Abstrict There is disclosed a precharged disposable syringe consisting of
a housing having a central aperture through which extends an actuator
button to contact an internal piston mounted over a medication ampoule
contained in the housing. The ampoule includes a dependent hypodermic
needle and the ampoule is slightively mounted in the housing for
movement between a recessed position where it is totally contained
and supported within the housing and an extended position with the
dependent needle projecting out of the housing. An actuator spring
is located in the housing and is compressed and biased to move the
piston and the ampoule into the projected position. Medication is
discharged by the mechanically coupled actuator button and piston.
The actuator button and piston is locked for safety with a dent
and plastic ring.
Claims What is claimed is:
1. A disposable, subcutaneous injection syringe which comprises:
a. a cylindrical housing having an outer diameter greater than
its length and having a central, cylindrical well, a first aperture
in its bottom wall and a second aperture in its top wall;
b. a cylinder having an outer diameter to be received in said cylindrical
well of said housing and received therein for sliding movement between
said apertures, a through bore in the bottom wall of said cylinder
and a hypodermic needle permanently mounted therein, and a piston
slidably received in said cylinder;
c. a dispenser carriage mounted in said housing and moveable therein
through an axial distance less than said outer diameter of said
cylinder, between retracted and extended positions;
d. a trigger button carried on said carriage and projecting through
said second aperture;
e. means coupling said piston to said carriage;
f. cylinder retraction means within said housing to maintain said
needle withdrawn in said housing;
g. a single actuator spring received within said housing and bearing
against said cylinder to extend said needle through said first aperture
in the bottom wall of said housing;
h. a single detent, which engages said carriage in its retracted
position and restrains its movement in said housing; and
i. a sterile seal cover extending across said first aperture.
2. The syringe of claim 1 wherein said detent includes an annular
groove about said actuator button and a snap ring engaged in said
annular groove and bearing against the top wall of said housing.
3. The syringe of claim 2 wherein said carriage includes an annular
flange within said housing and wherein said actuator spring is biased
between the inside top wall of said housing and said annular flange.
4. The syringe of claim 3 wherein said carriage bears, on its undersurface,
a boss which is received within said cylinder and which abuts against
said piston.
5. The syringe of claim 4 including a medication within said cylinder.
6. The syringe of claim 1 including a protective sheet material
overlying said seal cover and bonded thereto by a peelable, pressure
sensitive adhesive.
7. The syringe of claim 6 wherein said pressure sensitive adhesive
includes an antiseptic agent.
8. The syringe of claim 6 wherein said pressure sensitive adhesive
includes a tacifier agent, rendering the underside of said syringe
tacky upon removal of said protective sheet material.
9. The syringe of claim 1 wherein said cylinder retraction means
is a helical coil spring which is received between the bottom wall
of said cylinder and the bottom wall of said housing.
10. The syringe of claim 1 including a cup-shaped cap having an
inside diameter slightly greater than the outside diameter of said
housing and received over an end of said housing, and wherein said
housing is of the same outside diameter at each of its ends, whereby
said cap can be placed over the top wall end of said housing prior
to use of said syringe, and can be reversed and placed over the
bottom wall end of said housing after use of said syringe.
11. The syringe of claim 10 wherein said housing has an annular
rim about its mid-portion and said cap seats against said annular
rim.
12. The syringe of claim 1 including a protective sheet material
overlying said seal cover and bonded thereto by a peelable, pressure
sensitive adhesive.
13. The syringe of claim 1 wherein said pressure sensitive adhesive
includes an antiseptic agent.
14. The syringe of claim 12 wherein said pressure sensitive adhesive
includes a tacifier agent, rendering the underside of said syringe
tacky upon removal of said protective sheet material.
15. The syringe of claim 1 wherein said cylinder retraction means
is a helical coil spring which is received between the bottom wall
of said cylinder and the bottom wall of said housing.
