U.S. patent application number 10/209415 was filed with the patent office on 2002-12-05 for hand-piece for injection device with a retractable and rotating needle.
Invention is credited to Hochman, Mark N., Livingston, Troy W., Pettinato, David.
Application Number | 20020183701 10/209415 |
Document ID | / |
Family ID | 27384422 |
Filed Date | 2002-12-05 |
United States Patent
Application |
20020183701 |
Kind Code |
A1 |
Hochman, Mark N. ; et
al. |
December 5, 2002 |
Hand-piece for injection device with a retractable and rotating
needle
Abstract
An injection device is arranged and constructed to
simultaneously rotate a needle during its forward translation as a
therapeutic agent such as a liquid is ejected therefrom. In one
embodiment the injection device is an automatic device including a
pump forcing the liquid through a tube to a hand-piece. The needle
has a first position in which it is disposed within a housing of
the hand-piece, and a second position in which the needle extends
outwardly of the hand-piece so that it can be used to eject the
liquid, with the needle being automatically uni- or
bi-directionally rotated as it is advanced between the first and
second positions. In an alternate positions a syringe is provided
with a barrel, a plunger extending into the barrel to eject the
liquid through the needle, and a plunger which is pushed into the
barrel by the operator. The needle and plunger are arranged so that
as the plunger enters the barrel forcing the liquid to be expelled,
the needle automatically rotates about its axis at the same
time.
Inventors: |
Hochman, Mark N.; (Lake
Success, NY) ; Pettinato, David; (Schaumburg, IL)
; Livingston, Troy W.; (North Brook, IL) |
Correspondence
Address: |
GOTTLIEB RACKMAN & REISMAN PC
270 MADISON AVENUE
8TH FLOOR
NEW YORK
NY
100160601
|
Family ID: |
27384422 |
Appl. No.: |
10/209415 |
Filed: |
July 31, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10209415 |
Jul 31, 2002 |
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09506484 |
Feb 17, 2000 |
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6428517 |
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60133397 |
May 10, 1999 |
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60173374 |
Dec 28, 1999 |
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Current U.S.
Class: |
604/264 ;
128/919; 604/164.01 |
Current CPC
Class: |
B01J 2219/00389
20130101; B01J 2219/00394 20130101; B01J 2219/00585 20130101; B01J
2219/00313 20130101; B01J 2219/0072 20130101; A61M 2005/3289
20130101; B01J 2219/00364 20130101; C40B 60/14 20130101; B01J
2219/00698 20130101; A61M 5/3232 20130101; A61M 5/322 20130101;
B01J 19/0046 20130101; B01J 2219/00495 20130101; A61M 5/00
20130101; A61M 2005/3228 20130101; B01J 2219/00707 20130101 |
Class at
Publication: |
604/264 ;
604/164.01; 128/919 |
International
Class: |
A61M 025/00 |
Claims
We claim:
1. An injection system for injecting a liquid such as a therapeutic
agent into a patient, said system comprising: a source of liquid; a
hand-piece remote from said source and adapted to be held by the
operator during an injection procedure; a-tubing coupling said
source to said hand-piece; said hand-piece including a hollow
housing and a needle supported by said housing and having a first
position wherein said needle is disposed in said housing and a
second position in which said needle is disposed at least partially
outside said housing to provide the injection, said needle being
coupled to said tubing; whereby said needle can be selectively
moved by an operator between two positions, including a first
position in which said needle extends outwardly of said housing and
a second position in which said needle is retracted complete inside
said housing.
2. The system of claim 1 further comprising a first stop
cooperating with said hand-piece to lock said needle in said first
position.
3. The system of claim 2 further comprising a second stop
cooperating with said hand-piece to lock said needle in said second
position.
4. The system of claim 1 further comprising a spring biasing said
needle toward one of Aid first and second positions.
5. The system of claim 4 wherein said spring bias said needle
toward said second position, whereby when said needle is released
from said first position it automatically returns to said second
position.
6. The system of claim 1 further comprising a rotating member
cooperating with said hand-piece to simultaneously rotate said
needle as said needle advances outwardly of said housing.
7. The system of claim 6 wherein said rotating member cooperates
with said hand-piece to impart to it a bi-directional rotation.
8. An injection device for delivering a liquid such as a
therapeutic agent to a patient, said device comprising: a
cylindrical housing; a needle associated with said housing and
adapted to deliver said liquid to the patient's tissues; and a
rotating member associated with said housing and provided to
selectively rotate said needle as said needle delivers said
liquid.
9. The injection device of claim 8 further comprising a tank
holding said liquid, said tank being remote from said housing, said
needle having a first position in which said needle is disposed
outside said housing and a second position in which said needle is
disposed inside said housing, and a tubing connecting said tank to
said needle.
10. The injection device of claim 9 wherein said housing includes a
longitudinal slot and a button sliding in said slot, said button
being coupled to said needle to move said needle between said first
and said second positions.
