U.S. patent application number 11/811847 was filed with the patent office on 2007-10-25 for fluid material dispensing syringe.
Invention is credited to Tan-Cheng Chou, Ingrid Elaine Hohlfelder, Tom Papanek, Chester L. Zdanowski.
Application Number | 20070250010 11/811847 |
Document ID | / |
Family ID | 38620410 |
Filed Date | 2007-10-25 |
United States Patent
Application |
20070250010 |
Kind Code |
A1 |
Hohlfelder; Ingrid Elaine ;
et al. |
October 25, 2007 |
Fluid material dispensing syringe
Abstract
A dental syringe (10) has a needle (11) affixed to a carpule
holder (12), which carpule holder (12) is affixed to a power drive
unit (13). A harpoon (20) is provided to affix the drive unit to
the carpule plunger (32). The harpoon (20) is made of stainless
steel or other hard, corrosion resistant, sterilizable, material.
Harpoon 20 has a unique barb geometry and hardened, knife-like,
edges (21). The syringe (10) may operate to divide the delivery of
anesthesia into two phases. According to the method, during the
first about 10 seconds of the injection, anesthetic is delivered at
an extremely slow rate to maximize patient comfort. The injection
rate then automatically increases to the preprogrammed rate
associated with the injection type selected.
Inventors: |
Hohlfelder; Ingrid Elaine;
(Geneva, IL) ; Zdanowski; Chester L.; (Westmont,
IL) ; Papanek; Tom; (Lake Forest, IL) ; Chou;
Tan-Cheng; (Arlington Heights, IL) |
Correspondence
Address: |
DENTSPLY INTERNATIONAL INC
570 WEST COLLEGE AVENUE
YORK
PA
17404
US
|
Family ID: |
38620410 |
Appl. No.: |
11/811847 |
Filed: |
June 12, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10665787 |
Sep 18, 2003 |
|
|
|
11811847 |
Jun 12, 2007 |
|
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Current U.S.
Class: |
604/154 |
Current CPC
Class: |
A61C 19/08 20130101;
A61M 5/172 20130101; A61C 5/62 20170201; A61M 5/14566 20130101;
A61M 5/482 20130101; A61M 5/24 20130101 |
Class at
Publication: |
604/154 |
International
Class: |
A61M 5/145 20060101
A61M005/145 |
Claims
1. A system for administering an anesthetic into a patient, the
system comprising: a container storing an anesthetic; a needle; and
means for delivering the anesthetic through the needle at a first
predetermined rate for a first predetermined time of between about
30 and 240 seconds.
2. The system for administering an anesthetic into a patient as in
claim 1, wherein the means for delivering the anesthetic further
comprises means for a user to select the second predetermined rate.
Description
RELATED APPLICATIONS
[0001] This application is a Continuation application of U.S.
patent application Ser. No. 09/974,361 (Case MID-38 ABC) filed Oct.
10, 2001, which claims the benefit from Provisional Application No.
60/238917 filed Oct. 10, 2000.
TECHNICAL FIELD
[0002] The present invention is directed toward a syringe for
dispensing a fluid material such as a dental anesthesia. The
invention provides an electronic programmable device indicated for
the injection of local anesthetics for infiltration and nerve block
anesthesia administered prior to, or in conjunction with, dental
procedures, and the like.
BACKGROUND OF THE INVENTION
[0003] Syringes, of any type, are essentially positive displacement
pumps which generate a flow of liquid. While the present
description may employ terms denoting an anetsthetic, including the
word "anesthesia" or the like, it is to be understood that the
present invention has application to the injection of any fluid
into a patient. For convenience, the term anesthesia or its
derivatives may be employed, with the understanding that these
terms will encompass any injectible fluid or liquid, including
anesthetics or medicants of any kind, and are thereby
interchangeably employed herein.
[0004] With all syringe injections, the pressure in the tissue is a
function of the flow rate into the tissue and the rate at which
fluid can be absorbed into the tissue. A slow injection into soft
tissue will generate only a few psi (pounds per square inch) of
pressure. A rapid injection into the periodontal ligament space,
which has limited capacity to absorb or distribute fluid, will
result in high fluid pressure. In the latter case, the maximum
fluid pressure will ultimately be limited by the pressure (force)
attainable with the injection device. The present device provides a
slow, controlled, injection which tends to reduce patient
discomfort by reducing interstitial pressure (relative to
traditional, manual, methods).