16. A disposable, subcutaneous injection syringe which comprises:
a. a housing having a first aperture in its bottom wall and a second
aperture in its top wall;
b. a cylinder received in said housing mounted in said housing
for sliding movement between said apertures, a through bore in the
bottom wall of said cylinder and a hypodermic needle permanently
mounted therein, and a piston slidably received in said cylinder;
c. a dispenser carriage mounted in said housing and moveable therein
between retracted and extended positions;
d. a trigger button carried on said carriage and projecting through
said second aperture;
e. means coupling said piston to said carriage;
f. cylinder retraction means within said housing to maintain said
needle withdrawn in said housing;
g. an actuator spring received within said housing and bearing
against said cylinder to extend said needle through said first aperture
in the bottom wall of said housing;
h. a detent engaging said carriage in its retracted position and
restraining its movement in said housing;
i. a sterile seal cover extending across said first aperture; and
j. an annular chamber within said housing, and an internal passageway
communicating between said annular chamber and said cylinder, above
said piston.
17. The syringe of claim 16 wherein said annular chamber has an
external port sealed with a check valve to permit air pressurization
of said annular chamber and wherein said internal passageway includes
frangible valve means.
18. The syringe of claim 17 wherein said internal passageway includes
an annulus surrounding said cylinder, and said frangible valve means
is an annular ring seated in said annulus.
19. The syringe of claim 18 wherein said cylinder has an annular
groove about its outer wall and said annular ring is seated therein
to also function as said detent to restrain movement of said cylinder
in said housing.
20. The syringe of claim 19 including a knife carried on the underside
of said actuator button immediately above said frangible annular
ring.
21. The syringe of claim 16 including a cup-shaped cap having an
inside diameter slightly greater than the outside diameter of said
housing and received over an end of said housing, and wherein said
housing is of the same outside diameter at each of its ends, whereby
said cap can be placed over the top wall end of said housing prior
to use of said syringe, and can be reversed and placed over the
bottom wall end of said housing after use of said syringe.
22. The syringe of claim 21 wherein said housing has an annular
rim about its mid-portion and said cap seats against said annular
rim.
Description BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a hypodermic medicinal injector and,
in particular, to a hypodermic syringe which is safe and capable
of one time use by patients, handicapped, totally blind or aged
persons and children.
2. Brief Statement of the Prior Art
Various devices have been marketed for automated injection of medication.
A currently marketed system under the trade name Medi-Jector Easy
is promoted as a needle-free, insulin injection system. While this
device avoids the use of injection needles, it is intended for use
by medically trained personnel to maintain proper sterility, and
it is not a disposable injection system that can be readily used
by patients, or incapacitated persons.
Another device which has been recently introduced is marketed under
the name Inject-Ease. This device uses a hypodermic needle and has
interchangeable spacer rings to control the depth of needle penetration.
None of the devices currently marketed provide a disposable needle
type syringe for application of medication which is safe, sterile
and is adaptable for use by patients, including children and handicapped
and elderly patients. In many applications, there is no current
substitute for administration of medication by medically trained
and skilled persons, since there is no syringe which heretofore
has been available with accurately measured dosages of medication,
and which can be used by the patient. Thus, diabetic patients, or
patients suffering chronic allergies, must be dependent upon receiving
medical attention and care for administration of medication.
A syringe for use by patients must be disposable, with a design
which will prevent reloading, thereby avoiding misuse of the syringe
and the possibility of cross infection with agents such as AIDS
viruses. The hypodermic needle of the syringe should be totally
protected from contamination, and the syringe should be capable
of mass production, thereby insuring its low cost. It is a desirable
objective, at this time, to supply the syringe with variable size
needles from 1/8 to 1/4 inch and of 23 to 30 gauge, for pediatric,
adults and obese patients. It is also an objective to provide a
syringe which is preloaded by a licensed pharmaceutical company,
insuring sterility and accuracy of dosage and strength of the medication.
BRIEF STATEMENT OF THE INVENTION
This invention comprises a pre-charged, disposable syringe capable
of use by patients. The syringe includes a housing with a cover
having a central aperture which receives an actuator button. The
actuator button extends to an internal piston which is mounted over
a medication ampoule. The ampoule has a dependent hypodermic needle
which is slidably received in the housing for movement between recessed
and projected positions. In its recessed position, the ampoule is
totally contained and supported within the housing, and in its projected
position, the hypodermic needle projects out of the housing. The
housing contains an actuator spring, which is compressed and biased
to move the piston and the ampoule into its projected position.