11. The injection device of claim 10 further comprising a first
locking element that cooperates with said housing to lock said
needle in said first position.
12. The injection device of claim 11 further comprising a second
locking element cooperating with said housing to lock said needle
in said second position.
13. The injection device of claim 12 wherein said button cooperates
with one of said first and second locking elements to release said
needle from said first and second positions, respectively.
14. The injection device of claim 10 further comprising a spring
disposed in said housing, said spring being arranged to bias said
needle toward one of said first and second position.
15. The injection device of claim 14 wherein said spring is
arranged to bias said needle toward said second position whereby
said needle automatically moves to said second position when
released from any position external of said housing.
16. The injection device of claim 9 wherein said housing includes
an inner surface formed with a helical groove and said rotating
member includes a coupling attached to said needle, said coupling
being arranged to engage said helical groove to rotate around a
longitudinal axis of said housing as said needle is moved between
said first and second positions.
17. The injection device of claim 16 wherein said coupling and said
groove cooperate to impart a simultaneous translation and rotation
of said needle.
18. The injection device of claim 16 wherein said coupling is
attached to said tubing.
19. The injection device of claim 8 wherein said housing has a
tubular shape and includes a first and a second wall and is adapted
to hold said liquid, wherein said needle is rotatably supported on
said first wall, said device further comprising a piston disposed
in said housing and arranged to push liquid from said housing
toward said needle when urged toward said first wall; said device
further including a plunger supported by said second wall and
having an end coupled to said piston, said plunger being movable
between two positions and being constructed and arranged to rotate
said needle when said plunger is moved to urge said piston toward
said first wall.
20. The injection device of claim 19 further comprising a carpule
disposed in said housing, said carpule containing said liquid, said
carpule being arranged to transfer rotational motion from said
plunger to said needle.
21. An automatic injection system comprising: a tank holding a
therapeutic liquid; a pump arranged to pump said liquid through a
tubing; a hand-piece associated with said tubing and having a
housing, said hand-piece including a needle having a first position
in which said needle extends outwardly from said housing and a
second position inside said housing; and a control member coupled
to said housing and arranged to selectively move said needle
between said first and second positions, said control member said
control member cooperating with said housing to rotate said needle
about an axis of said housing as said needle is moved between said
first and said second positions.
22. The device of claim 21 wherein said housing has a tubular shape
with two opposed ends and a sidewall with a longitudinal slot and
wherein said control member includes a coupling attached to said
needle and said tubing and a button slidably supported in said
longitudinal slot and coupled to said coupling.
23. The device of claim 22 wherein said sidewall is formed with a
helical groove extending along a longitudinal axis of said housing
and wherein said coupling includes a boss engaging said groove,
whereby as said button is moved by an operator in said slot, the
movement of said button being transmitted to said coupling to cause
said coupling and the needle attached thereto to rotate.
24. The device of claim 23 further comprising a first and a second
stop cooperating respectively with said button to lock said needle
in said first and said second positions respectively.
25. The device of claim 23 further comprising a spring disposed in
said housing and being positioned and arranged to bias said needle
toward one of said first and second positions.
26. The device of claim 25 wherein said spring is positioned to
abut said coupling and is adapted to bias said needle toward said
second position.
27. The device of claim 22 wherein said needle is bonded to said
coupling.
28. The device of claim 22 wherein said coupling includes an
adapter arranged and constructed to removably secure said needle to
said coupling.
29. The device of claim 22 wherein said coupling is hollow and is
arranged to allow liquid to flow from said tubing to said
needle.
30. An injection device comprising: a hand-piece; a needle having a
sharp tip and an opposed base connected to a source of therapeutic
agent, wherein said hand-piece and needle cooperate to allow said
needle to be advanced with respect to said hand-piece in a combined
and simultaneous rotational and translational motion.
Description
RELATED APPLICATIONS
[0001] This application claims priority to provisional applications
serial No. 60/133,397 filed May 10, 1999 and serial No. 60/173,374
filed Dec. 28, 1999.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention pertains to a hand-piece for an injection
device or similar apparatus used to inject a therapeutic fluid into
human or animal tissues, and more particularly to a hand-piece
which includes a needle movable along a longitudinal axis, which
needle is optionally rotating about said axis as well.
[0004] 2. Description of the Prior Art
[0005] It is well documented in both dental and medical literature
that pain, tissue damage and post-op complications have long been
tolerated as negative side effects from the use of existing
hypodermic drug delivery injection systems. The pain and tissue
damage are as a direct result of uncontrolled flow rate in
conjunction with excessive pressures created during the
administration of drug solutions within the tissues. Subjective
pain response of a patient has been demonstrated to be minimized at
specific flow rates during the administration of a drug. Also, it
has been scientifically demonstrated that particular pressures
(excessive without occlusion, per se) for a specific tissue type
will cause damage. It is therefore critical that a specific flow
rate in conjunction with a specified pressure range be maintained
during the delivery of fluids (drugs) when a subcutaneous injection
is given preventing subjective pain response as well as tissue
damage. It is also necessary that this system have the capability
to aspirate under controlled conditions of rate and pressure to
avoid the same negative side effects during fluid movement. U.S.