[0005] Dental anesthesia is known to be delivered from pre-filled,
single use, carpules with a glass barrel and rubber-like plunger
(by "rubber-like" it means actual rubber or some other material
having physical properties similar to rubber). There are a variety
of hand-operated dental syringes which hold these anesthesia
carpules and drive the rubber plunger forward. In most clinical
procedures, the dentist performs an aspiration to determine if a
blood vessel has been entered, before injecting the anesthetic.
(Injecting the anesthetic in the bloodstream is potentially
hazardous.) Aspiration is accomplished by briefly retracting the
carpule plunger to create a slight vacuum. There are a variety of
means to retract the plunger, including the following: various
mechanical hooks, harpoons, barbs, and corkscrews which embed in
and grip the carpule plunger; a gripping member on the tip of the
syringe plunger penetrates and grips the carpule's elastomeric
seal. The gripping members are variously hooks, pointed needles,
barbed needles, or corkscrews. This method is common in
thumb-actuated syringes. One shortcoming of this method is that the
carpule must be rapidly jammed onto the gripping member in order to
embed it into the carpule seal without excess expulsion of
anesthetic fluid. Another drawback is that various designs of
gripping members either pull out of the carpule seal prematurely,
or are not easily removed after injection is completed.
[0006] Sealed syringe plungers which create a vacuum behind the
carpule plunger are known. A secondary seal on the syringe plunger
creates a slight vacuum behind the carpule seal so the carpule seal
retracts when the syringe plunger is pulled back. This method is
used in a product known as The Wand computer controlled syringe. A
drawback of this method is that the carpule seal is not
consistently retracted. Another drawback is that the syringe
plunger seal must be periodically cleaned, lubricated, or
replaced.
[0007] Methods which create a vacuum in the carpule by distorting
its needle septum are known. In this method, the syringe induces
relative motion between the carpule and it's seal, creating the
slight vacuum. In a variation of this method, the syringe induces a
deflection in the carpule's septum, creating a slight vacuum in the
carpule.
[0008] It has been found in laboratory tests, that none of these
method work reliably, failing in one or more of the following ways:
did not penetrate certain brands of carpules with high durometer
rubber plungers; requiring excessive user effort or skill; pulling
out of the carpule plunger and therefore failing to create an
aspiration vacuum; and/or, becoming loaded with the silicone
lubricant used on these carpule plungers, and then failing to grip
the plunger.
[0009] A harpoon design which solves these problems is
desirable.
[0010] Further, previous dental anesthesia syringes have had
several problems in their operation: only a single injection rate
for all procedures; only crude feedback on the amount of anesthetic
injected; no feedback for the elapsed time of injection; does not
allow the practitioner to speed-up the injection rate.
[0011] One device, described in U.S. Pat. No. 5,690,618, addressed
some of these issues, but exhibited other problems: very complex to
use, requiring the clinician to program various rates and times for
each injection; and, no feedback for the elapsed time or cumulative
volume of injection.
[0012] This present invention is indicated for all dental
anesthesia procedures, including, but not limited to, procedures
such as: periodontal ligament (PDL); intraseptal; posterior
superior alveolar block (PSA); middle superior alveolar block
(MSA); anterior superior alveolar block (infraorbital); maxillary
block; greater palatine block (palaral); nasopalatine block;
supraperiosteal (infiltration); inferior alveolar block (mandibular
block); buccal block; mandibular block (Gow- Gates); intraseptal;
intrapulpal; AMSA; P-AMSA, and the like.
DISCLOSURE OF THE INVENTION
[0013] It is therefore, an object of the present invention to
provide syringe useful in dispensing fluid materials.
[0014] It is another object of the invention to provide such a
syringe particularly suited for the dispensing of dental
materials.
[0015] It is a further object of the invention to provide such a
syringe that is computer controlled.
[0016] It is yet another object of the invention to provide such a
syringe with an improved harpoon connector between a drive shaft
and a carpule seal.
[0017] These and other objects of the invention that will become
apparent from the following discussion are carried out by the
invention as hereinafter described and claimed.
