle 35 pierces the diaphragm 27 and the chamber 34 is reduced in
volume to force the medicament through the needle 35 and into the
patient. The volume of medicament injected into the patient is a
direct function of the degree of depression of the ampoule plunger
33 by the force-applying head 40. Since the stroke of the head 40
is constant, the degree of depression of the plunger 33 may be
varied, to thereby vary the volume of medicament injected, by
turning the ampoule mounting sleeve 13 in a clockwise direction to
increase the dosage and by turning the sleeve 13 in a
counterclockwise direction to decrease the dosage.
As may be seen in FIG. 1, the body 11 may be provided with a
pointer mark 70 and the sleeve 13 may be provided with indicia 71
to indicate a standard dosage and plus or minus variations from
standard. By pre-adjusting the retaining screw 50 in the factory,
the stroke of the head 40 may be calibrated to, for example, a
20-unit standard dose when the sleeve 13 is in the position
illustrated in the drawings.
After an injection has been effected, the applicator 10 may be
reset for another injection by removing the spent ampoule, raising
the cocking lever 59 so that the head 40 is drawn upwardly,
reseating the locking balls 62 in their illustrated position by
moving the firing ring 64 back to its illustrated position, and
then compressing the spring 56 by moving the handle 59 back to its
original position.
The invention is not restricted to the slavish imitation of each
and every detail set forth above. Obviously, devices may be
provided which change, eliminate, or add certain specific details
without departing from the scope of the invention.
* * * * *