U.S. patent number 3,695,266 [Application Number 05/047,419] was granted by the patent office on 1972-10-03 for needleless sequential dosing syringe.
Invention is credited to Maurice G. Lussier.
United States Patent |
3,695,266 |
Lussier |
October 3, 1972 |
NEEDLELESS SEQUENTIAL DOSING SYRINGE
Abstract
This invention relates to a needleless syringe for the
application of a plurality of sequential doses of medicament in
rapid succession without reloading, wherein the driving force is a
pressurized fluid. BACKGROUND OF THE INVENTION This invention
relates to hypodermic syringes for injecting pharmaceuticals and
other liquids into tissues, veins or arteries, or onto the surface
of the skin and, more particularly, to syringes by which
pharmaceuticals and medicaments can be injected through the skin
without the aid of a skin penetrating needle. While needleless
syringes have widespread utility in the fields of medicine and
dentistry, such devices have been found to be particularly
advantageous in the administration of local anesthetic in
connection with dentistry. The insertion of needles into the mouth
tissue of the patient is painful, and because of the unweildly
construction of many conventional syringes, are awkward to operate,
which may result in additional pain or discomfort to the patient.
The needleless syringe, on the other hand, avoids the pain aspects
of the injection but introduces or retains other problems. For
example, a widely accepted type of syringe employs a spring as the
force-exerting means to project the medication; in this case the
anesthetic, from the syringe into the patient's tissue. A device of
the spring loaded type is described in U.S. Pat. No. 2,821,981. The
primary disadvantages of such devices are the bulkiness of the
syringe and the necessity of withdrawing it from the mouth to
withdraw the spring to its retracted position. Since several
injections are usually administered for dental treatments,
operation of such a syringe is time-consuming. Since the operator
must repeatedly remove the work area from his field of vision
during retraction of the piston, this may result in disposition of
the anesthetic in areas other than those desired. Various syringes
have been employed which avoid the problem of spring retraction by
employing a compressed gas as the driving force for expelling the
medication. For example, U.S. Pat. No. 2,645,223 discloses a
gas-actuated syringe wherein a rotatable ball valve releases the
pressurized gas to drive a piston against the medicament with
sufficient force to expel said medicament. A combination of lugs
and passages can be adjusted to determine the length of the
piston's travel and, thus, the amount of medicament expelled. A
similar device is shown in U.S. Pat. No. 2,605,763 wherein the
valving means employs a spring-loaded gas release mechanism.
However, the prior art devices suffered from a number of
deficiencies. For example, adequate valving means generally have
not been available to shut off the gas supply while a new supply of
medication is introduced into the syringe, or it may be difficult
or impossible to maintain sterile conditions in the syringe while
reloading the device. Thus, the utilization of prior art gas
actuated syringes has generally been limited to the use of a single
charge of gas to a single charge of medicament, and if one was
exhausted before the other, both must be discarded which is a
wasteful procedure. A novel device has now been found which is not
susceptible to the deficiencies of the prior art. SUMMARY OF THE
INVENTION A novel device has now been found which is comfortably
handled in accordance with conventional syringe from procedures,
with which physicians and dentists are readily familiar and which
will provide repeated and rapid discharges of the medicament
without withdrawing the device form the work area, e.g., the mouth.
Similarly, the gas chamber can readily be sealed off from the
propelling means and the medicament chamber to permit the opening
of the syringe and replacement of an exhausted charge of medicament
or a different kind of medicament. Conversely, if the propelling
gas supply is exhausted before all the medicament has been
expelled, the communication means between the gas supply chamber
and the rest of the syringe can be closed off and the gas supply
replenished. The means for determining the dosage can also be
readily exchanged without disturbing sterility of the medicament or
loss of propellant. Specifically, the novel device of the present
invention comprises a syringe having a housing, propellant fluid
containing and delivering means; a medicament chamber, a piston
adapted to be driven by said gas into the medicament chamber with
sufficient force to expell a quantity of said medicament, whereby
the increment of medicament delivered is determined by the distance
traveled by the piston, said distance being determined by the
spacing of teeth on the piston which engage and disengage stopping
means. More specifically, it has now been found that a plurality of
measured dosages of medicament can be delivered rapidly and
accurately by employing an elongated piston or driving means having
a plurality of opposed, offset teeth or steps which are alternately
engageable by holding means, preferably in the form of a pin
movable substantially perpendicular to the path of the piston,
whereby the actuation of the holding means to release the piston to
deliver a quantity of medication by releasing one step on the
piston, also serves to move said holding means into position to
engage the next following opposed, offset step which will move into
the engageable position with the holding means as the piston
advances, thus preventing the piston from traveling further than
the distance between said opposed steps. The distance between said
steps is determined with respect to the quantity of medicament to
be delivered. The above-mentioned holding means is adapted to be
rapidly moved back and forth by action of the fingers holding the
syringe thereby permitting the delivery of a number of dosages
rapidly by successively engaging and releasing the opposed offset
steps on the piston. Novel sealing means, including bleeding means,
permits the closing off of the gas supply portion of the syringe
and dismantling the syringe to replace the medicament supply or the
piston.
