U.S. patent application number 10/555742 was filed with the patent office on 2007-07-19 for needle free hypodermic injector and ampule for intradermal, subcutaneous and intramuscular injection.
Invention is credited to Conrad Anstead, Robert Brant, John Deslierres.
Application Number | 20070167907 10/555742 |
Document ID | / |
Family ID | 34891108 |
Filed Date | 2007-07-19 |
United States Patent
Application |
20070167907 |
Kind Code |
A1 |
Deslierres; John ; et
al. |
July 19, 2007 |
Needle free hypodermic injector and ampule for intradermal,
subcutaneous and intramuscular injection
Abstract
A needle free hypodermic injector comprising a hand
manipulatable elongate housing, an impact impulse injection
mechanism within the housing, a suction generating means within the
housing and cooperable with the impact impulse injection mechanism,
a safety interlock mechanism, at least one medicament containing
ampule cooperable with the impact impulse injection mechanism and
the suction generating means and having a jet orifice through which
medicament is injectable through a skin surface in response to an
impulse placed on the medicament by the impact impulse injection
mechanism, and means to receive and hold the ampule on the injector
in registration with the impact impulse injection mechanism and in
communication with the suction generating means; whereby the
injector is adapted to expel the medicament from the ampule in a
jet stream of sufficient velocity to penetrate skin tissue held
against the orifice by the suction generating means and to deposit
the medicament intradermally, subcutaneously or intramuscularly
based on the position and angle of the jet orifice.
Inventors: |
Deslierres; John;
(Fullerton, CA) ; Anstead; Conrad; (San Juan
Capistrano, CA) ; Brant; Robert; (Satellite Beach,
FL) |
Correspondence
Address: |
SHERMAN & ASSOCIATES
415 NORTH ALFRED STREET
ALEXANDRIA
VA
22314
US
|
Family ID: |
34891108 |
Appl. No.: |
10/555742 |
Filed: |
May 10, 2004 |
PCT Filed: |
May 10, 2004 |
PCT NO: |
PCT/US04/14511 |
371 Date: |
August 22, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10603496 |
Jun 25, 2003 |
6939319 |
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10555742 |
Aug 22, 2006 |
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60469443 |
May 9, 2003 |
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60427708 |
Nov 20, 2002 |
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60469443 |
May 9, 2003 |
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Current U.S.
Class: |
604/68 |
Current CPC
Class: |
A61M 2005/2073 20130101;
A61M 5/30 20130101; A61M 2005/202 20130101; A61M 5/2053 20130101;
A61M 5/204 20130101 |
Class at
Publication: |
604/068 |
International
Class: |
A61M 5/30 20060101
A61M005/30 |
Claims
1. A needle free hypodermic injector comprising: a hand
manipulatable elongated housing, an impact impulse injection
mechanism within said housing, a suction generating means within
said housing and cooperable with said impact impulse injection
mechanism, a safety interlock mechanism, at least one medicament
containing ampule cooperable with said impact impulse injection
mechanism and said suction generating means and having at least one
jet orifice through which medicament is injectable through a skin
surface in response to an impulse placed on said medicament by said
impact impulse injection mechanism, and means to receive and hold
said ampule on said injector in registration with said impact
impulse injection mechanism and in communication with said suction
generating means, whereby said injector is adapted to expel said
medicament from said ampule in a jet stream of sufficient velocity
to penetrate skin tissue held against said orifice by said suction
generating means and to deposit said medicament intradermally,
subcutaneously or intramuscularly based on the position and angle
of said jet orifice and the force provided by said impact impulse
injection mechanism.
2. The needle free hypodermic injector of claim 1 wherein said
ampule comprises an elongated body having a forward end, a rearward
end, a substantially planar upper surface and a lower surface
having a downward offset between said forward end and said rearward
end, said offset providing a forward facing step face, a
horizontally disposed bore within said body extending from the
rearward end of said body to a point substantially adjacent to said
step face, said bore being open at said rearward end and having a
sealing plunger disposed therein, said bore further having at least
one jet orifice extending through said step face, whereby said bore
is capable of holding a quantity of medicament injectable through a
skin surface held against said orifice in response to said plunger
being driven forward in said bore by said impact impulse injection
mechanism.
3. The needle free hypodermic injector of claim 2 wherein said
ampule further comprises at least one suction port extending
vertically through said body from said upper surface to said lower
surface at a point forward of said step face, said suction port
being in fluid communication with said suction generating means
whereby a suction generated by said suction generating means is
applicable to said skin surface through said port whereby said skin
surface is drawn against said lower surface of said ampule and said
jet orifice prior to injection of said medicament.
4. The needle free hypodermic injector of claim 3 wherein said
impact impulse injection mechanism comprises: a drive rod linearly
reciprocatable within said housing between a cocked position and an
injection position and having a forward portion adapted to project
from said housing into said ampule bore to contact and drive said
plunger upon movement of said drive rod from said cocked position
to said injection position, a compressible drive spring
concentrically disposed along a rear portion of said drive rod
between a stationary abutment and a projection substantially midway
along said drive rod, a releasable latch mechanism adapted to
engage said projection and hold said drive rod in said cocked
position with said spring compressed, and a cocking mechanism
adapted to draw said drive rod rearward to said cocked position,
whereby actuating said cocking mechanism draws said drive rod
rearward in said housing compressing said drive spring between said
stationary abutment and said projection and positioning said drive
rod such that said latch mechanism engages said projection thereby
holding said drive rod in said cocked position ready for injection
and releasing said latch mechanism allows said spring to decompress
thereby driving said drive rod forward to engage said plunger in
said ampule and drive said plunger against said medicament whereby
said medicament is forced through said orifice and injected into
said skin surface.
5. The needle free hypodermic injector of claim 4 wherein said
suction generating means comprises a reciprocating piston disposed
in a cylinder in said housing, said piston being mechanically
connected to said cocking mechanism whereby said piston is moved in
said cylinder concurrently with cocking of said drive rod thereby
creating a suction behind said piston, and means providing fluid
communication between said cylinder and said ampule whereby said
suction is conveyed from said cylinder to said ampule suction
port.
6. The needle free hypodermic injector of claim 5 wherein said
safety interlock mechanism comprises a reciprocating rod responsive
to said suction and adapted to engage said latch mechanism in
response to incomplete suction applied through said ampule suction
port to said skin surface, whereby said latch mechanism is
prevented from operating to release said drive rod and drive spring
from said cocked position in the absence of secure contact of said
ampule with said skin surface.
7. The needle free hypodermic injector of claim 3 further
comprising a concave depression in said lower surface of said
ampule surrounding and concentric with said suction port, whereby a
suction generated by said suction generating means is applicable to
said skin surface through said port whereby said skin surface is
drawn against said lower surface of said ampule into said
depression and against said jet orifice prior to injection of said
medicament.
8. The needle free hypodermic injector of claim 7 wherein said jet
orifice is located in said step face adjacent to an upper edge
thereof and horizontally along a centerline of said bore whereby
said ampule is adapted for intradermal injection of medicament.
9. The needle free hypodermic injector of claim 7 wherein said jet
orifice is located in said step face at a downward angle relative
to a centerline of said bore whereby said ampule is adapted for
subcutaneous or intramuscular injection of medicament.
10. The needle free hypodermic injector of claim 2 wherein said
ampule further comprises two suction ports laterally spaced on
opposite sides of a center line of said ampule and extending
vertically through said body from said upper surface to said lower
surface at a point forward of said step face, said suction ports
being in fluid communication with said suction generating means,
said ampule further comprising a concave depression in said lower
surface encompassing the lower ends of said suction ports, whereby
a suction generated by said suction generating means is applicable
to said skin surface through said ports whereby said skin surface
is drawn against said lower surface of said ampule into said
depression and against said jet orifice prior to injection of said
medicament.
11. A needle free hypodermic injector comprising an injector
assembly and at least one medicament containing ampule removably
attachable to said injector assembly, said injector assembly
comprising an elongated hand manipulatable housing, said housing
comprising: a main body portion containing a mechanical impact
impulse means comprising a drive rod linearly reciprocatable within
said housing between a cocked position and an injection position, a
compressible drive spring linearly concentric about a rear portion
of said drive rod, said spring being confined between a stationary
abutment within said housing and a projection substantially midway
along said drive rod whereby rearward displacement of said drive
rod compresses said spring, a latch mechanism cooperating with said
projection to releasably hold said drive rod in a cocked position
wherein said spring is compressed, a release means to release said
latch mechanism when injection is desired, and a cocking means
cooperating with said drive rod and operable to draw said drive rod
in a rearward direction to said cocked position thereby compressing
said spring and engaging said latch mechanism; a forward nose
portion adapted to removably receive said at least one ampule and
having detent means to releasably secure said ampule to said
injector assembly when said impact impulse mechanism is in said
cocked position, said at least one ampule comprising a body having
a forward end and a rearward end, a substantially planar upper
surface and a stepped lower surface having a forward facing step
face therein, said body having formed therein behind said step face
a horizontally disposed substantially cylindrical medicament
chamber open at said rearward end and narrowing to at least one jet
orifice in said step face, said chamber being sized and positioned
to receive a forward end of said drive rod when said ampule is
secured to said injector assembly and said latch mechanism is
released, said chamber further containing a sealing plunger
providing a means to retain medicament in said chamber, said
plunger adapted to be engaged by said drive rod upon release of
said latch mechanism, whereby said drive rod drives said plunger
forward within said chamber forcing said medicament under pressure
through said jet orifice for injection into a skin surface held
against said ampule.
12. The needle free hypodermic injector of claim 11 further
comprising at least one suction port vertically disposed through
said ampule body forward of said jet orifice, a suction generating
means disposed in said main body portion of said housing and
suction conduits within said housing and said nose portion
providing fluid communication between said suction generating means
and said at least one suction port whereby suction generated by
said suction generating means is conveyed to said at least one
suction port of said ampule, said suction serving to draw said skin
surface against said ampule and said orifice prior to
injection.
13. The needle free hypodermic injector of claim 12 wherein said
suction generating means comprises a piston reciprocatable within a
cylinder in said housing, said piston being connected to and
operable by said cocking means to generate said suction.
14. The needle free hypodermic injector of claim 13 further
comprising a suction operated interlock adapted to lock said latch
mechanism against inadvertent operation in response to insufficient
suction applied to said skin surface, said interlock comprising a
piston operating within a cylinder adjacent to said suction
generating means and fluidly connected thereto by said suction
conduits, said piston having a locking rod projecting
longitudinally therefrom, said locking rod having an end remote
from said piston adapted to engage said latch mechanism when said
interlock is in said locked position and to disengage from said
latch mechanism when sufficient suction is applied to the skin
through said ampule thereby permitting release of said drive rod
and spring from said cocked position whereby said drive rod moves
forward to engage and drive said plunger within said ampule
chamber.
15. The needle free hypodermic injector of claim 14 wherein said
cocking means comprises a handle pivoted to said housing, a slide
frame within said housing mechanically connected to said handle so
as to reciprocate within said housing upon pivoting of said handle,
a drive rod latch attached to said slide frame and adapted to
engage said drive rod when said handle is pivoted away from said
housing and to draw said drive rod rearward against the force of
said compression drive spring when said handle is pivoted toward
said housing, said drive rod latch being biased to disengage from
said drive rod upon engagement of said latch mechanism, and a
mechanical link between said slide frame and said piston of said
suction generating means whereby said piston is moved within said
cylinder when said handle is pivoted and generates a suction at
said ampule when said handle is pivoted toward said housing.