The medication is discharged from the ampoule by the mechanically
coupled piston, or by the release of air from an internal air pressure
chamber. The actuator button is locked for safety with a detent
and plastic ring and is covered with a protective, removable cap
to prevent accidental or unintended injection of the medication.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described with reference to the figures of
which:
FIG. 1 is an exploded perspective view of the air activated embodiment
of the invention;
FIG. 2 is an elevational sectional view of the embodiment of FIG.
1 fully loaded in a static, preactivated state;
FIG. 3 is a partial, elevational sectional view of the embodiment
of FIG. 1 is its discharged state;
FIG. 4 is a perspective view of the assembled and loaded syringe
of the invention;
FIG. 5 illustrates removal of the protective tape from the underside
of the syringe;
FIG. 6 is a view of the syringe, uncovered, and in a position to
inject its medication;
FIG. 7 is a view of the syringe after use, with the cover replaced
on its undersurface for disposal;
FIG. 8 is an elevational sectional view of a spring activated mechanism,
in a static, preactivated state; and
FIG. 9 is an elevational sectional view of the device of FIG. 8
is its discharged state.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to FIG. 1 the invention is illustrated in exploded
view. The particular embodiment illustrated in FIG. 1 is the air
activated device. The device has a housing 10 which is preferably
cylindrical of relatively low height or elevation, and has a central
cavity 12 which receives the operating mechanism. The central cavity
12 has an internal well 14 with a right-angle, vertical cylindrical
wall 16 which slidably receives a cylindrically shaped ampoule member
18. The ampoule member 18 has a hypodermic needle 22 that extends
through its under surface and communicates with the medication chamber,
described in greater detail with reference to FIG. 2. An annular
groove 26 is provided about the outer side wall 28 of the ampoule
18 which is engaged by a sealing plastic ring (shown in FIG. 2).
The upper end of the sidewall of the ampoule 18 has an annular recess
32 which serves as a chamber for housing a compression spring (also
shown in FIG. 2). The actuator button 33 has a central upright boss
34 which is received in the central aperture 36 of the cover 40.
The button 33 and has a circular base 44 which carries, on its undersurface,
a knife 42 having a circular blade.
Referring now to FIG. 2 the invention will be described in greater
detail. As shown in FIG. 2 the housing 10 has an outer annular
chamber 43 which is the air supply chamber for the mechanism. A
fill port 46 is provided in the upper wall of the air chamber and
this port 46 communicates with an aligned aperture 48 in the cover.
A pneumatic valve 50 is inserted in the aligned aperture 48 and
fill port 46. This valve 50 is of a general grommet-shape with a
through passage 52 that is normally sealed by the resilient deformation
of the valve member under the internal pressure within the air chamber.
The internal air chamber communicates with the interior, medication
chamber 24 through a valve 54 which is sealed by a plastic ring
56. The valve has an annular seat 58 and is entirely covered by
this plastic ring seal 56. The seal 56 is received in annular groove
26 about the ampoule member 18 and thus also serves as a detent
to restrain the ampoule member 18 and needle 22 within the housing.
Seated within the medication chamber 24 is the cylindrical cup-shaped
ampoule member 18 which supports the hypodermic needle 22 on its
under surface. The hypodermic needle 22 is aligned with a central
through aperture 60 in the bottom wall 62 of the housing 10 and
is of sufficient length that when the ampoule member 18 is in its
illustrated, retracted position, the hypodermic needle 22 is withdrawn
from this aperture 60. The ampoule member 18 has sufficient travel
within the housing 10 to project the needle 22 through the aperture
60 and a predetermined distance into the tissue of the patient.
The actuator button 33 has a central raised boss 34 that extends
through the central aperture 36 of the cover 40. The button 33 is
enclosed within a protective cover 38 which seats against an annular
rim 39 about the mid-portion of the housing 10. The cover 38 can
be sealed to the housing by a tear tape, if desired. The button
33 supports, on its undersurface, a knife 42 with a circular blade.
The knife blade has a sharp circular cutting edge 66 which is aligned
with the plastic ring 56 so that it will puncture this plastic ring
and permit the discharge of the pressured air from the annular air
chamber 43 past the valve and into the ampoule chamber. The knife
also has a circular groove 67 which communicates with a passageway
69 that extends into communication with the internal chamber 24
of the ampoule member 18.