[0018] In general, an electrically controlled syringe for
dispensing a fluid material, comprises a power drive unit
electrically and operatively connected to a syringe unit via at
least one connecting conduit; said syringe unit having a releasably
connected carpule holder, said carpule holder being initially
loaded with the material to be dispensed, said carpule holder being
releasably connected at one end to said syringe unit and fluidly
connected at its other end to a dispensing needle, said carpule
holder having a rubber-like plunger seal laterally displaceable
therein between a dispensing and a retracted position, such that
when said carpule plunger seal is moved toward a dispensing
position, the material in said carpule holder is caused to flow
through said dispensing needle; a longitudinally movable, powered
drive shaft in said syringe unit and releasably connected to said
carpule plunger seal, said drive shaft having an end proximal to
and an end distal to said carpule plunger seal when said carpule
holder is in place on said syringe unit; wherein said drive shaft
is provided with a harpoon at said proximal end; said harpoon
having a swept-back, barbed point and knife edges along its length,
such that said barbed point is insertable into said rubber-like
carpule plunger seal, and is selectively prevented from being
removed by physical contact between said barbed point and said
carpule plunger seal; an electric drive motor operatively affixed
to said drive shaft, and operatively connected to said power drive
unit, such that the rate of and direction of the longitudinal
displacement of said drive shaft is selectable by electrical,
operative signals received from said power drive unit to cause said
drive motor to displace said drive shaft in a selected longitudinal
direction at a selected rate, thereby laterally displacing said
operatively connected harpoon and carpule plunger seal, said drive
motor being operable with electric power received from said power
drive unit; said harpoon being fabricated from a hard, corrosion
resistant, sterilizable material; a stripper ring positioned within
said syringe unit and proximate to said carpule plunger seal when
said carpule holder is in place upon said syringe unit, such that
when said carpule plunger seal is moved from the dispensing to the
retracted position, said stripper ring physically engages said
carpule plunger seal, preventing further retracting movement of
said carpule plunger seal and hence, allowing extraction of said
harpoon from said carpule plunger seal; said stripper ring having
an inside diameter larger than said harpoon such that said harpoon
is receivable therein; and at least one secondary injection control
mechanism located proximate to said syringe unit and distal to said
power drive unit, wherein said secondary injection control
mechanism is operatively connected to said syringe drive motor to
control the longitudinal displacement direction or rate of said
drive shaft, and hence, the injection rate of the material
dispensed from said needle.
[0019] In another embodiment of the invention, an electrically
controlled syringe for dispensing a fluid material comprises a
power drive unit electrically and operatively connected to a
syringe unit via at least one connecting conduit; said syringe unit
having a releasably connected carpule holder, said carpule holder
being initially loaded with the material to be dispensed, said
carpule holder being releasably connected at one end to said
syringe unit and fluidly connected at its other end to a dispensing
needle, said carpule holder having a rubber-like plunger seal
laterally displaceable therein between a dispensing and a retracted
position, such that when said carpule plunger seal is moved toward
a dispensing position, the material in said carpule holder is
caused to flow through said dispensing needle; a longitudinally
movable, powered drive shaft in said syringe unit and releasably
connected to said carpule plunger seal, said drive shaft having an
end proximal to and an end distal to said carpule plunger seal when
said carpule holder is in place on said syringe unit; wherein said
drive shaft is provided with a harpoon at said proximal end; said
harpoon having a swept-back, barbed point and knife edges along its
length, such that said barbed point is insertable into said
rubber-like carpule plunger seal, and is selectively prevented from
being removed by physical contact between said barbed point and
said carpule plunger seal; an electric drive motor operatively
affixed to said drive shaft, and operatively connected to said
power drive unit, such that the rate of and direction of the
longitudinal displacement of said drive shaft is selectable by
electrical, operative signals received from said power drive unit
to cause said drive motor to displace said drive shaft in a
selected longitudinal direction at a selected rate, thereby
laterally displacing said operatively connected harpoon and carpule
plunger seal, said drive motor being operable with electric power
received from said power drive unit; said harpoon being fabricated
from a hard, corrosion resistant, sterilizable material; and at
least one secondary injection control mechanism located proximate
to said syringe unit and distal to said power drive unit, wherein
said secondary injection control mechanism is operatively connected
to said syringe drive motor to control the longitudinal
displacement direction or rate of said drive shaft, and hence, the
injection rate of the material dispensed from said needle.