16. The needle free hypodermic injector of claim 14 wherein said
cocking means comprises a pneumatically operated piston within said
housing, a source of compressed air, air conduits, a trigger
operated valve, a slide frame within said housing mechanically
connected to said pneumatically operated piston so as to
reciprocate within said housing upon actuation of said piston, a
drive rod latch attached to said slide frame and adapted to engage
said drive rod when said pneumatically operated piston is driven in
a first direction and to draw said drive rod rearward against the
force of said compression drive spring when said pneumatically
operated piston is driven in a second direction, said drive rod
latch being biased to disengage from said drive rod upon engagement
of said latch mechanism, and a mechanical link between said slide
frame and said piston of said suction generating means whereby said
suction piston is moved within said suction piston cylinder when
said pneumatically operated piston is actuated and generates a
suction at said ampule when said pneumatically operated piston is
driven in said second direction.
17. The needle free hypodermic injector of claim 13 further
comprising a concave depression in said lower surface of said
ampule surrounding and concentric with said suction port, whereby a
suction generated by said suction generating means is applicable to
said skin surface through said port whereby said skin surface is
drawn against said lower surface of said ampule into said
depression and against said jet orifice prior to injection of said
medicament.
18. The needle free hypodermic injector of claim 17 wherein said
jet orifice is located in said step face adjacent to an upper edge
thereof and horizontally along a centerline of said bore whereby
said ampule is adapted for intradermal injection of medicament.
19. The needle free hypodermic injector of claim 17 wherein said
jet orifice is located in said step face at a downward angle
relative to a centerline of said bore whereby said ampule is
adapted for subcutaneous or intramuscular injection of
medicament.
20. The needle free hypodermic injector of claim 11 wherein said
ampule further comprises two suction ports laterally spaced on
opposite sides of a center line of said ampule and extending
vertically through said body from said upper surface to said lower
surface at a point forward of said step face, said suction ports
being in fluid communication with said suction generating means,
said ampule further comprising a concave depression in said lower
surface encompassing the lower ends of said suction ports, whereby
a suction generated by said suction generating means is applicable
to said skin surface through said ports whereby said skin surface
is drawn against said lower surface of said ampule into said
depression and against said jet orifice prior to injection of said
medicament.
21. The needle free hypodermic injector of claim 14 wherein said at
least one ampule comprises a multiple ampule assembly comprising a
plurality of identical ampules arranged about and parallel to a
center shaft in a cylindrical assembly, said cylindrical assembly
being rotatable about said shaft for sequential registration of
each ampule in said assembly with said drive rod and said suction
conduits, said forward nose portion of said housing having a socket
into which said center shaft is received, said socket and said
shaft having cooperating detent means to removably secure said
multiple ampule assembly to said injector housing, and said nose
portion having detent means cooperable with said ampules to ensure
accurate regisration of each of said ampules in turn with said
drive rod and said suction conduits.
22. The needle free hypodermic injector of claim 14 wherein said at
least one ampule further comprises a filling port disposed in said
upper surface of said body, said filling port comprising a conduit
providing fluid communication with the forward end of said chamber
and a self sealing plug within said conduit adapted to receive a
needle or probe of a filling syringe for injecting medicament into
said chamber, said ampule further comprising a removable plug
temporarily closing said jet orifice during filling and removable
protective seals over said filing port, said removable plug and
said open rearward end of said chamber.
23. The needle free hypodermic injector of claim 14 wherein said
cocking means comprises an electrically actuated solenoid within
said housing, a source of electrical power, electrical circuits, a
trigger operated switch, a slide frame within said housing
mechanically connected to said solenoid so as to reciprocate within
said housing upon actuation of said solenoid, a drive rod latch
attached to said slide frame and adapted to engage said drive rod
when said solenoid is actuated in a first direction and to draw
said drive rod rearward against the force of said compression drive
spring when said solenoid is actuated in a second direction, said
drive rod latch being biased to disengage from said drive rod upon
engagement of said latch mechanism, and a mechanical link between
said slide frame and said piston of said suction generating means
whereby said suction piston is moved within said suction piston
cylinder when said solenoid is actuated and generates a suction at
said ampule when said pneumatically operated piston is driven in
said second direction.
24. The needle free hypodermic injector of claim 14 wherein said
drive rod is divided into two sections, a rear section with said
compression drive spring concentric thereabout and a forward
section adapted to enter said ampule, and a shock absorbing means
uniting said front and rear sections, whereby said shock absorbing
means operates to absorb the initial impact shock of release of
said drive spring whereby the impulse of said drive rod against
said ampule plunger is smooth and constant.
25. The needle free hypodermic injector of claim 4 wherein said
drive rod is divided into two sections, a rear section with said
compression drive spring concentric thereabout and a forward
section adapted to enter said ampule, and a shock absorbing means
uniting said front and rear sections, whereby said shock absorbing
means operates to absorb the initial impact shock of release of
said drive spring whereby the impulse of said drive rod against
said ampule plunger is smooth and constant.
26. The needle free hypodermic injector of claim 3 wherein said
impact impulse injection mechanism comprises: a drive rod linearly
reciprocatable within said housing between a cocked position and an
injection position and having a forward portion adapted to project
from said housing into said ampule bore to contact and drive said
plunger upon movement of said drive rod from said cocked position
to said injection position, a pneumatic means reciprocating said
drive rod between said cocked position and said injection position,
and a manually operated valve means actuating said pneumatic means,
whereby a first actuation of said pneumatic means draws said drive
rod rearward in said housing allowing attachment of an ampule to
said injector and a second actuation of said pneumatic means drives
said drive rod forward to engage said plunger in said ampule and
drive said plunger against said medicament whereby said medicament
is forced through said orifice and injected into said skin
surface.
27. The needle free hypodermic injector of claim 3 wherein said
impact impulse injection mechanism comprises: a drive rod linearly
reciprocatable within said housing between a cocked position and an
injection position and having a forward portion adapted to project
from said housing into said ampule bore to contact and drive said
plunger upon movement of said drive rod from said cocked position
to said injection position, a solenoid means reciprocating said
drive rod between said cocked position and said injection position,
and a manually operated switch means actuating said solenoid means,
whereby a first actuation of said solenoid means draws said drive
rod rearward in said housing allowing attachment of an ampule to
said injector and a second actuation of said solenoid means drives
said drive rod forward to engage said plunger in said ampule and
drive said plunger against said medicament whereby said medicament
is forced through said orifice and injected into said skin
surface.
28. The needle free hypodermic injector of claim 6 wherein said
cocking mechanism comprises a pneumatically actuated piston, a
slide frame within said housing mechanically connected to said
pneumatically actuated piston so as to reciprocate within said
housing upon pneumatic actuation of said pneumatically actuated
piston, valve means directing pneumatic fluid to said pneumatically
actuated piston, a drive rod latch attached to said slide frame and
adapted to engage said drive rod upon actuation of said piston,
said drive rod latch being biased to disengage from said drive rod
upon engagement of said releasable latch mechanism, and a
mechanical link between said pneumatically actuated piston and said
suction generating means whereby said suction generating means is
actuated when said pneumatically actuated piston is actuated.
29. The needle free hypodermic injector of claim 6 wherein said
cocking mechanism comprises an electrically actuated push-pull
solenoid having a reciprocating core, a slide frame within said
housing mechanically connected to said reciprocating core so as to
reciprocate within said housing upon actuation of said solenoid, an
electrical power source, switch means connecting said electrical
power source and said solenoid operable to actuate said solenoid, a
drive rod latch attached to said slide frame and adapted to engage
said drive rod upon actuation of said solenoid, said drive rod
latch being biased to disengage from said drive rod upon engagement
of said releasable latch mechanism, and a mechanical link between
said solenoid and said suction generating means whereby said
suction generating means is actuated when said solenoid is
actuated.
Description
FIELD OF THE INVENTION
[0001] This invention relates to a needle free, impact impulse
injector device and disposable, single use, fillable or pre-filled,
ampules therefor that are capable of delivering intradermal, (ID),
subcutaneous (SUB-Q) and intramuscular (IM) injections in human or
animal tissue by means of a thin high pressure liquid jet stream of
sufficient velocity to penetrate the tissue of the recipient. The
injector deposits medicament intradermally, or subcutaneously, or
intramuscularly, utilizing the single use, disposable, medicament
ampules that are designed to provide interfaces to the activation
device, allowing easy installation by hand or mechanically from a
multiple ampule dispensing apparatus, and providing exact
positioning and sealing to the activation device structure. The
ampules further contain features that induce a vacuum to stretch
the skin, keeping the skin precisely aligned with the jet orifice
for the short duration of the injection. The ampule's orifice has
different offset variations for ID, SUB-Q or IM injections. Ampules
and injectors may also be adjusted for variations in medicament
viscosity as required by various classes of medicaments including
providing multiple orifices in the ampule for injection of larger
doses or wider patterns. The injector device is manually,
pneumatically and/or electrically or electromagnetically activated
and provides interface features for mounting the ampules, and
features rendering it possible for the impulse force to inject the
medicament at any angle from horizontal to vertical relative to the
skin surface as well as at skew angles, as the activation process
is performed. In addition, the activation device provides safety
interlock features which prevent the impulse force from being
inadvertently activated, except when the ampule is properly
interfaced with the skin surface. The injector provides the
operator with a comfortable, light weight device that allows the
operator to quickly and easily load an ampule, properly position
the ampule on the skin surface, activate the impulse force, inject
the medicament and reset the activation device.
BACKGROUND OF THE INVENTION
[0002] In this invention, a needle-free ampule is provided which
discharges a pre-measured quantity of fluid medicament in a thin
jet at a sufficient velocity to penetrate the tissue of both humans
and animals to be treated or vaccinated at any angle from
horizontal to vertical. This invention utilizes a single-use,
disposable medicament ampule having the capability to apply a
vacuum to stretch and properly hold the skin prior to injecting a
medicament into the tissue, and a manually, pneumatically,
electrically or electromagnetically operated activation injector
device. The ampule and the injector are truly unique designs
constructed with materials presently being used in the medical
industry and designed to minimize effort, be easy to handle and
operate. The size and shape selected also minimize weight. The age,
size of hands, hand strength, skin type and thickness, as well as
visibility of operations, were very important considerations.
[0003] Present state of the art attempts to inject medications
intradermally have met with only limited success due to the
inherent difficulty associated with accurate positioning of the
skin relative to the injector jet opening and the lack of precise
control of the jet pressure vs. skin penetration when the injection
is performed normal to the skin surface. In addition, present
systems lack precise control and repeatability of the injection jet
velocity due to mechanical equipment tolerance variations within
the pressure/force generators utilized. Some present devices
present safety concerns due to the lack of safety interlocks to
prevent the device from being activated when not in proper contact
with the skin, and catastrophic failures have been observed in the
injector bodies in part caused by the lack of pressure control
inherent in the device designs.
[0004] Of particular interest is the ability to deliver medicament
to Langerhans cells within the skin. Langerhans cells are dendritic
cells generally located in the upper spinosum layer of the skin.
These cells are known to participate in cutaneous immune responses
and migrate from the skin to the lymph nodes. They possess surface
receptors common to macrophages and function as antigen presenting
cells to T and B lymphocytes. The Langerhans cells serve to fix and
process cutaneous antigens and, as such, are the first immune cells
to arrive at sites of inflammation. For this reason, Langerhans
cells are of particular interest in immune system studies with
respect to enhancing vaccine development and creating treatments
for auto-immune diseases and anti-rejection therapies.
[0005] Needleless injectors have been used as an alternative to
hypodermic needle type injectors for delivering drugs, vaccines,
local anaesthetics and other fluids into the human or animal
tissue. The medicament is discharged at high velocity so as to
first penetrate the epidermis and thereafter be deposited in the
tissues of the subject. An alternative method is to press the
discharge nozzle onto the skin and force the fluid at very high
pressure through the epidermis. Such prior art devices result in
substandard and painful injections because of this blasting action
and the inability to address the variables of flow control once the
skin is penetrated. They are also deficient with respect to being
able to provide the force necessary to penetrate the stratum
corneum while restricting medicament delivery to the intradermal
area generally and, specifically, the upper layers of the skin.