Pat. No. 5,180,371 to Spinello, incorporated herein by reference,
presented an invention which allowed a rate to be set for the drug
via a hypodermic needle disposed in a hand-piece.
[0006] One of the goals of dentistry and medicine should be to
administer care to patients in the most humane and painless manner.
The sine qua non of any treatment is to produce a desired result
without causing damage or pain to the individual. Therefore there
is an important need in all fields of surgery for an injection
system which can be used to administer a fluid while causing
substantially no pain or tissue damage to the patient.
[0007] Another goal of dentistry and medicine in general is to
insure that during any procedure involving interaction between a
dentist or other care giver and a patient, utmost care is taken to
protect the care giver from injury and/or infection with
diseases.
[0008] The use of hollow-core needles is the standard in drug
delivery in medicine and dentistry. The use of the hollow-core
needle dates back over 150 years when Charles Pravaz, a French
general surgeon, patented such a device. It has been recognized
that the use of hypodermic needles, which activity is endemic in
the field, is one particularly hazardous activity which could cause
injury. More particularly, the use of a hypodermic needle in
dentistry and other medical fields has been shown to put the
operator at risk to inadvertent needle sticks presenting a
potential high risk to infection disease transmission for health
care workers.
[0009] Currently, there are several auto-retraction type syringes
are known that provide increased safety by allowing the protruding
needle to be retracted into a protective sheath after use. However,
current syringes require the use of a palm-thumb grasp during their
use. This type of hand dexterity presents a potential risk of
inadvertent needle stick during entry and withdrawal from the
patient tissues. Other syringes are provided with removable caps.
However, this configuration does not solve the problem in a
satisfactory manner.
[0010] All of these prior art references have either one or more of
the following deficiencies.
[0011] 1) The use of a hollow needle that is rigidly affixed to the
end of a syringe-, tubing or hand-piece. The protruding needle
presents a risk of inadvertent needle stick to the operator.
[0012] 2) Existing auto-retracting syringes and the like require
the operator to use a palm-thumb grasp to operate. This structure
creates an increased risk of inadvertent needle stick to the
operator.
[0013] 3) Existing auto-retracting syringes and the like require
the operator to make use of the hand to physically retract the
needle, thereby, making it difficult and cumbersome to perform.
[0014] Some prior art syringes and needles with sheaths or caps are
disclosed in the following U.S. Pat. Nos.: 5,120,310; 5,188,613;
5.267,961; 5,389,076; 5,423,758; 5,578,011; 5,632,733; 5,637,092;
5,810,775; 5,030,209; 4,911,693; 4,900,310; 4,813,426; 4,795,432;
4,664,654; 4,695,274; 4,966,592; 4,747,831; 4,900,311; 5,411,487;
5,106,379; 5,713,873.
[0015] With the rise of infectious diseases, i.e. hepatitis and
AIDS, protection of the health care workers has become a needed
priority because, as indicated in the medical/dental literature,
inadvertent needle sticks represent a significant risk to our
health care providers. In the past 15 years regulatory agencies
such as OSHA have attempted to improve the use and safety of
needles in the health care industry further accentuating the need
for an effective means of preventing needle sticks.
[0016] In addition, various medical organizations have suggested
and several states have instituted rules for the protection of care
givers while providing injections to patients. More specifically,
rules have been promulgated requiring that injection needles on
syringes be provided which can be easily removed prior to an
injection and re-installed immediately after an injection.
[0017] The proposed invention has been designed to eliminate the
potential of inadvertent needle sticks during and after use.
[0018] Another related problem addressed by the present invention
pertains to the deflection or bending of needles as they are
inserted into the tissues of a patient. This deflection occurs
because the needle is usually flexible because of its relatively
small cross-sectional area and cannot resist effectively the axial
and radial forces present during the insertion. The deflection is
undesirable because it provides additional resistance during the
insertion, to the movement of the needle and makes it difficult to
guide the needle to a particular site. Moreover, if a needle is
deflected, bent or otherwise deformed during insertion, it may
cause more pain to the patient, trauma to the local tissues and
other undesirable effect. It has been discovered (as disclosed in
co-pending provisional application serial No. 60/173,374 filed Dec.
28, 1999), incorporated herein by reference, that these
disadvantages are eliminated or at least alleviated if the needle
is stated about its longitudinal axis as it is advanced along the
axis into the patient tissues. While rotating devices are known
which rotate about their longitudinal axes to allow drilling
through bony tissues, these devices do not allow high level tactile
control during use. Other syringes do not allow the use of a
bi-directional rotational insertion technique to be used during a
power assisted injection process.