[0020] A computer controlled syringe for dispensing a fluid
material also comprises a power drive unit electrically and
operatively connected to a syringe unit via at least one connecting
conduit; said power drive unit including a logic control circuit;
said syringe unit having a releasably connected carpule holder,
said carpule holder being initially loaded with the material to be
dispensed, said carpule holder being releasably connected at one
end to said syringe unit and fluidly connected at its other end to
a dispensing needle, said carpule holder having a rubber-like
plunger seal laterally displaceable therein between a dispensing
and a retracted position, such that when said carpule plunger seal
is moved toward a dispensing position, the material in said carpule
holder is caused to flow through said dispensing needle; a
longitudinally movable, powered drive shaft in said syringe unit
and releasably connected to said carpule plunger seal, said drive
shaft having an end proximal to and an end distal to said carpule
plunger seal when said carpule holder is in place on said syringe
unit; wherein said drive shaft is provided with a harpoon at said
proximal end; said harpoon having a swept-back, barbed point and
knife edges along its length, such that said barbed point is
insertable into said rubber-like carpule plunger seal, and is
selectively prevented from being removed by physical contact
between said barbed point and said carpule plunger seal; an
electric drive motor operatively affixed to said drive shaft, and
operatively connected to said power drive unit, such that the rate
of and direction of the longitudinal displacement of said drive
shaft is selectable by electrical, operative signals received from
said logic control circuit of said power drive unit to cause said
drive motor to displace said drive shaft in a selected longitudinal
direction at a selected rate, thereby laterally displacing said
operatively connected harpoon and carpule plunger seal, said drive
motor being operable with electric power received from said power
drive unit; said harpoon being fabricated from a hard, corrosion
resistant, sterilizable material; and at least one secondary
injection control mechanism located proximate to said syringe unit
and distal to said power drive unit, wherein said secondary
injection control mechanism is operatively connected to said
syringe drive motor to control the longitudinal displacement
direction or rate of said drive shaft, and hence, the injection
rate of the material dispensed from said needle.
[0021] A programmable, electrically controlled syringe for
dispensing a fluid material according to the invention comprises a
power drive unit electrically and operatively connected to a
syringe unit via at least one connecting conduit; said syringe unit
having a releasably connected carpule holder, said carpule holder
being initially loaded with the material to be dispensed, said
carpule holder being releasably connected at one end to said
syringe unit and fluidly connected at its other end to a dispensing
needle, said carpule holder having a rubber-like plunger seal
laterally displaceable therein between a dispensing and a retracted
position, such that when said carpule plunger seal is moved toward
a dispensing position, the material in said carpule holder is
caused to flow through said dispensing needle; a longitudinally
movable, powered drive shaft in said syringe unit and releasably
connected to said carpule plunger seal, said drive shaft having an
end proximal to and an end distal to said carpule plunger seal when
said carpule holder is in place on said syringe unit; wherein said
drive shaft is provided with a harpoon at said proximal end; said
harpoon having a swept-back, barbed point and knife edges along its
length, such that said barbed point is insertable into said
rubber-like carpule plunger seal, and is selectively prevented from
being removed by physical contact between said barbed point and
said carpule plunger seal; an electric drive motor operatively
affixed to said drive shaft, and operatively connected to said
power drive unit, such that the rate of and direction of the
longitudinal displacement of said drive shaft is selectable by
electrical, operative signals received from said power drive unit
to cause said drive motor to displace said drive shaft in a
pre-selected longitudinal direction at a pre-selected rate, thereby
laterally displacing said operatively connected harpoon and carpule
plunger seal, said drive motor being operable with electric power
received from said power drive unit; said harpoon being fabricated
from a hard, corrosion resistant, sterilizable material; and at
least one secondary injection control mechanism located proximate
to said syringe unit and distal to said power drive unit, wherein
said secondary injection control mechanism is operatively connected
to said syringe drive motor to control the longitudinal
displacement direction or rate of said drive shaft, and hence, the
injection rate of the material dispensed from said needle.
[0022] Also according to the invention, an electrically controlled
syringe for dispensing a fluid material comprises a power drive
unit electrically and operatively connected to a syringe unit via
at least one connecting conduit; said syringe unit having a
releasably connected carpule holder, said carpule holder being
initially loaded with the material to be dispensed, said carpule
holder being releasably connected at one end to said syringe unit
and fluidly connected at its other end to a dispensing needle, said
carpule holder having a rubber-like plunger seal laterally
displaceable therein between a dispensing and a retracted position,
such that when said carpule plunger seal is moved toward a
dispensing position, the material in said carpule is caused to flow
through said dispensing needle; a longitudinally movable, powered
drive shaft in said syringe unit and releasably connected to said
carpule plunger seal, said drive shaft having an end proximal to
and an end distal to said carpule plunger seal when said carpule
holder is in place on said syringe unit; wherein said drive shaft
is provided with a harpoon at said proximal end; said harpoon
having a swept-back, barbed point and knife edges along its length,
such that said barbed point is insertable into said rubber-like
carpule plunger seal, and is selectively prevented from being
removed by physical contact between said barbed point and said
carpule plunger seal; an electric drive motor operatively affixed
to said drive shaft, and operatively connected to said power drive
unit, such that the rate of and direction of the longitudinal
displacement of said drive shaft is selectable by electrical,
operative signals received from said power drive unit to cause said
drive motor to displace said drive shaft in a selected longitudinal
direction at a selected rate, thereby laterally displacing said
operatively connected harpoon and carpule plunger seal, said drive
motor being operable with electric power received from said power
drive unit; said harpoon being fabricated from a hard, corrosion
resistant, sterilizable material; said power drive unit having
image displays to provide digital or analog indicia of system
parameters selected from the group consisting of elapsed time of
dispensing, rate of dispensing, volume of material dispensed,
dispensing or aspirating mode, or combinations thereof.