[0006] Prior art devices generally employ spring loaded piston
pumps to withdraw fluid from a reservoir. At the end of the piston
retracting stroke, the piston is disengaged from the retracting
mechanism and reverses direction to pressurize the fluid for
ejection from the delivery nozzle. In some devices the fluid is
contained in an adjacent container or vessel within the device and
the fluid is fed into the nozzle under pressure and discharged
under pressure through the delivery nozzle. In other prior art
devices the piston is driven on the discharge stroke by gas or an
electric motor instead of a spring. In most of these devices the
discharge orifice must be placed firmly on the skin to make direct
contact of the nozzle with the epidermis. To achieve suitable
contact, the orifice is pressed firmly into the epidermis by the
operator at an angle that is normal to the skin surface, usually
perpendicular to the plane of the skin, so as to stretch the
epidermis at the point of contact and thereby increase the ability
of the injection to penetrate the stretched tissue at the point of
contact. However, the pressing of the orifice into the epidermis is
a variable that is dependent on the device's operator and the
ability of the recipients to tolerate the device being pressed
against their anatomy.
[0007] Typically, the use of existing devices results in loss of
medicament at the nozzle entry point, poor injections on account of
the recipient's movements or the operator's inexperience and
receipt of the injection at an angle that either does not penetrate
or penetrates too much for placement and dispersal of the
medicament at the correct depth and layer of tissue. In addition,
premature operations are common, as well as relative movement
between the epidermis and orifice which can cause tearing of the
skin during injection, resulting in pain and poor transfer of the
medicament to the recipient. In other instances, the epidermis will
deform away from the orifice and the injection fluid will leak away
from the point of entry. At other times, the devices attempt to
stretch the epidermis by deforming over the discharge orifice. In
all of these conditions, the success of the injection procedure
depends and rests on the ability of the operator to consistently
perform, using the device to get an acceptable discharge and
penetration of the epidermis.
[0008] Various methods have been proposed to overcome these
problems such as powered injectors, sensing and control devices to
enhance their performance, including compressed gas cylinder and
electrical injectors, which are often heavy and unwieldy and
encumbered with variations in gas supply, pressure, leakage.
[0009] The need for medicament supply and personnel skill have
produced problems for using these devices, for example, precisely
measuring and controlling of the quantity of medicament
administered and ensuring that the injector delivers the correct
amount of medicament into the proper tissue. The following patents
have attempted to address these known problems, with varying
degrees of success, and proposed some methods as follows:
[0010] U.S. Pat. No. 3,859,996, Mizzy, discloses a controlled leak
method to ensure that the injector orifice is placed correctly at
the required pressure on the subject's skin and at the correct
attitude to the skin. When placement conditions are met, controlled
leak is sealed off by contact pressure on the subject's skin and
the pressure within the injector control circuit rises until a
pressure sensitive pilot valve opens to admit high pressure gas to
drive the piston and inject the medicament. This use of valving and
pressure gas renders the device complex to manufacture and use and
does not apply to the present invention.
[0011] WO Patent 82/02835, Cohen and Ep-A-347190, Finger, disclose
a method to improve the seal between the orifice and the skin and
prevent relative movement between each. This method is to employ a
vacuum device to suck the epidermis directly and firmly onto the
discharge orifice. The discharge orifice is positioned normal to
the skin surface in order to suck the epidermis into the orifice.
This method for injection of the medicament into the skin and the
injector mechanism are different and do not apply to the present
invention because of its unique ampule design.
[0012] U.S. Pat. No. 3,859,996, Mizzy, further discloses a pressure
sensitive sleeve on the injector which is placed on the subject and
whereby operation of the injector is prevented from operating until
the correct contact pressure between orifice and the skin is
achieved. The basic aim is to stretch the epidermis over the
discharge orifice and apply the pressurized medicament at a rate
which is higher than the rate at which the epidermis will deform
away from the orifice. This method of stretching the skin on to the
orifice, together with the arrangements of the mechanism are
totally different from the present invention and, consequently, do
not apply.
[0013] U.S. Pat. No. 5,480,381, T. Weston, discloses a means of
pressuring the medicament at a sufficiently high rate to pierce the
epidermis before it has time to deform away from the orifice. In
addition, the device directly senses that the pressure of the
discharge orifice on the subject's epidermis is at a predetermined
value to permit operation of the injector. The device is based on a
cam and cam follower mechanism for mechanical sequencing, and
contains a chamber provided with a liquid outlet for expelling the
liquid, and an impact member, to dispell the liquid. The sequencing
and cam operation are driven by an electric motor gear-box, and
along with the cam action sequencing and adjustable pressure
sensing do not apply to the present invention.
[0014] U.S. Pat. No. 5,891,086, T. Weston, describes a needleless
injector that contains a chamber that is pre-filled with a
pressurized gas which exerts a constant force on an impact member
in order to strike components of a cartridge and expell a dose of
medicament. This device contains an adjustment knob which sets the
dose and the impact gap, and uses direct contact pressure sensing
to initiate the injection. This use of contact pressure sensing,
the need for constant adjustment and the use of pressurized gas to
implement the injection process do not apply to the present
invention.
BRIEF SUMMARY OF THE INVENTION
[0015] The subject of the present invention represents an
innovative approach to hypodermic needle-free injections, either
Intradermal (ID), Subcutaneous (SUB-Q) or Intramuscular (IM),
providing a process and a mechanization which contains disposable
filled or prefilled medicament ampules and a manuallyor
automatically operated activation device. There are many advantages
covered by this invention. Above all, the injection uses horizontal
impact impulse jet pressure, and thus it spreads the particles over
a larger area than using a needle syringe, decreases the local
pressure in the tissue, and eliminates leakage of the fluid from
the opening in the tissue thereby reducing the possibility of
spreading infections. The apparatus is capable of injection at any
angle between horizontal and vertical in addition to laterally
relative to the center line of the ampule, depending on the
specific conditions of the medicament, injection site, etc. A
unique feature of this invention is that the medicament is driven
out of the ampule that holds it with a known and controlled impact
impulse force.
[0016] A further innovation of the present invention is the process
of the stretching of the skin, which increases permeability thus
reducing the amount of energy required to inject fluid into a
tissue, in conjunction with the injecting of the fluid horizontally
to vertically and/or laterally into the skin which allows
controlled positioning of the tissue for intradermal, subcutaneous
or intramuscular injections. Also significant is the introduction
of a safety feature built into the injector that will not allow
operation until the skin is properly positioned.
[0017] The ampule interfaces with the injector allowing
installation by hand or mechanical means, and has features for the
application a vacuum produced by the operation of the injector that
stretches and properly holds the skin, precisely aligned with the
jet orifice during the short duration of the injection. The
activation device provides the interface for mounting the ampule
and for delivering the impact impulse force required to inject the
medicament as the activation process is performed. Each ampule body
includes a see through window with external gradient markers to
indicate the quantity of medicament the ampule contains.
[0018] In a second embodiment of this invention, the injector
operates in like manner as the primary embodiment, with the
exception that certain functions and sequence operating components
utilize external air pressure for activation. The handle has been
replaced with a finger operated trigger, and return functions are
all air driven. Alternatively, the pneumatic operation can be
achieved using an electronic solenoid with power provided by a
battery pack that may be part of or separate from the injector. The
ampule configuration in both embodiments is identical and its
attachment to the injector and filling procedure are the same.
Inasmuch as each injector embodiment utilizes the same ampule, then
each provides a means for administering either Intradermal (ID),
Subcutaneous (SUB-Q) or Intramuscular (IM) injections.
[0019] A still further embodiment of the present invention provides
an injector that is adapted to receive a multiple ampule assembly
and a multiple ampule assembly therefor. The components and
operation of the injector are substantially identical to those of
the other embodiments except that the front end of the injector is
modified to receive a rotatable, multiple ampule assembly, which
assembly has a plurality of ampules arranged in a cylindrical
cartridge. The cartridge is rotatable on the forward end of the
injector so as to bring each ampule thereof into registration with
the suction and injection means of the injector.
[0020] Present state of the art attempts to inject medications
intradermally have met with only limited success due to the
inherent difficulty associated with accurate positioning of the
skin relative to the injector jet opening and the lack of precise
control of the jet pressure versus skin penetration when the
injection is performed normal to the skin surface. In addition,
present systems lack precise control and repeatability of the
injection jet velocity due to mechanical equipment tolerance
variations within the pressure/force generators utilized. Some
present devices indicate safety concerns due to the lack of safety
interlocks to prevent the device from being accidentally activated
when not in proper contact with the skin, and observed catastrophic
failures in the injector bodies in part caused by the lack of
precise pressure control inherent in the device designs.
[0021] The present invention overcomes these deficiencies by the
combination of the injector device and the ampule used therewith.
The ampule is a key element of the system as it is the part which
holds the medicament to be injected and interfaces with both the
injector and the patient's skin surface to apply the suction
generated by the injector in order to draw the skin tight for
proper injection. The ampule further interfaces with the injector
to provide proper functioning of the safety interlock since release
of the interlock requires establishing a full suction on the system
which cannot be achieved without the ampule. With the ampule and
the injector combination of the present invention it is now
possible to achieve needle-less injection of medicament
intradermally, subcutaneously and intramuscularly at any angle
relative to the skin surface. Furthermore, the ampule and injector
combination of the present invention are capable of achieving the
shallow intradermal injection necessary to accurately and reliably
deliver medicament to the Langerhans cells in the upper spinosum
layer of the skin.
[0022] Thus, the present invention provides a needle free
hypodermic injector comprising a hand manipulatable elongate
housing, an impact impulse injection mechanism within the housing,
a suction generating means within the housing and cooperable with
the impact impulse injection mechanism, a safety interlock
mechanism, at least one medicament containing ampule cooperable
with the impact impulse injection mechanism and the suction
generating means and having a jet orifice through which medicament
is injectable through a skin surface in response to an impulse
placed on the medicament by the impact impulse injection mechanism,
and means to receive and hold the ampule on the injector in
registration with the impact impulse injection mechanism and in
communication with the suction generating means; whereby the
injector is adapted to expel the medicament from the ampule in a
jet stream of sufficient velocity to penetrate skin tissue held
against the orifice by the suction generating means and to deposit
the medicament intradermally, subcutaneously or intramuscularly
based on the position and angle of the jet orifice.
[0023] The present invention further provides an ampule for a
needle free hypodermic injector, wherein the ampule comprises an
elongated body having a forward end, a rearward end, a
substantially planar upper surface and a lower surface having a
downward offset between the forward end and the rearward end, this
offset providing a forward facing step face, a horizontally
disposed bore within the body extending from the rearward end of
the body to a point substantially adjacent to the step face, the
bore being open at the rearward end and having a sealing plunger
disposed therein to be driven by the impact impulse mechanism, the
bore further having a jet orifice extending through the step face,
whereby the bore is capable of holding a quantity of medicament
injectable through a skin surface held against the orifice in
response to the plunger being driven forward in the bore by the
impact impulse injection mechanism.
[0024] The present invention still further provides a needle free
hypodermic injector wherein the ampule further comprises at least
one suction port extending vertically through the body from the
upper surface to the lower surface at a point forward of the step
face, the suction port being in fluid communication with the
suction generating means whereby a suction generated by the suction
generating means is applicable to the skin surface through the port
to draw the skin surface upward against the lower surface of the
ampule and the jet orifice prior to injection thereby stretching
the skin to improve its porosity to the jet of medicament and,
depending on the angle and placement of the orifice, to direct the
jet of medicament intradermally, subcutaneously or
intramuscularly.