The ampoule member 18 has an annular well 32 in its upper edge
which provides a chamber for the actuator spring 70. The actuator
spring 70 is a compression coil spring biased between the undersurface
of the button 33 and the bottom wall of the annular well 32. This
spring has sufficient strength and resiliency to advance the ampoule
member 18 instantaneously upon release of the detent, previously
described, and extend the hypodermic needle 22 through the frangible
sterile tape 72 on the undersurface of the housing and into the
patient's subcutaneous space. The extended positions of the ampoule
member 18 and needle 22 are shown in FIG. 3. This extension of the
ampoule member 18 and hypodermic needle 22 occurs sufficiently rapidly
to precede the application of air pressure through circular groove
67 in the knife 42 and the passageway 69 of the button. Thus the
needle 22 is extended before air pressure is applied to the ampoule
74 contained within the ampoule chamber 24. The ampoule 74 is formed
by an elastic balloon which is received within and sealed to the
inner walls of the ampoule chamber, containing medication 78 within
its sealed interior. The air pressure supplied by the air chamber
43 through the air valve 54 and into the ampoule chamber is sufficient
to collapse the medication balloon and inject the medication 78
contained within the balloon into the patient.
The undersurface of the housing 10 has a frangible sterile tape
72 which is permanently bonded to the housing, and which overlies
the through aperture 60 and an overlying, protective sterile tape
80. The protective overlay tape 80 is bonded to the housing and
the sterile tape 72 with a pressure sensitive adhesive to permit
its removal from the injection device immediately prior to use.
FIG. 4 illustrates the hypodermic syringe of the invention as it
would be received by the patient. The syringe is preloaded with
a precisely measured dosage of medication and has the proper selection
of needle size for the patient. All of this information can be coded
on the syringe itself. The protective cover 38 overlies the actuator
button 33 and must be removed by the patient for access to the
button. As shown in FIG. 5 the patient or user will first remove
the protective overlay tape 80 exposing the underlying frangible,
sterile tape. As shown in FIG. 6 the patient will then position
the syringe against a suitable skin surface. Preferably, the undersurface
of the housing and the sterile tape 72 is coated with an antiseptic
pressure sensitive adhesive so that, when placed on the skin of
a patient, the undersurface of the device will disinfect and be
slightly tacky and will stick to the skin of the patient. The patient
then depresses the actuator button 33 breaking the detent of the
plastic ring 56. This will release the spring 70 to advance the
knife 42 through the plastic ring 56 and permit the ampoule member
18 to be ejected into its extended position. The air pressure which
is also released from the annular air chamber 43 will fill the ampoule
chamber 24 raising its internal pressure sufficiently to eject
the medication from the ampoule 74. Once the injection is completed,
the patient removes the device which is disposed as it cannot be
readily reloaded for reuse. For this purpose, the protective cover
38 which was removed from over the actuator button, is replaced
on the underside of the syringe, totally enclosing the needle 22
as shown in FIG. 7.
Referring now to FIG. 8 the alternative embodiment of the invention
will be described. As there illustrated, this device 82 has a cylindrical,
cup-shaped housing 84 having an outer wall 86 defined by a right-angle
cylindrical wall, and a central lesser diameter well 88. The bottom
wall 90 of the housing 84 has a central through aperture 92 which
slidably receives the hypodermic needle 94. The ampoule member 96
is a cylindrical cup-shaped member which contains medication 98
and which also receives a slidable piston 100. The piston 100 engages
the inside wall of the cylindrical member 96 in a sliding seal which
prevents leaking of the medication from the ampoule member 96. The
ampoule member 96 is resiliently biased into its retractable position
by a helical coil spring 102 which is seated in the central well
88 of the housing and which is collapsed when the ampoule member
96 is driven into its extended position.
The actuator button 104 is slidably received in a central aperture
106 of the top cover 108. The actuator button 104 is restrained
to this cover by a detent 112 formed by an annular groove 114 about
its outer, upper wall in which is seated a resilient clip washer
116. The button 104 has a cylindrical skirt 118 and a single, outwardly
flared flange 120. The cover 108 has a central inwardly and downwardly
dependent skirt 122 which receives the cylindrical skirt 118 of
the actuator button 104.