Inventors: |
Lussier; Maurice G. (Lynn,
MA) |
Family
ID: |
21948858 |
Appl.
No.: |
05/047,419 |
Filed: |
June 18, 1970 |
Current U.S.
Class: |
604/70; 604/71;
604/190; 222/471; 604/143; 604/210 |
Current CPC
Class: |
A61M
5/31595 (20130101); A61M 5/30 (20130101); A61M
5/2053 (20130101) |
Current International
Class: |
A61M
5/315 (20060101); A61M 5/30 (20060101); A61m
005/22 (); A61m 005/30 () |
Field of
Search: |
;128/173H,218R,218C
;222/471 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Gaudet; Richard A.
Assistant Examiner: Dunne; G. F.
Claims
I claim:
1. A device for injecting liquid medicament which comprises a
housing which includes:
pressurized fluid means;
means for retaining a medicament;
means for driving said medicament from said device, said
pressurized fluid means acting on said driving means;
said driving means comprising an elongated piston having a
plurality of opposed, offset teeth thereon; and
stopping means adapted to engage and disengage said teeth in
sequence, said stopping means comprising a pin perpendicular to
said piston and having a slot therein, said piston passing through
said slot whereby said teeth sequentially engage alternate edges of
said pin as said pin moves in reciprocating motion.
2. A device as defined in claim 1 which includes:
a pressurized fluid chamber;
propelling means adapted to be driven by said pressurized
fluid;
a medicament chamber;
said propelling means adapted to act on medicament retained in said
medicament chamber dispensing it from said device;
said propelling means comprising an elongated piston having a
plurality of opposed, offset steps thereon; and
stopping means adapted to alternately engage and disengage from
said steps thereby providing for incremental advancement of said
piston, said stopping means comprising a pin perpendicular to said
piston and having a slot therein, said piston passing through said
slot whereby said steps sequentially engage alternate edges of said
pin as said pin moves in reciprocating motion.
3. A device as defined in claim 2 which includes means for sealing
said pressurized fluid chamber from the rest of said device.
4. A device as defined in claim 1 wherein said pressurized fluid is
retained in a flask and said pressurized fluid chamber includes
piercing means for releasing fluid from said flask.
5. A device as defined in claim 1 wherein said medicament retaining
means comprises an ampule-receiving chamber and said piston is
adapted to exert dispensing pressure thereon.
6. A device as defined in claim 1 which includes a nozzle for
dispensing said medicament, said nozzle rotatable in a 360.degree.
arc.
7. A device as defined in claim 1 which includes a gas-tight
floating piston communicating between said elongated piston and
said pressurized fluid means.
8. A device as defined in claim 1 which includes pivotally mounted
finger holds adapted to act on said pin.
9. A device for injecting liquid medicament which comprises a
housing which includes:
pressurized fluid means;
means for retaining a medicament;
means for driving said medicament from said device, said
pressurized fluid means acting on said driving means;
said driving means comprising an elongated piston having a
plurality of opposed, offset teeth thereon; and
stopping means adapted to engage and disengage said teeth in
sequence;
said pressurized fluid means comprises a chamber retaining therein
a flask containing a gas under pressure; means associated with said
chamber adapted to pierce one wall of said flask to permit gas to
escape therefrom; said piercing means including sealing means
adapted to seal said chamber when detached from said device to
prevent substantial escape of gas therefrom; said sealing means
comprising a spring loaded plate adapted to be forced against the
aperture of said chamber closing said aperture by the pressure of
the gas in said chamber; venting means associated with said chamber
adapted to be actuated on said detachment; said piston being
contained in a housing and passing through a slot in a pin disposed
transversely to said piston and extending through opposed walls of
said housing; said teeth adapted to sequentially engage alternate
edges of said pin as said pin moves in reciprocating motion in
response to manual actuation thereof; a floating piston
intermediate said chamber and said piston, said floating piston
being substantially gas-tight; whereby said pressurized gas acts on
said floating piston which in turn acts on said piston, said piston
adapted to engage one e end of an ampule containing medicament;
piercing for said ampule associated with discharging means; nozzle
means associated with said discharging means, whereby said piston
upon advancing will displace a given amount of medicament from said
ampule, discharging said medicament from the device through said
nozzle.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of the syringe of the present
invention,
FIG. 2 is an enlarged cross-sectional view showing the central
portion of the syringe;
FIG. 3 is a fragmentary cross-sectional view taken along line
3--3;
FIG. 4 is a fragmentary cross-sectional view taken along line 4--4;
and
FIG. 5 is an enlarged cross-sectional view showing the delivery end
of the syringe.