[0025] The present invention still further provides a needle free
hypodermic injector comprising an injector assembly and at least
one medicament containing ampule removably attachable to the
injector assembly, the injector assembly comprising an elongated
hand manipulatable housing, the housing comprising a main body
portion containing a mechanical impact impulse means comprising a
drive rod linearly reciprocatable within the housing between a
cocked position and an injection position, a compressible drive
spring linearly concentric about a rear portion of the drive rod,
the spring being confined between a stationary abutment within the
housing and a projection substantially midway along the drive rod
whereby rearward displacement of the drive rod compresses the
spring, a latch mechanism cooperating with the projection to
releasably hold the drive rod in a cocked position wherein the
spring is compressed, a release means to release the latch
mechanism when injection is desired, and a cocking means
cooperating with the drive rod and operable to draw the drive rod
in a rearward direction to the cocked position thereby compressing
the spring and engaging the latch mechanism. The injector further
comprises a forward nose portion adapted to removably receive at
least one ampule and having detent means to releasably secure the
ampule to the injector assembly when the impact impulse mechanism
is in the cocked position, the at least one ampule comprising a
body having a forward end and a rearward end, a substantially
planar upper surface and a stepped lower surface having a forward
facing step face therein, the body having formed therein behind the
step face a horizontally disposed substantially cylindrical
medicament chamber open at the rearward end and narrowing to a jet
orifice in the step face, the chamber being sized and positioned to
receive a forward end of the drive rod when the ampule is secured
to the injector assembly and the latch mechanism is released, the
chamber further containing a sealing plunger providing a means to
retain medicament in the chamber, the plunger adapted to be engaged
by the drive rod upon release of the latch mechanism, whereby the
drive rod drives the plunger forward within the horizontally
disposed chamber forcing the medicament under pressure through the
jet orifice for injection into a skin surface held against the
ampule.
[0026] The needle free hypodermic injector of the present invention
further comprises at least one suction port vertically disposed
through the ampule body forward of the jet orifice, a suction
generating means disposed in the main body portion of the housing
and suction conduits within the housing and the nose portion
providing fluid communication between the suction generating means
and the at least one suction port whereby suction generated by the
suction generating means is conveyed to the at least one suction
port of the ampule, the suction serving to draw the skin surface
against the ampule and the orifice prior to injection. To improve
the suction of the skin surface against the ampule and, preferably
in the case of intradermal injection, to lift the skin surface
slightly higher than the level of the jet orifice thereby providing
an injection path to the spinosum layer of the skin, it is
preferred that the lower surface of the ampule immediately
surrounding the suction port be concave thereby forming a slight
depression into which the skin is drawn by the suction.
[0027] Although the injector does not touch the skin tissue around
the injection, it can be submerged in alcohol for sterilization, if
desired, since all materials are presently being used in the
medical industry, and are compatible with all current sterilization
methods.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0028] FIG. 1 is a top view of the needle-free injector of the
present invention.
[0029] FIG. 2 is a side view of the needle-free injector in a
manual configuration.
[0030] FIG. 3 is a longitudinal cross section of the needle-free
injector of FIG. 2 prior to injection.
[0031] FIG. 4 is a cross section of the needle-free injector of
FIG. 2 after injection.
[0032] FIG. 5 is a view of the end cap of the needle-free injector
of FIG. 2.
[0033] FIG. 6 is a vertical cross section through the injector of
FIG. 2 at the vacuum piston.
[0034] FIG. 7 is a partial longitudinal cross section of the
injector of FIG. 2 through the suction manifold.
[0035] FIG. 8 is a longitudinal cross section of an alternative
embodiment of the injector configured for operation by air pressure
prior to injection.
[0036] FIG. 9 is a longitudinal cross section of the alternative
embodiment of the injector configured for operation by air pressure
after injection.
[0037] FIG. 10A is a side view of the return piston housing of the
alternative embodiment of the injector of FIG. 8.
[0038] FIG. 10B is an end view of the return piston housing of the
alternative embodiment of the injector of FIG. 8.
[0039] FIG. 11 is a side view of an ampule according to the present
invention.
[0040] FIG. 12 is a top view of an ampule according to the present
invention.
[0041] FIG. 13 is a longitudinal cross section through the ampule
of FIG. 11.
[0042] FIG. 14 is a view of an ampule in an adaptor for filing.
[0043] FIG. 15 is a top view of an alternative embodiment of an
ampule according to the present invention having a stopper for
filing via a hypodermic syringe.
[0044] FIG. 16 is a longitudinal cross section of the ampule of
FIG. 15 with protective coverings in place.
[0045] FIG. 17 is a longitudinal cross section of the ampule of
FIG. 15 being filled.
[0046] FIG. 18 is a longitudinal cross section of the ampule of
FIG. 15 filled with medicament and sealed for use.
[0047] FIG. 19 is a side view of a multiple ampule unit
injector.
[0048] FIG. 20 is a longitudinal cross section of the multiple
ampule unit injector of FIG. 19.
[0049] FIG. 21 is a detailed cross section of the forward end of
the multiple ampule unit injector of FIG. 19.
[0050] FIG. 22 is a vertical cross section of the multiple ampule
unit injector of FIG. 19 through the vacuum ports of the ampule
assembly.
[0051] FIG. 23 is a view of the ampule assembly showing adjacent
ampules.
[0052] FIG. 24 is a view showing an intradermal injection ampule in
use.
[0053] FIG. 25 is a close-up view of the intradermal injection.
[0054] FIG. 26 is a view showing a subcutaneous injection ampule in
use.
[0055] FIG. 27 is a close-up view of the subcutaneous
injection.
LIST OF PARTS AND IDENTIFICATION NUMBERS
[0056] 20--Injector Assembly (complete) [0057] 21--Housing [0058]
22--Retainer Clamp [0059] 23--Release Button [0060] 24--Pivot
(Handle) [0061] 25--Ampule [0062] 26--Detent [0063] 27--Access
Panel [0064] 28--End Cap [0065] 29--Hand Grips [0066] 30--Handle
[0067] 31--Medicament [0068] 32--Snap Ring [0069] 33--Torsion
Spring [0070] 34--Seal (Large Piston) [0071] 35--Vacuum Piston
[0072] 36--Interlock Piston Rod [0073] 37--O-Ring [0074]
38--Suction Port A [0075] 39--Retainer Ring (Small Piston) [0076]
40--Extension Link [0077] 41--Pivot (Link) [0078] 42--Drive Spring
[0079] 43--Drive Rod [0080] 44--Release Catch [0081] 45--Slide
Frame [0082] 46--Extension (Piston) [0083] 47--Connector Link
[0084] 48--Drive Rod Latch [0085] 49--External Air Source Fitting
[0086] 50--Ramp [0087] 51--Roll Pins [0088] 52--Pivot (Rod Latch)
[0089] 53--Torsion Spring (Rod Latch) [0090] 54--Pin [0091]
55--Release Arm [0092] 56--Shaft [0093] 57--Pivot (Release) [0094]
58--Pin (Latch) [0095] 59--Retention Ring [0096] 60--Pivot (Slide)
[0097] 61--Locking Tabs [0098] 62--Cylinder Bore (with dosage
markers) [0099] 63--Suction Ports [0100] 64--Skin [0101] 65--Ampule
Plunger [0102] 66--Outlet Orifice [0103] 67--Ampule Body [0104]
68--Contour [0105] 69--Vacuum Port Plane [0106] 70--Vacuum Port
Seal [0107] 71--Suction Tube [0108] 72--Suction Manifold [0109]
73--Suction Passage [0110] 74--Insert Fairing [0111] 75--Cushion
Washer [0112] 76--Screw [0113] 77--Compression Spring [0114]
78--Drive Cylinder [0115] 79--Tooth Release Catch [0116]
80--Interlock Hole [0117] 81--O-Ring [0118] 82--Connecting Rod
[0119] 83--Return Piston [0120] 84--O-Ring [0121] 85--Compression
Spring [0122] 86--Retention Screws [0123] 87--Actuation Frame
[0124] 88--Pin [0125] 89--Trigger Assembly [0126] 90--Push Rod
[0127] 91--Pressure Ports [0128] 92--O-Ring [0129] 93--Plug [0130]
94--Spring Retention Cap [0131] 95--Support Fitting [0132]
96--O-Ring [0133] 97--Pressure Bleed [0134] 98--Spring Retention
Plug [0135] 99--Compression Spring [0136] 100--Valve [0137]
101--O-Ring [0138] 102--Extension Housing [0139] 103--Luer Adaptor
[0140] 104--Rubber Seal [0141] 105--Bushing [0142] 106--Stopper
[0143] 107--Pull-off Protection Shield (upper) [0144] 108--Pull-off
Protection Shield (lower) [0145] 109--Syringe [0146] 110--Nozzle
[0147] 111--Probe [0148] 112--Retraction Handle [0149] 113--Vacuum
Space [0150] 114--Flat Surface [0151] 115--Passage [0152]
116--Shoulder Stop [0153] 117--CapturePad [0154] 118--Ampule
Orifice Plug [0155] 119--Enlarged Head [0156] 120--Projecting Ring
[0157] 121--Protective Outer Doubler [0158] 122--Slide Frame Groove
[0159] 123--Cylinder [0160] 124--Annular Abutment Surface [0161]
125--Channel [0162] 126--Small Piston [0163] 127--Small Cylinder
[0164] 128--Drive Spring Chamber [0165] 129--Vacuum Ports [0166]
130--Valve Cavity [0167] 131--Undercut [0168] 132--AirPassage
[0169] 133--Return Piston Pocket [0170] 134--Retention Cap Pocket
[0171] 135--Port [0172] 136--Ampule Nose Portion [0173] 137--Ampule
Bore Chamber Portion [0174] 138--Offset [0175] 139--Pocket [0176]
140--Depression (Well) [0177] 141--Dosage Markers [0178] 142--Luer
Connection [0179] 143--Filling Port [0180] 200--Multiple Ampule
Assembly [0181] 201--Housing [0182] 202--Multiple Unit Cylinder
[0183] 203--Vacuum Ports [0184] 204--Detent Pockets [0185]
205--Multiple Unit Cartridge [0186] 206--Shaft [0187] 207--Position
Detent [0188] 208--Rotation Knob [0189] 209--Sleeve [0190]
210--Multiple Unit Suction Tube [0191] 211--SuctionTubeSeal [0192]
212--Multiple Unit Ampule Plunger [0193] 213--Annular Groove [0194]
214--Detent [0195] 215--Ball [0196] 216--Spring [0197] 217--Detent
[0198] 218--Shaft Receiving Hole [0199] 219--Electronic
Identification Code [0200] 220--Removable Tab [0201] 221--Window
[0202] 222--Sequential Number [0203] 223--Capture Pin
DETAILED DESCRIPTION OF THE INVENTION
[0204] This invention relates to a device and method for a
needle-less jet injection of a medicament into the skin of a human
or animal from a disposable tillable or pre-filled ampule that uses
a vacuum to stretch the recipient's skin in order to increase its
permeability for injection and which, in turn, reduces the amount
of energy required to inject the medicament into the skin tissue.
The vacuum further positions the skin correctly for injection of
the medicament.
[0205] The method uses the device to inject a premeasured dose of
medicament by means of a high pressure jet stream of sufficient
velocity to penetrate human or animal epidermis, depositing the
medicament intradermally, or subcutaneously, or intramuscularly,
depending on the offset and angle of the disposable ampule's
orifice to the epidermis and the impact impulse force. Another
novelty of the process consists in injecting the medicament
horizontally, or any other desired angle, into the skin from a
single use ampule, spreading the particles over a larger area than
when using a needle syringe.