[0023] Still another embodiment of the invention comprises an
electrically controlled syringe for dispensing a fluid material
having a power drive unit electrically and operatively connected to
a syringe unit via at least one connecting conduit; said syringe
unit having a releasably connected carpule holder, said carpule
holder being initially loaded with the material to be dispensed,
said carpule holder being releasably connected at one end to said
syringe unit and threadably and fluidly connected at its other end
to a dispensing needle, said carpule holder having a rubber-like
plunger seal laterally displaceable therein between a dispensing
and a retracted position, such that when said carpule plunger seal
is moved toward a dispensing position, the material in said carpule
holder is caused to flow through said dispensing needle; a
longitudinally movable, powered drive shaft in said syringe unit
and releasably connected to said carpule plunger seal, said drive
shaft having an end proximal to and an end distal to said carpule
plunger seal when said carpule holder is in place on said syringe
unit; wherein said drive shaft is provided with a harpoon at said
proximal end; said harpoon having a swept-back, barbed point and
knife edges along its length, such that said barbed point is
insertable into said rubber-like carpule plunger seal, and is
selectively prevented from being removed by physical contact
between said barbed point and said carpule plunger seal; an
electric drive motor operatively affixed to said drive shaft, and
operatively connected to said power drive unit, such that the rate
of and direction of the longitudinal displacement of said drive
shaft is selectable by electrical, operative signals received from
said power drive unit to cause said drive motor to displace said
drive shaft in a selected longitudinal direction at a selected
rate, thereby laterally displacing said operatively connected
harpoon and carpule plunger seal, said drive motor being operable
with electric power received from said power drive unit; said
harpoon being fabricated from a hard, corrosion resistant,
sterilizable material; a stripper ring positioned within said
syringe unit and proximate to said carpule plunger seal when said
carpule holder is in place upon said syringe unit, such that when
said carpule plunger seal is moved from the dispensing to the
retracted position, said stripper ring physically engages said
carpule plunger seal, preventing further retracting movement of
said carpule plunger seal and hence, allowing extraction of said
harpoon from said carpule plunger seal; said stripper ring having
an inside diameter larger than said harpoon such that said harpoon
is receivable therein; and at least one secondary injection control
mechanism located proximate to said syringe unit and distal to said
power drive unit, wherein said secondary injection control
mechanism is operatively connected to said syringe drive motor to
control the longitudinal displacement direction or rate of said
drive shaft, and hence, the injection rate of the material
dispensed from said needle.
[0024] A system according to the invention, for administering an
anesthetic into a patient, comprises a container storing an
anesthetic; a needle; and means for delivering the anesthetic
through the needle at a first predetermined rate for a first
predetermined time and then at a second predetermined rate for a
second predetermined time.
[0025] Another system for delivering an anesthetic into a patient
according to the invention, comprises a handheld unit comprising a
needle, a cartridge of anesthetic and means for flowing the
anesthetic through the needle; and, a control unit to control
operation of the handheld unit, the control unit comprising means
for operating the means for flowing the anesthetic through the
needle to deliver the anesthetic through the needle at a first
predetermined rate for a first predetermined time and then at a
second predetermined rate for a second predetermined time, wherein
the second predetermined rate is selectable by a user. The means
for flowing the anesthetic may comprise a motor and a plunger,
wherein operation of the motor in a first direction advances the
plunger against the cartridge of anesthetic to flow anesthetic from
the cartridge through the needle and operation of the motor in a
second direction retracts the plunger from the cartridge of
anesthetic; and, the means for operating the means for flowing
further comprises a processing unit to generate control signals to
operate the motor to advance and retract the plunger.
[0026] In another embodiment of the invention, a computer program
is embodied on a computer readable medium and executable by a
microprocessor for controlling a device to deliver a local
anesthetic into a patient through a needle, the computer program
product comprises computer instructions for executing the steps of:
generating a first at least one signal to operate the device to
deliver the local anesthetic at a first predetermined rate for a
first predetermined time period; transmitting the first at least
one signal to the device to operate the device to deliver the local
anesthetic at a first predetermined rate for a first predetermined
time period; generating a second at least one signal to operate the
device to deliver the local anesthetic at a second predetermined
rate for a second predetermined time period; and, transmitting the
second at least one signal to the device for the device to operate
at the second predetermined rate for the second predetermined time
immediately upon completion of the first predetermined time period.