DETAILED DESCRIPTION OF THE INVENTION
DETAILED DESCRIPTION OF THE INVENTION
The present invention is directed to a syringe, particularly
adapted for use as a needleless syringe, wherein repeated,
premeasured doses are rapidly delivered by said syringe.
Specifically, the syringe comprises pressurized fluid driving
means, preferably sufficient to impart velocities to the medicament
sufficient to inject said medicament through the tissues; racheted
piston means adapted to be driven by said fluid driving means; the
teeth on said piston being opposed and offset; engaging means for
said teeth comprising a pin having a slot therein, movable from a
first to a second position in reciprocating fashion and adapted to
alternately engage the teeth on the piston, thus permitting the
piston to advance the distance between adjacent opposed steps each
time said pin is actuated; wherein the distance between said teeth
determines the dosage delivered. The piston acts upon a chamber
containing medicament with sufficient velocity to expel a portion
of the medicament contained therein. Preferably, the medicament is
retained in a conventional sterile cartridge and does not contact
the surrounding chamber on the piston.
More specifically, the piston is disposed within the slotted pin,
and the slot and teeth so arranged that a tooth or step must engage
the pin at either end of the slot. Thus, while the pin engages one
step or tooth in a first position, and the pin is moved
perpendicular to the axis of the piston from said first position,
the first tooth will be disengaged, the pressurized fluid force on
the piston will advance the piston through the pin until the next
adjacent and opposed step engages the opposite side of the slot,
thus halting the forward motion of the piston until the pin is
again actuated by returning it to the first position repeating the
operation. A series of doses of medicament can be expelled by
moving said pin from a first to a second position to said first
position and so on, thus advancing the piston in a measured,
step-wise fashion. The quantity of medicament expelled is
determined by the distance between adjacent steps on the piston. A
piston with pre-selected distances between steps is selected for
employment with the syringe to deliver a pre-selected dosage of
medicament.
Preferably, the pin is actuated by the action of the fingers of the
operator alternately exerting pressure on finger holds on the
syringe which engage the slotted pin imparting the reciprocating
motion to said pin.
Turning to the drawing, FIG. 1 is a side elevational drawing of the
syringe 10 of the present invention showing body 11 which contains
rachet piston chamber 11a and medicament chamber 11b joined to 11a
at 11c; nozzle 12 shown for employment as a needleless syringe and
preferably rotatable in a 360.degree. arc, and pressurized fluid
chamber 13. The syringe is hand held by thumb hold 14 and opposed
finger holds 15 pivotally secured to body 11 by mounting means 16
and adapted to engage the ends of pin 17 as it protrudes from body
11, and alternately move said pin from a first to a second position
as the finger holds 15 are alternately moved towards and away from
body 11. Intermediate body 11 and pressurized fluid chamber 13 is
joining means 19 which contains puncturing means of the pressurized
fluid which is contained in a flask. Also contained therein and
which will be discussed below are venting means and sealing means
permitting the separation of the units without loss of the
pressurized fluid.
FIG. 2 illustrates a portion of pressurized fluid chamber 13,
chamber 11a and joining means 19. In the configuration shown, flask
60 containing gas under pressure has been punctured, the syringe in
the "open" attitude, i.e., gas is impinging on the driving means
and the syringe is thus operative.
As shown in FIG. 2, flask 60 has been inserted into chamber 13
through the end closed by cap 20. The engagement of joining means
19 and chamber 13 with sealing means 25 prevents any gas leakage.
As the flask 60 is urged downward by cap 20, it contacts piercing
means 26 comprising plate 27 and piercing cannula 28 which is
centered by means of spring 29.
When the contact between flask 60 and piercing means 26 has urged
piercing means 26 to its furthest point, i.e., when it contacts the
end of piston chamber 11a, the piercing cannula 28 punctures flask
60 releasing the pressurized gas contained therein. The pressurized
gas can then pass into chamber 40 through aperture 31 in the wall
of chamber 11a where it impinges on floating piston 41 which
frictionally engages the walls of chamber 40 in a gas-tight
relationship and which engages the upper end of piston 42 with
sufficient force to expel the medicament when a step on piston 42
is disengaged and acts on the medicament chamber.
Piston 42 has a plurality of opposed, offset teeth or steps 42
thereon adapted to engage an inner edge of pin 17 slidably mounted
in slot 50 in chamber 11a. Finger holds 15 are pivotally mounted
around points 17 on bracket 16 attached to chamber 11a.