[0206] The method provides decreased local pressure in the skin
tissue at the point of injection, thus reducing local pain,
minimizing tissue damage, eliminating leakage of fluid at the
injection opening, and reducing the possibility of spreading
infections, while providing a safety device to prevent inadvertent
triggering of the injector.
[0207] The injector assembly 20 shown in FIG. 1 comprises a molded
housing 21 containing the injector mechanism that is activated by a
release button 23. Activation of the injector 20 disperses the
medicament 31 contained in ampule 25 shown in FIG. 2. The ampule 25
is retained on the injector 21 by a retainer clamp 22 attached to
the forward end of the injector 20 and by an insert fairing 74 on
the underside of the injector 20 at the opposite end of the ampule
25. The principal embodiment of the injector 20 is manually
operated and is cocked for release of the medicament by rotation of
a handle 30, around a shaft 56. The handle 30 is provided with
shaped hand grips 29 for ease of operation. The handle 30 rotates
at handle pivot 24.
[0208] The injector housing 21 is provided with an access panel 27
and an end cap 28 for ease of assembly and service of the mechanism
within the housing 21. FIG. 3 shows a cross section view of the
injector 20 prior to activation of the mechanism for injection. The
mechanism within the housing 21 comprises a piston 35 adapted to
create a vacuum for stretching the recipient's skin at the
injection site immediately prior to injection and a release
mechanism to pressure drive the medicament into the skin tissue.
The mechanism within the housing 21 of the injector 20 also
comprises a compression drive spring 42 which provides the force
that drives one end of a drive rod 43 into the ampule 25 that
contains the medicament. The drive rod 43 has a retention ring 59
at the opposite end which cooperates with a means for locking the
drive rod 43 with the compression drive spring 42 compressed. A
projecting ring 120 substantially midway along drive rod 43
provides a surface on the drive rod 43 for the compression spring
42 to push against. The opposite end of the compression drive
spring 42 abuts against an annular surface 123 at the end of drive
spring chamber 128 within housing 21. To eject the medicament 31
from the ampule 25, the mechanism of the injector 20 is cocked by
rotation of the handle 30 to the position of FIG. 4, which pulls
slide frame 45, via extension link 40, forward so that drive rod
latch 48 snares retention ring 59 on the end of drive spring drive
rod 43. As the slide frame 45 is pulled forward by the link 40
attached to the handle 30, the upper surface of latch 48 slides
along spring ramp 50 and is rotated downward to engage the forward
surface of retention ring 59. The drive rod latch 48 is preloaded
to a release position by a torsion spring 53 at the pivot point of
latch 48 and side frame 45. Contact of latch 48 with spring ramp 50
pushes latch 48 downward against the torsion spring load to the
locking position that captures the drive rod retention ring 59.
Spring ramp 50 is preferably retained in the housing 21 by two pins
51. The drive rod latch 48 is supported by the slide frame 45 and
pivots around a pin joint 52 in the upright supports of the slide
frame 45 and is retained in the slide frame with a horizontal pin
58 that also retains a connector link 47. The slide frame 45 has a
horizontal lower leg that slides in and is guided by a machined-in
groove 122 in the housing 21. The horizontal lower leg of side
frame 45 is provided with an end termination pivot point 60 for
pivoting attachment of extension link 40. The rotation of the
handle 30 back to the starting position shown in FIG. 3 pushes the
drive rod 45 rearward and compresses the spring 42 between annular
surface 123 and projecting ring 120. When handle 30 is fully
rotated back to the starting position, spring 42 is fully
compressed and projecting ring 120 is engaged by tooth release
catch 79 which depends from the underside of release catch 44 and
holds spring 42 and drive rod 43 in a compressed position ready for
release to drive the medicament 31 out of the ampule 25 with the
drive rod 43. To achieve this movement of the slide frame 45 with
the link 40 that is attached to both slide frame 45 and handle 30,
the link 40 rotates around pivot 41 on the handle and pivot 60 on
the slide frame.
[0209] The handle 30 itself is attached to the injector assembly
housing 21 and rotates around the pivot 24. The injector handle 30
attached to the outside of the housing 21 comprises two contoured
legs that straddle the housing 21 with and each leg being attached
to the pivot point 24 on either side of the housing structure by
capture pin 58. The free end of injector handle 31 is formed or
molded to provide finger or hand grip 29. The handle 30 is of
extended length in order to provide sufficient leverage for
compressing the drive rod compression spring 42. Extension link 40
can rotate around its handle attachment point 41 permitting the
extension link 40 to rotate when the handle 30 is also rotated. A
similar pivot connection to the slide frame 45 at pin joint 60
permits extension link 40 to pivot relative to slide frame 45 so
that when the handle 30 is rotated down or up the extension link 40
pushes or pulls on the slide frame 45.
[0210] In addition to pulling drive rod 43 against compression
spring 42, the slide frame 45 has a second function. To ensure good
contact of the ampule 25 with the skin of the recipient, during the
medicament injection, the injector 20 creates a vacuum at this
contact point of the ampule 25 and the recipient's skin. To achieve
this vacuum, the slide frame 45 has attached to it a second
connector link 47 extending rearward from latch 48 to engage vacuum
piston 35 in the rear of housing 21. The slide frame 45 movement in
the rearward direction compresses the compression spring 42 and
pulls the drive rod 43 to the cocked position. Simultaneously,
connector link 47 which is attached to the upright supports of the
slide frame 45 at one end and pin joint 51 by capture pin 58 at the
opposite end is attached to piston extension 46 by rod latch pivot
pin 54, pulls piston 35 rearward within cylinder 123 which is
milled in the rear of housing 21. The piston 35 provides the vacuum
for the injector 20, when applied to the recipient's skin, to pull
and stretch the skin tight against the suction ports 63, in the
ampule 25, which serves to position the outlet orifice 66 correctly
for injection of the medicament. In addition, the vacuum system
includes a safety device to prevent inadvertent triggering of the
injector 20 without first obtaining a good vacuum seal of the
ampule 25 to the skin. The safety device comprises a small
interlock piston rod 36, which is adapted to engage and disengage a
release catch 44 in response to a vacuum generated by piston 35.
Interlock piston rod 36 reciprocates within channel 125 and is
provided with a small piston 126 on its rearward end which is
located within a small cylinder 127 communicating with the cylinder
123 of vacuum piston 35. The piston 35 has an O-ring seal 34 that
ensures that the piston can produce a vacuum within cylinder 123
for actuation of the small interlock piston rod 36. The vacuum
provided acts on small piston 126 to position the small interlock
piston rod 36 to engage or disengage the release arm 55, thereby
locking it in a non-release, or unlocking it in a release position.
The release arm 55 is able to rotate between the two operating
positions around a pivot pin 54 that interfaces with the injector
housing structure 21 and is biased to the lock position by torsion
spring 33 on pivot pin 54.
[0211] A pair of connector links 47 straddle the vacuum piston 35
and are connected to it by piston extension 46. Movement of the
slide frame 45 drives the vacuum piston 35, and the vacuum created
is ported to the ampule 25 through a suction tube 71. To release
the drive rod 43, the injector is provided with a release button 23
which, when pressed, rotates the release arm 55 about pivot pin 54.
As the release arm 55 engages release catch 44, rotation of release
arm 55 downward causes release catch 44 to pivot upward, releasing
drive rod 43 which is then forced forward by drive spring 42 so
that the forward end of drive rod 43 enters ampule 25. Release
catch 44 rotates around latch pin 58 against torsion spring 53. The
release button 23 is installed in the injector housing 21 structure
so that when pushed inward it contacts the release arm 55 acting as
a cam and causing the release arm 55 to rotate downward and, in
turn, lift the release catch 43, that locks the compression spring
42 in its loaded compression position. The release button 23 is
retained in the injector housing 21 flush with the housing's outer
surface to prevent inadvertent actuation until required by the
operating procedure, and is retained in the housing structure with
a retention snap ring 32. As noted, release catch 44 includes
torsion spring 53 which is tensioned to hold release catch 44 in
the lock position to hold the drive rod 43 against the compressed
compression spring 42. An angular end surface of release catch 44
provides a means for contact with a corresponding angular end
surface of the release arm 55 so that, during the release function,
the release catch 44 is pivoted upward around the pivot point
provided by the latch pin 58 that engages the housing 21 structure
as release arm 55 is pushed downward by button 23.
[0212] FIG. 4 shows a cross section view of the injector 20 after
injection of the medicament and with the handle 30 rotated away
from the housing. To ensure that the drive rod latch 48 always
engages, the drive rod retention ring 59, a spring ramp 50 forces
the drive rod latch down to engage and lock on to the projecting
retention ring 59. The spring ramp is retained by two roll pins 51.
To ensure that the drive rod latch 48 releases at the end of the
slide frame 45 travel, the latch 48 has a torsion spring 53 that is
retained by the pin 58, and drives the latch to the release
position around pivot pin 52. To achieve the vacuum, piston 35 has
an annular O-ring seal 34 contained within an annular groove in the
surface of piston 35 and which engages the wall of cylinder 123.
The vacuum generated by piston 35 is conveyed to the ampule 25 by
suction passages 73 and vacuum tube 71 which is provided with a
seal 70 at the point of interface with the ampule 25 to ensure the
function of suction of the skin at ampule contact for efficient
injection of the medicament by the injector. When pressed, the
injection release button's 23 lower surface cams down the release
arm 55 and forces the release catch 44 upward. The release arm 55
rotates around pivot point 57 that holds the pin 54 and torsion
spring 33.
[0213] To ensure that the release arm cannot accidently be rotated
by someone pressing on the button 23 before it is needed and to
ensure that the recipient's skin is in contact with the ampule 25
ready for injection, the injector 20 contains a locking feature
that prevents the possible release of the drive rod 43. When the
handle 30 is rotated, movement of the vacuum piston 35 within
cylinder 123 creates pressure or vacuum against small piston 126
resulting in reciprocation of interlock piston rod 36 between the
locked and unlocked positions. Pressure generated within cylinder
123 by piston 35 as handle 30 is rotated downward to engage drive
rod latch 48 with retention ring 59, pushes interlock piston rod 36
forward into the locked position with release arm 55.
Alternatively, rotation of handle 30 upward moves piston 35
rearward within cylinder 123 generating a vacuum which, when ampule
25 is against the skin, is sufficient to act against small piston
126 to draw interlock piston rod 26 rearward, thereby unlocking
release arm 55. Until there is full suction on the system, the
interlock piston rod 36 is interlocked with the release arm 55 by
engagement of the end of rod 36 with mating interlock hole 80 in
release arm 55. In this configuration, release arm 55 is incapable
of rotation when button 23 is pressed, release catch 44 cannot be
pivoted out of engagement with projecting ring 120 which prevents
spring 42 from forcing drive rod 43 forward into ampule 25 and no
medicament can be ejected. The small piston 126 on interlock piston
rod 36 is provided with an O-ring 37 to maintain the vacuum between
large piston 35 and the interlock piston rod 36. In the space
between the two sealed pistons there is a suction port A 38, shown
in FIG. 7, for the transfer of vaccum from cylinder 123 to the
ampule 25. To prevent the interlock piston rod 36 from
overtraveling, and to hold it in its correct position for
activation by the vacuum, the interlock piston rod 36 is retained
with a retainer ring 39 in small cylinder 127. To ensure that the
large drive compression spring 42 does not drive the drive rod 43
hard against an end stop and does not damage the ampule 25, the
drive rod 43 bottoms out on a cushion washer 75 at the end of drive
spring chamber 128, when released. FIG. 4 also indicates the
surface 69 that contacts the recipient's skin for injection of the
medicament. The ampule 25 is expendable and can be easily installed
on the injector assembly by rotating the retainer clamp 22 that is
detented 26, on to the housing 21 of the injector assembly. FIG. 5
shows an end view of the injector assembly and end cap 28, with its
attachment screws 76. FIG. 6 provides a cross section view of said
housing 21, and indicates the two legs of the slide frame 45 as
they straddle the vacuum piston 35.