In one embodiment, the second predetermined rate is in the range of
0.005-0.02 cc/sec. In another embodiment, the second predetermined
time is in the range of 30-240 seconds. In a preferred embodiment,
the step of generating a second at least one signal further
comprises the steps of receiving a user signal corresponding to an
injection type selected by a user; determining a delivery rate and
delivery time based on the injection type received in the user
signal; and, generating the second at least one signal to operate
the device to deliver the local anesthetic at the delivery rate for
the delivery time based on the selected injection type. The
computer program may include instructions for executing the steps
of calculating a rate of delivery of the local anesthetic through
the needle, and displaying the calculated rate of delivery of the
local anesthetic. The program may also include instructions for
calculating an elapsed time of delivery of the local anesthetic
through the needle and displaying the elapsed time of delivery of
the local anesthetic; or, calculating a volume of the local
anesthetic delivered through the needle and displaying the volume
of delivered local anesthetic. The computer program may also
include instructions for receiving a user signal corresponding to a
load command selected by a user; generating a third at least one
signal to operate the device to position components of the device
to receive a cartridge storing the local anesthetic; and,
transmitting the third at least one signal to the device for
loading the local anesthetic cartridge in the device. It may also
include instructions for receiving a user signal corresponding to
an unload command selected by a user; generating a third at least
one signal to operate the device to position components of the
device to remove a cartridge storing the local anesthetic; and,
transmitting the third at least one signal to the device for
unloading the local anesthetic cartridge from the device. In
another embodiment, the program includes instructions for receiving
a user signal corresponding to a double command selected by a user;
generating a third at least one signal to operate the device to
increase the rate of delivery of the local anesthetic to twice the
rate of delivery being provided by the device; and, transmitting
the third at least one signal to the device for increasing the rate
of delivery of the local anesthetic by the device.
[0027] There is also provided according to the present invention, a
method of delivering a local anesthetic to a patient. The method
comprises the steps of selecting a preprogrammed injection type for
delivering a local anesthetic to a patient; delivering the local
anesthetic to a patient with a motor driven syringe at a first
predetermined rate for a first predetermined time period based on
the selected injection type; then delivering the local anesthetic
to a patient with the motor driven syringe at a second
predetermined rate for a second predetermined time period based on
the selected injection type. In one embodiment, the step of
delivering the local anesthetic to a patient with a motor driven
syringe at a first predetermined rate further comprises generating
in a control unit a first at least one signal to operate the motor
driven syringe to deliver the local anesthetic to a patient at a
first predetermined rate for a first predetermined time period;
and, transmitting from the control unit to the motor driven syringe
the first at least one signal to operate the motor driven syringe
to deliver the local anesthetic at a first predetermined rate for a
first predetermined time period. The step of delivering the local
anesthetic to a patient with the motor driven syringe at a second
predetermined rate may further comprise generating in the control
unit a second at least one signal to operate the motor driven
syringe to deliver the local anesthetic at a second predetermined
rate for a second predetermined time period; and, transmitting from
the control unit to the motor driven syringe the second at least
one signal for the motor driven syringe to operate at the second
predetermined rate for the second predetermined time immediately
upon completion of the first predetermined time period.
BRIEF DISCUSSION OF THE DRAWINGS
[0028] FIG. 1 is a perspective view of the harpoon portion of a
dental syringe, according to the invention.
[0029] FIG. 2 is a view of the opposite side of the harpoon as
shown in FIG. 1.
[0030] FIG. 3 is a side elevational view of the harpoon shown in
FIG. 1.
[0031] FIG. 4 is a perspective view of a dental syringe according
to the present invention.
[0032] FIG. 5 is a lengthwise cross-sectional view of the syringe
of FIG. 4.
[0033] FIG. 6 is a cross-sectional, perspective view of one portion
of the syringe of FIG. 5.
[0034] FIG. 7 is a closeup view of one portion of the cross-section
of FIG. 5, showing the harpoon of FIGS. 1-3 in place in the
syringe.
[0035] FIG. 8 is a partially schematic representation of a control
panel for the computer-controlled syringe according to the present
invention.
[0036] FIG. 9 is a perspective view of a carpule holder useful with
the syringe of FIG. 4.
[0037] FIG. 10 is a side elevational view of the carpule holder of
FIG. 9.
[0038] FIG. 11 is a sectional view of the carpule holder of FIG. 10
taken along lines 11-11 thereof.
[0039] FIG. 12 is a closeup sectional view of one portion of the
carpule holder of FIG. 10, taken along lines 12-12 thereof.