OBJECTIVES AND SUMMARY OF THE INVENTION
[0019] In view of the above-mentioned disadvantages of the prior
art, an objective of the present invention is to provide an
injection device having a needle which can be selectively advanced
from a retracted position in which the needle is hidden, toward an
open position in which a therapeutic agent can be administered
effectively, and can be retracted back to the retracted position
before disposal.
[0020] A further objective is an injection device adapted to
provide injection to a selected site and/or tissue by using a
selective bi-directional rotational movement of the needle to
prevent deflection of the needle.
[0021] Yet another objective is to provide an injection device
which allows an operator to advance a needle at a manually
controlled rate and with a hand-piece which is held steadily in a
relatively stationary position with respect to the patient.
[0022] A further objective is to provide an injection device which
can be used repeatedly to advance and retract a needle in a linear,
rotational or bi-directional rotational motion.
[0023] Other objectives and advantages of the invention shall
become apparent from the following description.
[0024] Briefly, an automatic injection device constructed in
accordance with this invention includes a source of fluid to be
injected, a needle, handle with a housing and a coupling used to
selectively advance the needle out of the hand-piece, preferably
under the control of the operator, and once an injection is
complete, to retract it back into the hand-piece. Advantageously,
the needle may be protracted and retracted several times during
multiple uses on the same patient. The device may be a drug
delivery device which serves to inject medicament from a tank or
reservoir. This includes but should not be limited to infusion type
pumps, syringe pumps, such as the Wand (g) made by Miiestone
Scientific of Orange, N.J.
[0025] In one embodiment, of the invention, a spring is provided in
the housing which is arranged to bias the needle. Preferably the
needle is biased toward its retracted position so that if the
needle is advanced to extend outwardly of the housing and then
released, it automatically returns to the retrieved position within
the housing thereby reducing the likelihood that the needle pricks
or otherwise injures an operator, the patient, or anyone else.
Locking members are also provided which are used to secure the
needle in the first--that is--the retrieved position, or the second
position. The coupling may be arranged and constructed to cooperate
with the housing so that as the needle is advanced out of the
housing, it is automatically and simultaneously rotated about its
longitudinal axis. Typically, the needle may be rotated by about
45-270.degree.. Preferably the needle is rotated by about
180.degree.. This may be accomplished, for instance, by providing a
helical groove on an inner surface of the housing and a boss on the
coupling. As the coupling moves through the housing, its boss rides
through the groove and this caming action causes the coupling,
and-the needle to rotate. If the groove is oriented in the same
direction, the rotational motion is uni-directional. The groove can
also be made to change direction one or more times along its
length, in which case the needle undergoes a bi- or
multidirectional motion. The term uni-directional is used to
describe motion in the same sense, e.g., clockwise or
counterclockwise. The term bi-directional is used to describe a
motion that changes sense, e.g., initially clockwise, then
counterclockwise.
[0026] Rotation may also be imparted to a needle affixed to a
standard syringe. In this case, the needle is mounted to one wall
of the barrel using a ball-bearing mounted, or other frictionless
surface. A plunger is coupled to the other side of the barrel in a
manner which forces the plunger to rotate as it is inserted into
the barrel to force liquid from the barrel to be ejected through
the needle. The plunger and the needle are coupled so that the
rotation of the plunger is transmitted to the needle.
BRIEF DESCRIPTION OF THE FIGURES
[0027] FIG. 1 shows a somewhat schematic diagram of an automatic
injection device constructed in accordance with this invention;
[0028] FIG. 2 shows a sectional somewhat diagrammatic view of the
hand-piece for the device of FIG. 1 with the needle in an extended
position;
[0029] FIG. 3 shows a sectional view similar to FIG. 2 with the
needle in the retracted position;
[0030] FIG. 4 shows a sectional view of the needle and a spring
used to bias the needle toward the retracted position;
[0031] FIG. 5 shows a sectional view of the needle and the spring
in the extended position;
[0032] FIG. 6 shows an embodiment of the invention which allows the
needle to rotate about its axis, the needle being in a retracted
position;
[0033] FIG. 7 shows a view similar to FIG. 6 with the needle being
in the extended position;
[0034] FIG. 8 shows an enlarged view of the needle coupling and its
engagement with a spiral groove;
[0035] FIG. 9 shows an enlarged side view of the coupling;
[0036] FIG. 10 shows a side view of a hand-piece according to an
alternate embodiment of the invention wherein the helical groove
has been omitted;
[0037] FIG. 11 shows a top view of a hand-piece according to an
alternate embodiment wherein the slot holding the button or tab has
side wing or wings; and
[0038] FIG. 12 shows a sectional view of a hand-piece according to
an alternate embodiment of the invention
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0039] In order to better understand the purpose of this invention,
a somewhat generic automatic injection device is first described.