[0214] FIG. 7 provides a sectional view through the housing, and
shows the routing and passages through the suction manifold 72. The
manifold suction passages 73 supply the necessary vacuum for
extracting the interlock piston rod 36 from release arm 55 with a
small incoming vacuum for movement of the piston rod 36 into the
injector assembly 20. The suction manifold system is comprised of
machined vacuum ports 129 in the housing structure to receive the
vacuum pressure from the vacuum piston 35 and conduct a vacuum
through ported suction passages 73 in the structure within the
vacuum piston chamber 123 to the interlock piston chamber 127 and
to the suction tubes 71 that interface with the ampule 25 the
suction passages are sequentially opened and closed by positioning
of the interlock piston 126, and a pair of suction tubes that
conduct the suction from the machined-in structure suction passages
to the suction ports 63 in the ampule 25.
[0215] The injector 20 operating sequence starts by squeezing the
handle 30 without an ampule 25 being installed. This causes the
drive rod 43 to be pulled back and latched in the cocked position
with the compression drive spring 42 compressed between projecting
ring 120 and annular abutment surface 124 at the rear end of spring
chamber 128. Drive rod latch 48, which catches and draws drive rod
43 back, is spring loaded up and away from drive rod 43 and is only
in position to grab the drive rod 43 when in the full forward
position due to spring ramp 50. If drive rod 43 has been released,
latch 48 will catch the lip of drive rod retention ring 59 and will
pull the drive rod 43 back as the handle 30 is squeezed. Latch 48
is provided with a notch 125 in its underside for this purpose.
Preferably, drive rod retention ring 59 has a small concave
depression in the forward face to engage the notch 125 of drive rod
latch 48 and hold it in place while the handle 30 is squeezed. Upon
full retraction of drive rod 43 and engagement of projecting ring
120 with release catch 44, drive rod latch 48 disengages from
retention ring 59 and is pivoted upward by torsion spring 53 to
clear retention ring 59 when drive rod 43 is released.
[0216] With the drive rod spring 42 compressed, an ampule 25 is
slid into position and ampule retainer clamp 22 is tightened which
brings ampule 25 up against seals 70 in the bottom of the injector
nose with the ampule locking tabs 61 engaged with the injector
structure. The injector 20 is then placed into position with the
ampule 25 on the patient's skin and the handle 30 extended. The
handle 30 is squeezed again. Since the drive rod 43 is already back
in the cocked position, the drive rod retention ring 59 will not be
in position for the drive rod latch 48 to catch on when the handle
30 is extended and squeezed again. As the handle 30 is squeezed the
second time, the vacuum piston 35 creates a vacuum in cylinder 123
which is conveyed to suction ports 63 in ampule 25 by suction
passages 73 and suction tubes 71. This vacuum stretches the skin
tight against the ampule 25 and, when a good seal to the skin is
obtained, will cause the interlock piston rod 36 to retract from
interlock hole 80 in release arm 55, thereby releasing button 23
for operation. With the handle 30 squeezed, the release button 23
is pressed thereby camming release arm 55 downward which lifts
release catch 44 to disengage from projecting ring 120 thus
allowing spring 42 to push drive rod 43 into the ampule 25
providing the force necessary to eject the medicament 31 from the
ampule 25 through orifice 66. The button 23 is then released and
the handle 30 is returned to the extended position thereby
releasing the vacuum and allowing the injector to be pulled away
from the skin. Simultaneously, interlock piston rod 36 is forced
forward to again engage interlock hole 80 in release arm 55 and
lock injector 20 against inadvertent operation. Returning to the
start position of the operating sequence, the handle is squeezed,
thereby latching and pulling the drive rod 43 back so that the
spent ampule can be ejected and replaced with a full one.
[0217] A second embodiment of the injector assembly is shown in
cross section in FIG. 8 and FIG. 9. For convenience and to avoid
confusion, like parts are given the same reference numerals
throughout where their function and operation are duplicated or
repeated. The major difference between the two embodiments is that
the former embodiment utilizes manual operation by the rotation of
a hand operated handle 30, while this embodiment utilizes external
air supplied power for some of its functions. As discussed above,
the primary embodiment utilizes the manual extending downward and
retracting of the handle to actuate a large piston 35 to create a
vacuum that is utilized for ensuring that the recipient's skin is
in direct contact with the injector's injection orifice 66. This
manual mechanism also actuates a means for preventing accidental
activation of the injector and a means for compressing the impulse
drive spring 42 to a lock position, ready for release by the
operator pushing downward on the activation button 23. In this
second embodiment of the invention, an external source of
pressurized air provides a means whereby the mechanical operations
of cocking the drive spring 42 and drive rod 43, generating a
vacuum and activating and deactivating the locking safety mechanism
are substantially automated so as to occur in response to movement
of a trigger assembly 89. The vacuum assist is achieved by the
operation of a valve 100 that is controlled by a trigger assembly
89. Movement of the trigger one way, opens the valve for pressure
to travel up to a large return piston 83 in extension housing 102
on the rear end of injector housing 21, that pulls back on the
vacuum piston 35 to create a vacuum and initiate the same functions
achieved by the previous handle movement, connection of the return
piston 83 to the vacuum piston 35 being by means of connecting rod
82 passing through the end wall of extension housing 102.
Activation of the trigger in the opposite direction closes off the
outside pressure source and, in turn, shuts down the vacuum assist
function provided by the return piston 83. FIG. 8 and FIG. 9 show
this new embodiment in two positions during the injection
operation. This embodiment of the needle-free jet injector utilizes
external air pressure for activating and sequencing the injector
components. The injector 20 is provided with a trigger assembly 89
that is operated by the operator's finger for initiation and
movement of an air valve 100 in the injector 20, that opens and
blocks externally supplied air pressure from exterior source
entering through fitting 49 to a large return piston 83 that is, in
turn, connected to the vacuum piston 35 by connecting rod 82. The
vacuum piston 35 functions as described in connection with the
previous embodiment and provides the vacuum for interlock functions
of the release button 23 and the release catch 44 to initiate
injection of the medicament. The vacuum piston 35 is moved by the
return piston 83 to create a vacuum at the interface contact
surface of the recipient's skin and the ampule 25 containing the
medicament The trigger assembly 89 is operated by the injector
operator's finger applying a squeezing motion to move the trigger
89 upward, toward the injector activation frame 87 thereby causing
the trigger assembly 89 to push against a push rod 90 which
actuates a valve 100 to sequence air pressure to enter the injector
from the outside air supply through source fitting 49. The push rod
90 travels fore and aft in a machined support fitting 95 that is
attached to the underside of the injector assembly and is retained
within the support fitting 95 by a threaded bushing 105 at the end
adjacent to the trigger 89 which provides a means for sealing and
retention of the air pressure within the support fitting 95. An
O-ring seal 92 is captured between the bushing 105 and the support
fitting 95, and seals around the push rod 90 where it passes
through the bushing 105 and contacts the trigger assembly 89. A
like O-ring seal 92 seals around the push rod 90 and seals against
the support fitting 95 at the opposite end adjacent to the valve
100. Valve 100 reciprocates in response to fore and aft movement of
push rod 90 and is used to sequence the incoming air pressure that
enters the valve cavity 130 through two cross pressure ports 91
from the air supply. The valve 100 blocks and opens passage for the
incoming pressure to travel into the injector assembly. The valve
seals against an O-ring 101 in one direction and seals against the
previous O-ring 92 in the opposite direction. The push rod 90 is
machined with an undercut 131 to permit air to travel to the valve
100, which than can allow it to pass up into the injector 20, or to
be blocked by the valve 100 and its seal. The position of the valve
100 is controlled by the position it is put in by the trigger
assembly 89. When the trigger assembly 89 is not activated, the
valve 100 is positioned in the air blocked or closed position by a
compression spring 99 that is captured by a spring retention plug
98 threaded into the support fitting 95. When the valve 100 is in
the blocked or closed position any air pressure captured in the
injection on the opposite side of the valve is bled out of the
return spring cavity though a pressure bleed hole 97. An O-ring
seal 96 is installed at the interface air passage 132 joint between
the support fitting 95 and extension housing 102 attached to the
injector assembly. The air passage 132 conveys pressurized air from
valve 100 into extension housing 102 to drive large return piston
83 that is connected to the vacuum piston 35 by a connecting rod
82. Air pressure behind the return piston 83 pulls on the
connecting rod 82 and, in turn, moves the slide frame 45 to
accomplish what the handle enacted within the prior injector
assembly. The return piston 83 has an O-ring 84 for piston sealing
and a compression spring 85 located between return piston 83 and
spring retention cap 94 for the return function of the return
piston 83. The compression spring 85 is captured in a pocket 133 in
the return piston and in a pocket 134 in the spring retention cap
94. Air captured between the retention cap 94 and the return piston
83 is bled out of the cavity through a bleed hole 97. The retention
cap 94 is attached to the end of extension housing 102 with
retention screws 86. The air pressure into the pressure side of the
return piston 83 enters through a port 135 machined in the
extension housing 102 and connecting with air passage 132. Plug 93
closes the end of port 135 into vacuum piston cylinder 123. The
extension housing 102 is provided with an O-ring seal 81 for
sealing pressure around connection rod 82 and preventing air bleed
into vacuum piston cylinder 123.
[0218] Whereas in the manual embodiment of the injector 20 drive
rod 43 is a single piece, the present embodiment includes an
alternative structure where the drive rod 43 is divided into two
sections, drive rod portion 43' and drive rod portion 43'', with an
absorbing spring between them. The rearward portion, drive rod 43'
includes retention ring 59 with compression drive spring 42
surrounding the shaft between retention ring 59 and a drive
cylinder 78 at the forward end of drive rod portion 43'. Separated
from drive cylinder 78 is forward drive rod portion 43'' which
enters ampule 25 when injection occurs. To ensure that drive rod
portion 43'', when driven by the large drive spring 42, does not
unduly impact the ampule plunger 65 and cause a problem on
injection of the fluid, a small compressing spring 77 is installed
between the rearward end of forward drive rod portion 43'' and the
drive cylinder 78. This compressing spring 77 ensures that the end
of the drive rod portion 43'' is in constant contact with the
ampule plunger 65 prior to and during injection, thereby avoiding a
hard impact between drive rod portion 43'' and ampule plunger 65
when the injector is initiated. Compressing spring 77 absorbs the
initial shock when release catch 44 is rotated to release position
and the tooth release catch 79 disengages with the drive cylinder
78 releasing drive spring 42. The result is that the force of the
drive rod portion 43'' on ampule piston 65 is constant and the
medicament fluid is driven out of the ampule 65 with a smooth high
energy force supplied by the large drive spring 42. This
alternative, two part drive rod 43 may also be applied to the
previous manual embodiment of the injector. FIGS. 10A and 10B
provide views showing the connection of the external air supply to
the injector and the related manifolding of air passages in the
injector.
[0219] In a further alternative, the functions of the foregoing
pneumatic system may be achieved with an electronic solenoid, or
similar electrical or electromagnetic device, powered by batteries
or other electrical source. In such an alternative, the solenoid
would occupy the space in extension housing 102 in place of the
pneumatic piston 83, the plunger of the solenoid being attached to
connecting rod 82. A battery pack providing power for the solenoid
may be located under the housing 21 in place of support fitting 95,
and electrically connected to the solenoid through a switch
operated by the trigger assembly 89 or a switch located elsewhere
on the housing 21. The operational steps of such an alternative
would be the same as the pneumatic embodiment described herein.