[0040] FIG. 13 is an end elevational view of the carpule holder of
FIG. 10.
[0041] FIG. 14 is a sectional, partially broken away view of
carpule of FIG. 14, taken along lines 14-14 thereof.
[0042] FIG. 15 is a perspective view of the syringe of FIG. 4
without the carpule holder in place and showing the carpule
holder-connector end.
[0043] FIG. 16 is a closeup view of one end of the syringe of FIG.
15.
[0044] FIG. 17 is a flowchart of one embodiment of the programming
logic employed with the computer controlled device of FIG. 1.
PREFERRED EMBODIMENTS FOR CARRYING OUT THE INVENTION
[0045] An exemplary computer controlled syringe, embodying the
concepts of the present invention, is generally shown by the number
10 on the attached drawings. Syringe 10 has a dispensing tip 11
fluidly affixed to a carpule holder 12, which carpule holder 12 is
releasably affixed or connected to a syringe power unit 13.
[0046] Carpule holder 12 is initially (that is, prior to
dispensing) loaded with the material to be dispensed (not shown) by
any conventional means, such as a conventional carpule or the like.
Any carpule capable of being dispensed by the action of a
physically engaging plunger (to be discussed below) is within the
scope of the invention. Carpule holder 12 may be affixed to syringe
10 by any conventional means, including for example, bayonet
connector 50 at one end of carpule holder 12. At it other end,
carpule holder 12 is preferably provided with means to affix or
removably affix the dispensing tip 11. In the case of the use of
syringe 10 to dispense a dental anesthetic or the like, dispensing
tip 11 is a hypodermic needle, which is affixed by conventional
means, such as friction, screw threads or the like, to carpule
holder 12. Preferably, dispensing tip 11 is fluidly affixed to
carpule holder 12, so as to fluidly communicate with the interior
thereof, or whatever carpule or the like is employed.
[0047] Carpule holder 12 is provided with a carpule plunger seal
32, which is preferably rubber-like in manufacture, for reasons to
be discussed. Carpule plunger seal 32 is preferably laterally
displaceable within carpule holder 12 to thereby provide for
dispensing of material from carpule holder 12 or aspiration of
external material through dispensing tip 11. Thus, preferably,
carpule plunger seal 32 is selectively, laterally displaceable
between a dispensing and a retracting movement. When carpule
plunger seal 32 is caused to move toward affixed dispensing tip 11,
material in carpule holder 12 is caused to flow toward dispensing
tip 11, and when expressed therethrough, is said to have dispensed
the material.
[0048] Syringe power unit 13 of syringe 10 is preferably provided
with an electric drive motor 60, which is employed to laterally
displace a drive shaft 61. Motor 60 may be of any conventional
design, but is preferably an electrically powered stepper motor
with integral internal rotating nut that drives a lead-screw to
provide open-loop linear motion. Such motors are commercially
available for example, from Haydon Switch and Signal, as well as
others. Further, motor 60 should be capable of being controlled as
to start and stop of motion, as well as amount of and speed of the
lateral displacement of the drive shaft 61, by signals received
from an operator, and more preferably received via conduit 41 from
power drive unit 40. Motor 60 may also be powered by electricity
received through conduit 41 or by any other conventional means,
such as batteries located in syringe 10 (not shown). Drive shaft 61
is operatively and releasably connected to carpule plunger seal 32,
by any means but preferably by the means described herein.
[0049] Drive shaft 61 preferably has an end proximal to and an end
distal to carpule holder 12 when carpule holder 12 is connected to
syringe 10. In order to effect the connection between drive shaft
61 and carpule plunger seal 32, it is preferred to employ an
inventive harpoon 20 that will be hereinafter described.
[0050] Syringe 10 is operatively and electrically connected to a
power drive or base unit 40 (FIG. 8) via a connecting conduit 41
(FIGS. 5). Power drive unit 40 via conduit 41 provides electrical
signal to syringe 10 to control the operation thereof, and
preferably includes a logic control circuit (not shown) of any
suitable sort to provide such selected or predetermined control
signals, as exemplified by the flowchart shown in FIG. 17. For
example, power drive unit 40 may be used to control the flow rate,
flow duration, start, stop, elapsed time, volume of dispensed
material, direction of material flow, connection to a carpule
(known as loading) or disconnecting therefrom (unloading) or the
like. The mechanism of such controls will be described below in
greater detail. Control signals from power drive unit 40 may be
digital or analog, and may be displayed by any suitable means,
including using digital readouts 42 (rate of dispensing), 43,
(volume of material dispensed), 44 (time of dispensing), or any
other desired parameter without limitation. Control mechanisms
include buttons 45 for controlling dispensing conditions or
parameters, or the like. Power drive unit 40 may be preset for
automatic control of dispensing parameters, or such parameters may
be individually controlled. As an example of a preset parameter, a
button 45 may provide for a doubling of the rate of dispensing of
material. By using a logic control circuit or computer, the number
of, type of, rate of or the like of all syringe parameters can be
preselected, and hence, the device is programmable.