In this application the term automatic injection device, as
illustrated in FIG. 1 refers to a device 10 in which a fluid
ejection means such as a pump 12 is used to force a fluid from a
tank 14 under the control means such as a switch 16 into a flexible
tubing 18. The tank may be a vial, a carpule or other known vessels
that could be used to store a therapeutic liquid. The tubing 18
terminates in hand-piece 20 with a needle 22. The various elements
described so far cooperate to allow a nurse, physician, dentist and
other health care professional operator to inject selectively the
liquid from tank 14 into the tissues of a patient (not shown) by
activating the switch 16.
[0040] Importantly, according to this invention, the needle 22 is
movable into and out of the hand-piece 20. In a preferred
embodiment, the needle 22 is normally disposed inside the
hand-piece 20 and is extended by the operator prior to or
simultaneously with the injection. After the injection is complete,
the needle 22 is preferable retracted into the hand-piece 20. In
this manner, the needle 22 is exposed only the short periods of
time that the injection actually occurs, thereby preventing injury
and infection to the operator of the device 10 or other people.
Studies have shown that a person handling a device associated with
a needle is injured during this period.
[0041] Advantageously, the hand-piece 20, needle 22 and the tubing
18 are generally disposable. Moreover, the cap normally provided to
cover the needle is eliminated, so it is no longer required.
[0042] Details of the hand-piece 20 and needle 22 are now discussed
in conjunction with FIGS. 2-9. The hand-piece 20 includes in
accordance with this invention a cylindrical housing 24 with an
internal wall 26, an external wall 28, and two ends 30, 32.
Hand-piece 20 further includes an elongated hollow stem 34 provided
to protect the tubing 18. The tubing 18 which extends through the
stem 34 into the housing 24 and is coupled directly or indirectly
to the needle 20 as discussed more fully below. Stem 34 may be
glued to the housing 24, or may be sized and shaped to form an
interference fit therewith, whereby it can be inserted into the
housing 24 or removed at will.
[0043] Mounted on housing 24 there is a button 36 slidable in a
longitudinal slot 38 extending through the housing. Housing 24 is
provided with a stop 40 at the forward end of slot 38. The rear end
42 of the housing 24 serves as a rear stop for button 36.
Alternatively, a stop similar to stop 40 may be provided on the
external wall 28 of housing 24. Button 36 includes two spring arms
44, 46. These arms extend in the longitudinal axis of the housing
24 and are turned upward, or away from surface 28 at their tips.
These arms 44, 46 are somewhat flexible and cooperate with the stop
40 and end wall 42 to limit the movement of button 36 in slot 38.
More particularly, as button 36 is reciprocated by an operator in
slot 38, when the button reaches its forward position, the arm 44
rides over the stop 40 and then snaps radially inward to form an
interference fit with the stop 40. This position (shown in FIG. 2)
corresponds to the extended position of the needle 20, with the
button 36 being locked. The button 36 can be released by pressing
it downward toward the housing 24, thereby causing arms 44, 46 to
flex upward. The button 36 can then move backward, away from the
front opening 30 because the arm 44 clears the stop 40. When the
button 36 is moved backwards toward stem 34, when its rear arm 46
engages the rear wall 42, the button 36 is locked into the rear
position, and the needle 22 is in its fully retracted position, as
indicated in FIG. 3.
[0044] Button 36 further includes a pin 48 extending downwardly or
radially through slot 28 to engage needle 20. Button 38 can be made
of a high impact plastic material. Its wings 44, 46 can be made
integral with the button 38, or can be made of steel.
[0045] Referring now to FIGS. 4 and 5 (in which the stem 34 has
been omitted for the sake of clarity) the needle 20 is attached to
a coupling 50. This coupling includes a central hollow shaft 52
sized and shaped to connect to an end of tubing 18. Preferably the
tubing 18 is glued or otherwise secured to the shaft 52 so that it
is permanently mounted thereto.
[0046] The coupling also has a circular disc 54 mounted coaxially
on the shaft 52. Spaced axially away from disc 54 there is
cup-shaped adapter 56. Adapter 56 has an outer surface 58 with a
plurality of axially shaped circumferential ribs 60. The disc 54
and adapter 56 are separated by an annular space 62 having an axial
length which is equal to, or slightly greater than the
cross-sectional dimension of pin 48. The button 36 is positioned on
the housing 12 so that this pin 48 extends into the space 62 as
shown. Therefore the coupling 50 and the button 36 are effectively
interlocked so that the coupling 50 can be moved in either
direction along the length of the housing 24 and the button 36 will
move with it (within the length of the slot 38) and vice versa.
However, because space 56 is annular, the coupling 50 may also
rotate around the longitudinal axis of housing 24 without
interference from button 36.