[0220] Although the preferred embodiment of the injector employs
the mechanical compression spring and latch mechanisms to provide
the driving force of the impact impulse mechanism, it is certainly
within the scope of the present invention to provide the injector
in a form that is totally pneumatically or electronically operated.
In such modifications, the compression drive spring and mechanical
cocking and latching mechanisms would be replaced by equivalent
pneumatic and electrical, electronic or electromagnetic actuators
to drive both the drive rod 43 and the vacuum piston 35.
[0221] In a totally pneumatic alternative, the chamber in which the
drive rod latch 48 operates to engage the retention ring 59 on the
end of the drive rod 43 would be modified to form a pneumatic
cylinder with retention ring 59 modified to form a pneumatically
actuated piston with drive rod 43 attached. Appropriate porting
would be provided for directing a pneumatic fluid, such as
compressed air, to either side of the piston in response to
actuation of an appropriate valve, thereby reciprocating the
pneumatic piston and the drive rod 43. In addition, means to adjust
the pneumatic force may be included thereby providing adjustment of
the driving force of drive rod 43 against plunger 65 for
intradermal, subcutaneous or intramuscular injections.
[0222] In a totally electronically operated injector it would be a
simple matter to replace the drive spring 42 with an electronic or
electromagnetic actuator, such as a push-pull solenoid, where drive
rod 43 forms the reciprocating core. In this alternative, actuation
of the solenoid would result in reciprocation of the drive rod 43.
With a variable power solenoid and appropriate voltage regulating
means, the driving force generated by the solenoid may be adjusted
for subcutaneous, intradermal or intramuscular injections.
[0223] Turning now to the ampule 25, this is a key element of the
injector device of the present invention as it is the part which
holds the medicament to be injected and interfaces with the
injector to apply suction generated by the injector to the skin in
order to draw the skin tight for proper injection. The ampule 25
further interfaces with the injector to provide proper functioning
of the safety interlock in the injector since release of the
interlock requires establishing a fill suction on the system which
cannot be achieved without the ampule 25. With the ampule 25 and
injector 20 combination of the present invention it is now possible
to achieve needle-less injection of medicament intradermally,
subcutaneously or intramuscularly at any angle relative to the
surface of the skin.
[0224] The basic disposable, pre-filled ampule of the present
invention is shown in FIGS. 11, 12 and 13 and provides containment
for the medicament and means for attachment to the injector and
interface with the vacuum system. The ampule body 67 is preferably
made of plastic, glass or equivalent materials or combinations
thereof that are suitable for medical use, and is provided with a
cylindrical or other shape bore chamber 62 for containing the
medicament Dosage markers 141 are provided on the side of the
ampule 25 at the chamber 62 to indicate the amount of medicament in
the chamber 62. At the forward end of the bore chamber 62 is the
outlet orifice 66, while the rear end of the chamber 62 is closed
with an internal ampule plunger seal 65 that captures the
medicament inside its chamber. The plunger seal 65 is contacted by
the drive rod 43 when the injector is actuated and is pushed
forward within the chamber 62 to eject the medicament through the
orifice 66.
[0225] The shape of the ampule 25 is significant for proper
functioning of the injector system, particularly for achieving
intradermal injection. In that respect, the body 67 of the ampule
25 is structured such that the nose portion 136 is thinner than the
bore chamber portion 137, resulting in a vertical offset 138, or
step face, to the lower surface of the ampule 25 as shown in FIG.
11 and 13. This offset 138 effectively creates a pocket 139 in
front of the orifice 66 into which the skin surface can be readily
drawn by suction from the injector applied through suction ports
63. In addition, the offset 138 of the lower surface permits
ampules to be formed for intradermal, intramuscular and
subcutaneous injection that can be used with the same injector 20
simply by changing the thickness of the nose portion 136 of the
body 67 while the position of the bore chamber 62 relative to the
upper surface of the body 67 remains the same. Thus, an ampule with
a thin nose portion 136 will have a greater offset 138 such that
the effective level of the chamber 62 will be deeper and more
suited to subcutaneous or intramuscular injection, whereas a
thicker nosed ampule will have a lesser offset 138 and be suitable
for intradermal injection. In this manner, the different ampules
can be used with the same injector since the drive rod 43 of the
injector and the plunger seal 65 in the bore chamber 62 will always
be at the same relative height. This relationship can be seen by
comparing FIG. 24, which shows an ampule 25 with a thick nose
portion 136 being used for intradermal injection, with FIG. 26,
which shows an ampule 25 with a thin nose portion 138 being used
for subcutaneous injection.
[0226] In a further embodiment, the underside of the ampule
immediately surrounding the lower end of the suction ports 63 is
preferably formed with a depression or well 140 with the end of the
suction port 63 located at the deepest point. This well 140
improves the effect of the suction against the skin and assists in
achieving lift of the skin into the pocket 139. It is particularly
advantageous for intradermal injections. In ampules having a single
suction port 63, the well 140 is preferably circular, whereas in
ampules with two or more suction ports 63, individual wells 140 can
be formed with each port 63 or a single well 140 accommodating all
ports 63 in the ampule can be formed as shown in FIG. 12.
[0227] FIG. 12 shows a plan view of the underside of an ampule 25
with two suction ports 63 and a single well 140 encompassing both
ports. FIG. 13 shows a longitudinal cross-section view of the
ampule 25 with the chamber 62 contoured 68 on its inner surface to
provide a precision throat to aid in acceleration of the medicament
by reduction of the fluid drag when the ampule 25 receives an
impact impulse from the spring loaded drive rod 43 of the injector
20. This reduction of the fluid drag increases the acceleration of
the piston 65 resulting in a faster pressure rise and injection of
the medicament for the relative force of the compression drive
spring 42. Therefore, the medicament 31 is driven out of the ampule
25 with a known controlled impact impulse force.
[0228] In addition to the difference in offset 138 resulting from
the relative thickness of the nose portion 136 of the ampule body
67, the position and location of the orifice 66 center line
relative to the underside plane 69 of the vacuum port 63 can be
varied further tailoring the ampules for interdermal, subcutaneous
or intramuscular injection medicaments. This also allows injection
horizontally or vertically or at any variation of angle
therebetween, whether laterally or skewed, through human or animal
skin to predetermined depths in the skin layer 64, the dispersement
of the medicament in injections being controlled by variation of
the angle of the orifice 66 to the vacuum port level plane 69 and
the centerline of the ampule. In addition, multiple orifices can be
provided to facilitate injection of larger doses or wider injection
patterns. As noted previously, the ampule 25 includes locking tabs
61 on each end for engagement with and latching to the injector 20.
The locking tabs 61 also serve to correctly position and retain the
ampule 25 on the injector 20 for accurate engagement of the suction
ports 63 with the vacuum suction tubes 71 and alignment of the
drive rod 43 with the chamber 62 and plunger 65. The interface
between the surface of the ampule and the suction tubes 71 is
sealed by vacuum port seal 70 so as to ensure proper suction
through ports 63 to engage recipient's skin for stretching the skin
64 between ports 63 for the medicament injection into recipient's
skin 64.
[0229] In addition to being prefilled, the ampule 25 may be filled
with medicament 31 from an external supply by use of an adaptor
assembly 103, shown in FIG. 14, that holds the ampule 25 and seals
it for filling the medicament through a rubber seal 104 in the
adaptor that aligns with and permits filling of ampule 25 through
its orifice 66. The adaptor 103 comprises a housing having means to
receive and hold the ampule 25 so that the orifice 66 is in
registration with a passage 115 through the rubber seal 104. A
standard Luer connector 142 provides a means for attachment of a
filling syringe.
[0230] An alternative ampule embodiment incorporating means to
permit direct filling of the bore chamber 62 with medicament is
shown in FIGS. 15 through 18. In this embodiment, the ampule is
provided with a filling port 143 in the upper surface of the ampule
25 that is closed by a resealable rubber stopper 106.
[0231] FIG. 16 shows an unfilled ampule 25 in which filling port
143 connects with bore chamber 62 through passage 115. A plug 118
closes orifice 66 and protective coverings 107 and 108 maintain the
sterility of the ampule surfaces and interior.
[0232] FIG. 17 shows the operation of filling the ampule of this
embodiment. In this operation, a probe 111 on a nozzle 110 is
inserted through the stopper 106 in the filling port 143 of the
ampule 25. The nozzle 110 includes a shoulder stop 116 that bears
on the upper flat surface 114 of the ampule 25 and locates the
probe 11 correctly for the medicament filling. Air must first be
evacuated from the ampule passage 115 and the air space 113 within
the ampule 25. This is accomplished with the use of syringe 109 and
its retraction handle 112 to draw the air out prior to filling the
ampule 25 with the medicament. Removal of the probe 111 allows the
plug 106 to reseal thereby sealing off the passage 115 and space
113 containing the vacuum. The probe 111 of a nozzle 110 on a
syringe 109 containing medicament, or the original syringe 109 now
containing medicament, is reinserted through the stopper 106 and
the is used to fill the ampule 25 with a prescnbed medicament after
air evacuation. The pressure of the medicament being injected
through probe 11 and passage 115 into space 113, pushes plunger 65
rearward in bore chamber 62.
[0233] FIG. 18 shows a means for plugging of the ampule orifice 66
with a plug 118 when filling the medicament. Plug 118 contains an
enlarged head 119 for ease of installation and removal with a
capture pad 117 to seal against the surface of the ampule 25 and to
prevent the plug 118 from being sucked into the orifice 66. A
protective outer doubler covering 121 serves as a means to prevent
the plug 118 from being driven out of the orifice 66 during
filling. All other openings in the ampule 25 are protected with
coverings 107 and 108 to maintain full sterile conditions within
the ampule 25 and provide for removal and disposal of the ampule
orifice plug 118 when protective covering 108 is removed.
Preferably, protective coverings 107 and 108 include tabs which may
be grasped for easier removal of the shields from the ampule
25.
[0234] Referring to the drawings, the preferred embodiment of the
invention illustrated in FIG. 1 and FIG. 2 shows the envelope of
the needle-free injector top view and side-view respectively. The
injector assembly 20 comprises a housing 21 that holds the injector
assembly components which are actuated by an external handle 30 and
a release button 23, shown in the top view. FIG. 2 illustrates the
means for installation of the medicament filled ampule 25 into the
injector 20 and provides access panel 27, end cap 28, and insert
fairing 74 as removable units for assembly and service of the
injector.
[0235] FIG. 3 and FIG. 4 provide a cross section view of the
injector assembly with the handle 30 in both a rotated up and a
rotated down position and the resultant position of all of the
components contained in the housing 21 respectively. This
embodiment covers the use of a single prefilled ampule 25 and shows
how it is captured in the injector assembly. The ampule 25 has
projecting tabs 61 that engage a notched cavity in the insert
fairing 74 at one end are and positioned and retained against the
nose of the housing 21 at the other end with retainer clamp 22 that
pivots outward away from the ampule 25 to release it and provide
for replacement after the ampule 25 has been used. The ampule 25
includes at least one vacuum suction port 63 for interfacing with
the injection recipient's skin. The ampule 25 installation in the
injector 20 positions the ampule 25 under and against a seal 70
that provides sealing between the ampule 25 and a pair of suction
tubes 71 that are utilized to convey a vacuum to the ampule vacuum
ports 63. The suction tubes 71 at their opposite ends interface
with a machined-in manifold 72 in the housing 21. The ampule
retainer clamp 22 is retained in the ampule capture position with a
detent projection on the retainer clamp that engages a small pocket
in the housing 21 and, when the retainer clamp 22 is in the ampule
retention position, the clamp 22 snaps into the pocket for firm
retention. On release of the clamp 22 it is rotated around the
upper detent pocket for ampule removal.