A cylindrical boss 124 is downwardly dependent from the undersurface
of the button 104 and has a diameter to permit it to be received
within the ampoule member 96. The boss 124 is immediately above,
and attached to, the piston 100 which is slidably contained within
the ampoule member 96. An actuator spring 128 in the form of a compression
coil spring is resiliently biased between the undersurface of the
cover and the upper surface of the flange of the actuator button.
When the device is in its armed and loaded condition as illustrated
in FIG. 8 the actuator spring 128 is compressed.
In use, the patient removes the protective overlay tape 130 from
the undersurface of the device, in the manner previously described
and illustrated in FIG. 5. Preferably, the undersurface of the device
has an antiseptic, pressure sensitive coating permitting its application
to the skin of a patient. In this position, the device is ready
for injection of the medication which is contained within the ampoule
member 96. The patient presses on the actuator button 104 sufficiently
to override the resilient detent of the circular clip washer 116.
This permits the actuator spring 128 to be released, forcing the
ampoule chamber 96 outwardly into its extended position, which is
shown in FIG. 9. In this position, the ampoule needle 94 projects
through the skin of the patient. When the ampoule chamber 96 bottoms
against the bottom wall 90 of the central well 88 the actuator
spring 128 continues the travel of the actuator button, and advances
the piston 100 through the ampoule chamber 96 ejecting the medication
98 in this chamber through the hypodermic needle 94 into the patient.
The resilient bias of the retraction spring 102 is designed to be
less than the force required for slidably advancing the piston 100
in the ampoule chamber 96 thereby ensuring that the medication
is not prematurely ejected from the ampoule chamber.
Special Advantages of the Invention
The ejection operation of both embodiments of the invention is
smooth and continuous with the initial advance of the ampoule chamber
and hypodermic needle which eject with sufficient force for the
needle to penetrate the skin of the patient. This initial movement
is immediately followed by the continuous injection of the medication
contained within the ampoule chamber. Since the device of this invention
can not be readily reloaded it is safe for prescription as a disposable,
single use medication. The device is very safe for use by patients
and since it can only be used once, there is no possibility of passing
a contagious or infectious diseases such as AIDS. The device can
be provided with variable capacity and with needles of varied sizes
and lengths suitable for pediatric use, or use by adults or obese
persons.
Since the device can be readily used by the patient, it is ideally
suited for diabetic control, for anaphylatic shock, such as encountered
with hypersensitive or allergic individuals, e.g., for dispensing
of medication for bites by snakes, bees, insects, etc. As the device
is entirely pre-loaded, little physical ability and judgement is
required of the patient and the device can be used by children,
handicapped persons or persons whose judgement or dexterity has
been temporarily impaired by shock.
The device can be used to inject only vertically as it has a large
exterior surface that is applied to the skin which is relatively
large compared to the depth of the needle. Accordingly the device
cannot be used for intravenous injections which, of course, require
skilled and licensed personnel.
Preferably, the device is provided with a transparent structure,
e.g., formed of transparent plastics, thereby readily permitting
observation of the contents of the ampoule. The actuator button
can be suitably color-coated, e.g., preferably molded of a red colored
plastic. In its preferred embodiment, as shown in FIG. 3 the device
also includes a protective cover 132 which is mounted about the
side wall 134 of the housing 84 and which engages against an annular
rim 136 that extends about the periphery of the housing, preferably
at its mid-portion. This permits the cover to be reapplied over
the opposite end of the housing after use, thereby encasing the
needle in a protective chamber when the device is disposed.
The extreme compactness of the device and its low profile stabilizes
the device when used by the patient. Additionally, the low profile
and compactness of the injection device greatly aids packaging and
distribution by the pharmaceutical supply house.
All of the component parts of the injection device can be fabricated
of readily available materials such as plastics using injection
molding techniques for mass production. The device can be marketed
with significantly lower costs than conventional syringes. The device
can be assembled and preloaded with measured amounts of medication
under sterile conditions by the pharmaceutical supply house and
can be sealed with the frangible sterile tape and the protective
overlay tape, isolating the medication from contact with the external
environment. |