[0047] Typically, needle 22 includes a narrow, thin-walled hollow
shaft 64 and a base 66. In one embodiment of the invention the
needle 22 is configured with the base 66 being mounted on shaft 52
so that it abuts the adapter 50. Base 66 is preferably bonded or
otherwise secured to the shaft 52 and/or the adapter 56. The base
66 is hollow and in communication with the opening in the hollow
shaft 64. Therefore, once the base 66 is mounted and secured to the
adapter 56, the interior of tube 18 is in communication with the
interior of the shaft 64 through the shaft 52.
[0048] Preferably, the end 30 is partially closed with a
disc-shaped end wall 68. This end wall 68 has an opening (not
shown) sufficiently large to allow the needle 22 and its base 66 to
extend at least partially from housing 24, as seen in FIG. 5.
[0049] In one embodiment of the invention, as mentioned above, the
base 66 is bonded to adapter 54. In another embodiment of the
invention, the adapter 54 is a female Luer connector and the base
66 is a male Luer connector, the two connectors cooperating to
mount the needle 22 on the coupling 50 so that the needle 22 can be
attached and removed at will. This feature may be advantageous
during a long procedure the tip of the needle 22 may become dull
and may have to be changed before the procedure is complete.
[0050] In another embodiment of the invention, an optional
compression spring 70 is provided between the end wall 68 and the
coupling 50 in such a manner that normally the spring 70 pushes the
coupling 50, and the needle 22 attached thereto, away from wall 68.
In other words, in this embodiment, the springs 70 urges the needle
22 toward its retracted position.
[0051] Yet in a further embodiment of the invention, shown in FIG.
6, 7 and 8, the coupling 50 is provided with a boss 72 extending
radially, and the inner surface 26 is provided with a helical
groove 74, with the boss 72 being seated with the groove 74 as
shown. In this embodiment, coupling 50 and the needle 22 attached
thereto are rotatable about the longitudinal axis of housing
24.
[0052] The operation of device 10 is now described in conjunction
with the drawings. Initially, it is assumed that device 10 has a
hand-piece which has been provided with a spring 70 and groove 74.
Prior to an injection the needle 22 is disposed in the hand-piece
20 in its retracted position and is maintained in this
configuration by the spring 70. In fact the tubing 18, hand-piece
20 and needle 22 may come in a kit, several kits being made
available for the operator, each with a needle having a shaft 64 of
different nominal lengths (i.e. 20 mm, 25 mm, 30 mm . . . ) In one
mode of operation, the operator initializes the pump 12, positions
the hand-piece 20 so that the hand-piece points to the site or
tissue of interest, activates the switch 16 to start the delivery
of the therapeutic agent, and starts advancing the needle 20 to
cause the needle to slowly extend outwardly of the hand-piece and
coaxially with the longitudinal axis of the hand-piece 20.
Preferably, the hand-piece is sized and shaped so that it can be
held by the operator in the manner of a pencil with his forefinger
being free to rest on and push the reciprocate button 36. However,
before the needle can be pushed forward, it must be unlatched
because it is locked in the retracted position by the cooperation
between arm 46 and rear wall 32. Therefore the operator must
release the needle 22. This can be accomplished by pushing down or
radially inwardly on the button 36. This action causes the button
36 to bend arms 44, 46 upward thereby releasing arm 46 from rear
wall 32. The needle 22 is now free to move forward.
[0053] As the needle 22 is advancing with respect to the hand-piece
20, the boss 72 rides in a caming action against the helical groove
74 and causes the coupling 50 and the needle 22 to rotate. This
combined advancement or translation of the needle and its
simultaneous rotation is continued until the button 36 reaches the
forward stop 40. At this point the forward arm 44 goes over the
stop 40 and then forms an interference fit with it causing the
button 36 and the needle 22 to lock in the extended position. This
action is felt by the operator as a click and therefore the
operator does not have to keep his eye on the hand-piece. Since the
needle 22 has now been locked in the extended position, the
operator can release button 36 and continue the injection without
moving the needle. The therapeutic liquid from tank 14 is injected
into the patient during or after the needle has been advanced out
of the housing 24 and into the patient's tissues.
[0054] In some situations, an operator may prefer to advance the
needle 22 out of housing 24 before inserting the needle into the
tissues. In this case he just moves the button 36 forward while he
keeps the hand-piece 20 away from the patient until the needle 22
reaches its extended position and is locked into this position. The
operator can proceed to insert the needle 22 into the patient
tissues in a normal manner.
[0055] Once, the injection is completed, the needle 22 can be
retrieved back into housing 24. This retrieval may be accomplished
either while the needle is imbedded into the patient's tissues, or
after it has been withdrawn therefrom. In either case, the needle
22 can be retrieved by pushing the button 36 inwardly or radially
causing the arm 44 to rise and disengage from the forward stop 40.
Once the arm 44 is disengaged, the operator can release button 36.