[0236] To eject medication fluid 31 out of the ampule 25, a drive
rod 43 travels in a bored hole in the housing 21 structure and is
driven into a chamber opening in said ampule 25 contacting a
plunger 65 therein to force under pressure the fluid out of the
ampule 25 through an orifice 66. The drive rod 43 is driven into
the ampule 25 by a large compression drive spring 42 that applies
load against a projecting ring 120 on the drive rod 43 and at the
opposite end against an abutment surface 124 of the housing
structure. To compress the drive spring 42, the injector assembly
is provided with handle 30 that stradles the assembly and pivots
around a pinned pivot 24. When the handle 30 is rotated up toward
the housing 21, the compression spring 42 is compressed and is
retained at the preloaded compressed location by a release catch 44
that pivots around a pin 58 containing a torsion spring 53. The
torsion spring 53 preloads the release catch 44 down to readily
latch the drive rod 43 when the projecting drive rod ring 120
passes by the tooth 79 of release catch 44.
[0237] To compress the compression spring 42 that encircles the
drive rod 43, the drive rod 43 also has, at its rearward end
termination, retention ring 59 that is used by drive rod latch 48
to pull on the drive rod 43 and compress the compression spring 42
in response to upward rotation of the handle 30. To achieve this
compression and loading up of the compression spring 42 when the
handle 30 is rotated upward, the handle 30 connects to a link 40
that has pivot points 41 and 60 at each end and connects to slide
frame 45 that slides in machined grooves in the housing 21. The
slide frame 45 is moved horizontally in the grooves by the handle
30 pushing the link 40 that in turn moves the slide frame 45. FIG.
3 and FIG. 4 illustrate the two positions of the slide frame 45 and
the handle 30. An upright leg on the slide 45 is attached to the
drive rod latch 48 that is used to pull the drive rod 43 and
compression spring 42 to the compressed loaded energy stored
condition. The drive rod latch 48 pivots around a pivot point pin
52 that holds and engages a connecting link 47 and a torsion spring
53 that biases the drive rod latch 48 upward to the unlatched
position to ensure that drive rod 43 will be released when the
injector 20 is actuated.
[0238] To ensure that the drive rod latch 48 will rotate downward
against the torsion spring load the drive rod latch 48 is guided
down to the latched lock position with a ramp 50. The ramp 50 is
retained in the housing structure 21 with two roll pins 51 and the
ramp 50 is sloped to match the angular end termination of the drive
rod latch 48. The drive rod latch 48 includes a projecting hook
surface on the opposite side of the latch to catch and hold the
drive rod retention ring 59 for pull back. The drive rod retention
ring 59 preferably has a concave depression in the forward face to
ensure that the projecting hook of the drive rod latch 48 will stay
engaged while the handle 30 is squeezed to pull the drive rod 43
back. When the release catch 44 is released, the compression spring
42 drives the drive rod 43 into the ampule 25 and injects the fluid
out of the orifice 66 in the ampule 25. To minimize impact noise of
the drive rod projecting ring 120 and compression spring 42
striking an end stop, the forward side of the drive rod projecting
ring is provided with a plastic or rubber washer 75 for noise
deadening purposes.
[0239] The connector link 47 that is connected to the slide frame
45 is connected at its opposite end to a pin 54 that engages an
extension 46 on a piston 35 that provides a vacuum for the ampule
vacuum ports 63. When the slide frame 45 is moved horizontally in
the machined grooves in the housing structure, the connecting link
47 moves the piston in and out in its cylinder 123. To achieve a
vacuum behind the piston 35, the piston 35 includes an O-ring seal
34. The vacuum created is transmitted through suction passages 73
in the structural manifold 72 to the suction tubes 71 and, in turn,
to the vacuum ports 63 in the ampule 25 as shown in FIG. 7. The
vacuum created by the movement of the piston 35 retracts an
interlock piston rod 36 that provides a means for locking and
unlocking a release arm 55. Two vacuum port openings in the
manifold 72 cycle the interlock piston rod 36 back and forth when
interlock is required. The interlock piston 126 is provided with an
O-ring seal 37 and a retainer ring 39 controls the length of its
movement stroke and captures it in its cylinder 127.
[0240] The interlock piston rod 36 extends into the release arm 55
for locking and retracts out of the release arm 55 for unlocking.
The release arm 55 pivots about a pivot pin 54 that includes a
torsion spring 33 that positions the arm 55 for engagement with the
piston rod 36. When the release arm 55 is in the horizontal
position, as the result of torsion spring 53 load, the release arm
55 rests against the bottom surface of a release button 23 that is
held in the housing 21 with a snap ring 32. When the release button
23 is pressed down by the operator it presses down on the release
arm 55 and rotates it, which in turn drives the release catch 44
upward to disengage from the drive rod 43, which is then driven
into the ampule 25 by the compression spring 42 and injects the
medicament into the skin tissue of the recipient.
[0241] The ampule 25 is illustrated in FIG. 11 side view and FIG.
12 shows a top view of the ampule 25. The ampule 25 is manufactured
from one or more of a variety of plastics, or glass, or equivalent
medical grade materials. The ampule 25 has at least one vacuum port
63 for use in positioning, stretching and holding the recipient's
skin 64. The ampule 25 further has at least two locking tabs 61 and
an internal cylinder bore chamber 62 for containment of the
preloaded medicament. Dosage markers are provided on the outer
surface of the ampule 25 adjacent to the bore chamber 62. Contained
within the bore chamber 62 is an ampule plunger 65, shown in FIG.
11 that captures and contains the medicament within the bore
chamber 62 and transfers the force of the drive rod 43 to the
medicament to eject the medicament from the ampule 25 through the
orifice 66. The bore chamber 62 is preferably contour shaped 68 to
enhance the injection process. The ampule 25 and the injector 20
are unique in that the ampule 25 uses a vacuum produced by the
injector 20 to stretch and properly hold the recipient's skin for
the medicament to be injected into the skin. Stretching the skin
increases permeability which reduces the amount of energy required
to inject fluid into a tissue. Injecting the fluid horizontally to
the skin allows controlled positioning of the tissue for ID, Sub-Q
and IM injections. The bore 62 and orifice 66 are designed to
accelerate the fluid with minimal drag by a refined throat contour
68. The size and length of the ampule's bore are also optimized to
minimize turbulent flow and thus drag and this will reduce pain and
energy required to penetrate the epidermal tissue. This process of
injection of medicament fluid into the tissue spreads the particles
of the medicament over a larger area than using a needle syringe
and, in turn, decreases the local pressure in the tissue and
eliminates leakage of the fluid from the injection opening in the
tissue, which in turn reduces possibility of spreading
infections.
[0242] A further embodiment of the invention is illustrated in FIG.
19 which shows the side view of the injector 20 of the present
invention adapted to receive and fitted with a multiple ampule
assembly 200. The function, operation and internal components of
the injector 20 are the same as those presented previously in the
said single ampule embodiments with the exception of the ampule,
its attachment to and retention on the injector 20 and the
technique of ampule replacement. FIG. 12 illustrates a cross
section view of the multiple ampule injector assembly with manual
embodiment single ampule injector components. The air powered
embodiment may be similarly modified to receive the multiple ampule
assembly 200. Since the mechanical operation of the manual and air
powered injectors 20 is the same as described previously herein,
the description thereof will not be repeated except as necessary to
for a clear understanding of the multiple ampule embodiment.
[0243] The multiple ampule injector housing 201 comprises a
rotatable multiple unit cartridge 205 that contains multiple
medicament filled ampules 25 molded into a plastic or equivalent
material cylinder 222 as shown in FIG. 21 and FIG. 22. The cylinder
222 is rotatable around a center shaft 206 as shown in FIG. 20 and
FIG. 21. The cylinder 222 is manually rotated by a rotation knob
208 rotatably attached to the end of the shaft 206. The cartridge
205 containing the ampules 25 is keyed to the shaft 206 by a sleeve
209 to provide a means for rotation and positioning of the ampules
25 for fluid injection. A position detent 207 is installed in the
injector housing 21 and positions and detents into a series of
pockets 204 in the rim of the cartridge 205. In addition, a similar
detent 214 in the injector housing 21 engages an annular groove 213
adjacent to the end of the shaft 206 to capture and hold the
multiple unit assembly 200 on to the end of the injector 20.
Preferably the detents 207 and 214 are ball 215 and spring 216
mechanisms as shown, but other detent mechanisms providing similar
function may be used.
[0244] The rotation knob 208 is keyed and retained on the sleeve
209 with a knob capture pin 223 so that when the knob is rotated it
rotates the cartridge 205 in the housing 201 around the shaft 206
but does not rotate the shaft 206 itself. The sleeve 209 attached
to the knob 208 keys in the cartridge 205 and turns it to the
various ampule positions whereupon the position detent 207 engages
the pocket 204 for that position and holds the ampule 25 in
registration with the drive rod 43.
[0245] In the cartridge 205 of the multiple unit 200 each ampule 25
contains a set of vacuum ports 203, preferably two, but at least
one, and an internal cylinder bore chamber 62 for containment of
the preloaded medicament. As with the single ampule embodiment,
each ampule 25 of the multiple unit 200 is provided with dosage
markers on its outer surface. Also, each ampule 25 contains within
its bore chamber 62 an ampule plunger 212 that captures and
contains the said medicament. Similarly, the bore chambers 62
duplicate the contour shape, size, length and configuration as
presented in the prior single ampule embodiment and, therefore, the
injection procedure, method of injection and results of the
injection are identical.
[0246] The multiple unit assembly 200 contains a similar suction
tube 210 and a seal 211 for interface with each ampule that is
positioned for fluid injection. A stepped surface on the
cartridge's sleeve 209 bears down on the suction tube 210 to
enhance the seal 211 interface between the suction tube 210 and the
ampule 25. The suction tube 210 connects to the injector's manifold
system in a manner identical to the previous embodiments.
[0247] On the outside surface of the multiple unit housing 201
there is a window 221 that reveals by means of an electronic code
219 and sequential number 222, the status of the various ampules 25
in the cartridge 205. This data reveals the medicament and the dose
used, date of filling, name of the supplier laboratory and/or other
pertinent information. As with the single ampules, each individual
ampule of the multiple unit may be protected by a removable tab 220
prior to use.
[0248] In use, a multiple unit ampule assembly 200 having the
desired medicament preloaded in the ampules 25 will be selected and
installed on the injector 21 by insertion of the end of shaft 206
into a blind shaft receiving hole 218 bored in the end of injector
housing 21 until detent 214 engages the groove 213 in the end of
shaft 206, thereby holding multiple unit assembly 200 in place. The
engagement of detent 214 and groove 213 is of sufficient strength
to hold multiple unit assembly 200 in place against inadvertent
displacement, but not so strong that the multiple unit assembly 200
cannot be readily removed for replacement another assembly 200.
With the multiple unit assembly 200 in place, knob 208 is rotated
to bring an ampule into position and the injector is operated as
previously described. To ready the injector for the next injection
using the same multiple unit assembly 200, one simply re-cocks the
injector as has been described thereby withdrawing the drive rod
from the now used ampule 25 and rotates the knob 208 to bring the
next ampule into position. When all ampules in the multiple unit
have been depleted, or if a different multiple unit is desired, one
grasps the housing 201 of the multiple unit 200 and pulls it from
the injector.
[0249] While there have been described above the principles of this
invention in connection with specific methods and apparatus, it is
to be clearly understood that this description is simply
illustrative and numerous other arrangements may be devised by
those skilled in the art, which will embody the spirit of the
invention and which fall within the scope of the following
claims.
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