The relationship of piston 42 to pin 17 is also shown in FIG. 3
which is a horizontal view taken along line 3--3, and in FIG. 4
which is a vertical view looking down on the syringe, along line
4--4. Piston 42 passes through slot 18 in pin 17 and engages the
pin at the edge of the slot. As pin 17 is moved horizontally, that
is in a direction transverse to the axis of chamber 40 and
direction of travel of piston 42, tooth 43 will disengage from the
edge of pin 17 and, because of the pressure exerted on it from
floating piston 41, will move through slot 18 until the next step,
on the opposite side of piston 42 engages the side of pin 17 thus
stopping the forward motion of piston 42. Piston 42, by virtue of
the driving force which has advanced it the described single step,
acts on the medicament to expel an amount from the syringe
corresponding to increment between steps. Thus, the distance
between steps will determine the dosage delivered, and pistons with
a variety of distances between steps can be employed
interchangeably depending upon the medicament employed and the
dosage desired.
As was described above, the flask 60 was inserted into chamber 13
and then screwed onto joining means 19 which was already attached
to body 11. Alternatively, the three pieces may be assembled in
several combinations. HOwever, once the fluid container is
punctured, joining means 19 cannot be removed from chamber 13
without loss of gas.
As stated above, the medicament may be replaced, piston 42
retracted to its starting position and the flask of pressurized gas
may be replaced without interfering with sterility or the
operativeness of the remaining portions of the syringe. For
example, in order to detach the pressurized driving means form the
syringe, for example, to replace the medicament and retract piston
42, chamber 13 and joining means 19 would be detached as a unit
from chamber 11a bby unscrewing threads 37. As joining means 19 is
being detached from chamber 11a, the force of the gas will force
plate 27 downward as chamber 11a is, in essence, being retracted,
until it engages sealing means 33, e.g., an O-ring, thus shutting
off the gas supply from the rest of the syringe and maintaining the
gas within the chamber 13. Upper sealing means 53 and lower sealing
means 52 prevent leakage of gas from the syringe during operation.
As joining means 19 is being detached from chamber 11a, venting
means 51 will pass upper sealing means 53, thus permitting residual
gas remaining in chamber 40 to be discharged to the atmosphere. No
gas will be lost from pressurized fluid chamber 13 because, as
stated above, plate 26 in association with sealing means 33 seals
off pressurized fluid chamber 13.
With the gas vented above floating from 41, medicament chamber 11b
may be detached form chamber 11a and piston 42 may be retracted
from its extended position by exerting a force against piston 42
moving it, as well as floating piston 41, up into chamber 40 where
it will be ready to again be used with a new charge of
medicament.
Floating piston 41 has been shown as a separate unit. It should be
understood that it may comprise an integral part of piston 42 if
desired. However, piston 41 must make a gas-tight engagement with
the walls of chamber 40, as by the O-ring shown in FIG. 2. If
pistons 41 and 42 are separate, it is only necessary to replace
piston 42 for dispensing different dosages.
FIG. 5 is a cross-sectional view of the lower portion or delivery
end of the syringe showing medicament chamber 11b containing
therein, in the embodiment shown, an ampule 65 containing
medicament 67 retained in walls of e.g., glass, and, on the lower
end, membrane 66 and on the upper end, piston type stopper 68
preferably of rubber and adapted to slidably engage the walls of
ampule 65 in response to pressure applied by actuating rod 45
mounted on the end of piston 42 and of such dimensions to fit
within the walls of ampule 65 as the medicament is expelled and
stopper 68 moves downward towards the opposite end.
As shown in FIG. 5, actuating rod 45 is shown as attached to piston
42 by screws. It should also be understood that actuating rod 45
may comprise an integral part of piston 42 or may be attached by
quick release means known to the art.
Medicament chamber 11b may be secured to the device by any suitable
means such as by screw threads or, preferably by bayonet joining
means for quick release. It should be noted that a gas-tight system
is not required since the pressurized gas is retained behind the
floating piston 41 and does not enter the part of the device
housing piston 42 or the medicament.
An ampule can be inserted into chamber 11b and the chamber rejoined
to the device. This action will cause membrane 66 to be punctured
by cannula 70. However, no medicament will be expelled from the
device until pressure is applied because of the extremely small
dimensions of perforated plate 71, which provides for the fine
spray expelled under sufficient pressure to penetrate human
tissues. After passing through plate 71, the medicament exits
through orifice 12a in nozzle 12, which is preferably rotatable in
a 360.degree. angle simplifying operation of the syringe.
The ampules or medicament containing cartridges, as described
herein, are conventional and known to the art.
The driving force has been described primarily in terms of a
pressurized or liquified gas. The term gas is intended to include
air, nitrogen, freon, carbon dioxide and the like. It should also
be understood that instead of retaining the fluid in a flask or
cartridge, as illustrated, suitable valving means may be mounted on
chamber 13 and pressurized directly with a suitable fluid from a
large source of said fluid.
The syringe of the present invention may be composed of any
suitable material capable of withstanding the pressures and
stresses involved. The preferred material is stainless steel.
* * * * *