Since spring 70 is in a compressed state, as shown in FIG. 5,
releasing the button 36 causes the spring 70 to extend axially
through the housing 24 forcing the coupling 50 to move rapidly
backward toward stem 34. Retraction occurs by rotation about the
long axis. Rotation minimizes drug resistance and makes the
retraction more efficient. In his manner, the needle 22 which is
attached to the coupling also moves rapidly backwards and snaps
back into the housing to the retracted position. This operation
takes places very fast thereby avoiding any chance that the
operator will get pricked or otherwise injured by the sharp tip of
needle 22. Since the end of tubing 18 is also attached to the
coupling, the tubing IS slides through the stem 34 and in and out
of the housing 24 as required.
[0056] If the spring 70 is omitted, the needle 22 must be retrieved
into the housing 24 manually using button 36 causing the needle to
rotate upon removal.
[0057] As illustrated in FIG. 4, the coupling 50 is provided with
ribs 68 and disc 54 which arranged and constructed to slidably
engage the inner wall 28 of housing 24. Therefore, as the coupling
24 reciprocates within the housing in a smooth controlled movement
without any radial jitter, thereby giving the operator a solid feel
and ease of operation.
[0058] Preferably, the tubing 18, hand-piece 20 and needle 22 are
all disposable. Health regulation frequently require that
disposable items with sharp tips or edges which may puncture an
attendant must be disposed separately. As indicated in FIG. 9,
preferably the portion of the shaft 52 extending between disk 54
and adapter 56 is provided with a radial groove 76 which may be
about 0.015" deep. At the end of the injection procedure, the stem
34 may be removed from the housing 24, and the housing 24 may be
bent manually to cause the coupling 50 to snap along groove 76. The
disc 54 can now be removed from the housing 24 while the adapter 56
and the needle 24 are retained in the housing 24 by the pin 48. The
housing 24 with the needle 22 can now be disposed as a sharp object
while the remaining portions including tubing 18, stem 34 can be
disposed as standard (i.e., non-sharp) objects.
[0059] In the Figures, the groove 70 is shown as being
uni-directional so that as the needle is advanced, it is rotated by
the groove always in the same direction, e.g. clockwise. In an
alternate embodiment, the groove can be made into axially spaced
segments with adjacent segments being oriented in different senses.
For this arrangement, as the needle is translated along its axis,
it is simultaneously rotated first in one direction, then in the
opposite direction by the respective groove segments. This the
needle can have a uni-directional, bi-directional or
multi-directional rotation.
[0060] As discussed above, the helical groove 74 is optional. If it
is omitted, then the coupling 50 can have a much simpler shape, or
can be eliminated altogether. For example, FIG. 10 shows an
embodiment wherein the tubing 18 abuts the base 66 of needle 22.
The button 36 or in this case, a simple tab 38S extends through
slot 38 and is engaged to the tubing 18. Instead of an end wall 68,
or in addition thereto, an annular spring stop 68A is provided on
the inner wall 28 of housing 24. Spring 70 is in compression
between this stop 68A and the base 66 of needle 22. If the housing
24 is made without the groove 74, as shown in FIG. 10 then the
needle 22 can be advanced and retrieved linearly, i.e., without
imparting to it any substantial rotary motion about its
longitudinal axis.
[0061] In the embodiments of FIGS. 1-9, the button 36 is limited to
a longitudinal motion by the shape of slot 38. FIG. 10 shows an
alternate embodiment of the invention. In this embodiment, the
button 36 or a tab is disposed in a longitudinal slot 36A having a
lateral extension 38B. In this embodiment, after the needle 22
reaches its extended position, the operator shifts the button 36
into lateral extension 38B. The force of spring 70 applied to the
base 66, and hence to tubing 13, forces the needle to be locked in
this position until it is released. If desired, a second lateral
extension 68C may also be added to park the needle in the retreated
position so that it does not move.
[0062] In the embodiments of FIGS. 1-11 a liquid injecting device
10 is described wherein liquid from a separate tank is pumped
through a flexible tubing 18 and hand-piece 20 to needle 22. In an
alternate embodiment of the invention, some of the novel features
of device are incorporated into a standard syringe-type liquid
delivery system. In this embodiment, a syringe 100 is provided
having a barrel 102 having a first end wall 104 with finger tabs
106. A hole 108 is made in the wall with two opposed radial arms
110. Extending through hole 108 there is provided a plunger 112
formed of a rod 114. At one end, rod 114 is formed with a head 116
and a thumb ring 118. Inside head 116 there is a stationary disc
120 and bearings 122 attached to rod 114. Rod 114 is formed with
one or more helical grooves 124.
[0063] At the opposite end, rod 114 is formed with a harpoon 126.
Next to the harpoon, there is a piston 130 with an O-ring 132 and
being attached to rod 114.
[0064] At the other end of barrel 102, there is provided an end
wall 126 with an opening 128. A sleeve 130 passes through the
opening 128 and is provided with two disc-shaped walls 132, 134.
Ball bearings or other frictionless couplings support the sleeve
130 and walls 132, 134 on end wall 126 in a rotatable manner. A
connector 136 is mounted on wall 134 to receive needle 22. When the
needle 22 is mounted on connector 136 by its base 66, a portion 22A
of the needle extends into the barrel 102.
[0065] The syringe 100 is used to eject a liquid such as an
anesthetic disposed in a cartridge 140. This cartridge 140 includes
a glass cylindrical housing 142, with a membrane 144 at one end and
a rubber stopper 146 at the other end.
[0066] The end wall 104 on syringe 100 is removable to allow the
cartridge 140 to be inserted into the barrel 100 with the membrane
144 disposed near end wall 126 and being engaged by wall 132. Once
the cartridge 140 is inside the barrel and an operator is ready for
the injection, the operator mounts the needle 22 on connector 136,
its portion 22A enters into the barrel 102 and penetrates the
membrane 144. Next, the end wall 104 is replaced on the barrel so
that the harpoon 126 penetrates and engages the stopper 146. The
operator then starts the injection by pushing the needle 22 forward
to penetrate the subject tissues. During the forward movement of
the needle, the operator holds the syringe with two fingers on the
tabs 106 and the thumb engaging ring 118 and pushing the rod
forward. During this motion, the rod is slowly advanced into the
barrel 102, forcing the piston into the housing 142. The piston and
the stopper both move forward expressing liquid from the cartridge
140 through the needle 22. Importantly, the positioning of the
groove(s) 124 and tabs 110 in opening 108, the caming action of
tabs 110 on groove(s) 124 causes the rod 114 to rotate around its
longitudinal axis, which also coincides with the longitudinal axis
of the barrel 102. The rotation of the rod 114 is transmitted by
the harpoon 126, piston 128 and O-ring 130 to the cartridge 140 and
then through the end wall 132 to needle 22. Thus the needle 22
rotates essentially in the same manner as the rod 114.
[0067] The rotation imparted to the needle 22 attached to either
hand-piece 20 or syringe 100 is dictated by the pitch and length of
the grooves 74 and 124 respectively. It has been found that
preferably, the needle through its travel should rotate by about
45-270.degree.. More particularly, it has been found that the
rotational movement is most effective when it covers about
180.degree..
[0068] An important advantage of the present invention, is that it
allows a clinician to hold the hand-piece within a grasp similar to
one used for holding a pen or pencils, i.e., between the thumb, the
forefinger and the middle finger. Traditional grasps for injection
devices, such as standard syringes, involve the use of the fore-
and middle finger holding the barrel and the opposed thumb moving
toward the fingers and applying pressure on the piston. This grasp
is not very efficient because it is difficult for a clinician to
hold a syringe steady or to advance it at a slow, controlled rate
while the fingers are moving toward each other. Moreover, it is
believed using this process repeatedly over several hours a day may
cause carpal syndrome. On the other hand, in the present invention,
the hand-piece is held between the thumb and the middle finger. The
forefinger is used to steady the hand-piece, to direct it more
precisely toward the desired tissues and to move the needle. Thus,
the present invention provides a much more ergonomic device.
[0069] The subject invention discloses of a novel approach for
injection systems in which a needle can be presented to the patient
in a retracted state, thereby protecting the operator prior to the
entry of the needle into patient tissues. Once the injection
procedure has been concluded the needle can be withdrawn
automatically back into the protective housing prior to having the
hand-piece being moved away from patient's tissues, thereby
eliminating the exposure of the operator to the unprotected needle
at all times.
[0070] The novel design allows the reuse of a needle on a
particular patient, i.e., subsequent dental injections during the
same appointment can be given for a patient using the same
device.
[0071] The subject invention provides the following advantages over
the prior art:
[0072] A. Allows the needle to automatically retract into the
protective housing.
[0073] B. Allows the operator to advance the needle out of the
housing sheath via manual operator control.
[0074] C. Allows the operator to use a pen-like grasp which has
been shown to have superior tactile control and more ergonomic then
existing configurations.
[0075] D. Does not require extensive hand manipulation or the use
of the second hand to automatically retract the needle.
[0076] E. Allows for reuse of the needle on the same patient during
a given procedure, but eliminates the risk associated with the
re-use of a needle.
[0077] F. Depending on the structure of the hand-piece, the needle
can be subjected to a translational motion or a simultaneous
translational and rotational motion.
[0078] G. Depending on the structure of the hand-piece, the needle
can be subjected to uni-directional, bi-directional or even
multi-directional motion.
[0079] H. The injection process described can be repeated several
times of necessary with ease, with the same or a different
needle.
[0080] This invention represents a major advancement in the safety
and use of hollow-core needles. It discloses a device that is easy
and predictable in operation. The device minimizes or eliminates
the risk potential of inadvertent needle sticks to health care
workers.
[0081] While several embodiments have been described it should be
understood that other modifications can be made to the invention
without departing from its scope as defined in the appended
claims.
* * * * *