[0051] Conduit 41 may also be used to provide electrical power to
syringe 10 for purposes to be more fully explained in the following
discussion. If required, multiple conduits (not shown) similar to
conduit 41 or of some other conventional design, may be
employed.
[0052] Syringe 10 will be exemplified herein with respect to the
dispensing of a dental anesthetic material, it being understood
that the invention has application to many materials including the
dispensing of medical, industrial or other dental materials.
[0053] The general operation of syringe 10 in delivering
anesthetics to a patient, is well known in the art, except as
otherwise described, noted and claimed. For example, a power driven
syringe is shown in U.S. Pat. No. 5,690,618, which is hereby
incorporated by reference for such disclosure.
[0054] As stated above, an inventive harpoon 20 is provided
according to the present invention. Harpoon 20 would typically and
preferably be made of stainless steel or other hard, corrosion
resistant, sterilizable, material. Harpoon 20 has a unique barb 21
geometry and hardened, knife-like, edges 22 located along its
length, with the following advantages: the thin configuration,
sharp point, and hard knife edges 22 of the harpoon uniquely allow
consistent penetration into all types of elastomer carpule seals,
such as carpule plunger seal end 23, even those of hard rubber,
with lower force than other gripper types. Thus, it does not
require the operator to jam the carpule into the syringe. The
swept-back barbs 21 allow the harpoon to consistently remain in the
carpule plunger, up to five times more effectively than other
gripper types. Thus, aspiration is consistent. This design is
easily fabricated at low cost, and has a long life (number of
insertions into rubber). The design reduces or eliminates the
drawbacks of the vacuum type.
[0055] Because harpoon 20 is affixed to carpule plunger seal 32 and
to drive shaft 61, lateral displacement of drive shaft 61 also
causes lateral displacement of harpoon 20 and hence, also of
affixed carpule plunger seal 32.
[0056] Another inventive feature of the invention is the
incorporation of a stripper ring 30 in the syringe device 10. This
ring has an inside diameter (ID) slightly larger than the harpoon
20 but smaller than a standard carpule plunger seal 23. Thus, when
the syringe plunger seal 32 is fully retracted, the harpoon 20 is
pulled out of the carpule seal 23 while the carpule seal 23 remains
within the carpule holder 12, by physical contact between stripper
ring 30 and carpule plunger seal 32, thereby preventing further
movement of carpule plunger seal 32. Continued retracting movement
of drive shaft 61 and affixed harpoon 20 past the point physical
contact between stripper ring 30 and carpule plunger seal 32 will
cause harpoon 20 to be physically disengaged from carpule plunger
seal 32. By being a ring of proper dimension, harpoon 20 and drive
shaft 61 maybe received within stripper ring 30.
[0057] Harpoon 20 has the following advantages: it readily
penetrates the carpule plunger seal 32 with only moderate force,
even plungers made of high durometer rubber; it does not pull out
of the carpule plunger seal 32, even in repeated aspirations;
nonetheless, it can be readily stripped from the carpule plunger
seal 32 with proper syringe design, using stripper ring 30; its
shape is suited to low-cost manufacturing.
[0058] As discussed above, it is preferred to control dispensing
parameters of syringe 10 by control signals or commands received
from power drive unit 40. It is also an advantage of the present
invention, that an operator can control some or all such parameters
by use of a secondary injection control mechanism 70 (FIG. 5)
located proximate to syringe 10 and distal to power drive unit 41.
Secondary injection control mechanism 70 is operatively connected
to said drive motor 60, such as by connector 71, to control the
longitudinal displacement direction or rate of drive shaft 61, by
command signals that start, stop, adjust speed, torque, or the like
of motor 60, and hence, the injection rate of the material
dispensed from dispensing tip 11. Secondary injection control
mechanism 70 may be of any design such as a switchboard 72, button
73 design as depicted in the drawings.
[0059] According to one embodiment of the invention, a limit switch
of any suitable design, including those of analog or digital design
is employed. For example, limit switch 80a (FIG. 5) may be
operatively connected to drive motor 60. A limit (or "home") switch
80a is actuated when the leadscrew or drive shaft 61 is in the
fully retracted position. Preferably, the unit 10 automatically
retracts the drive shaft 61 to home position upon power up. All
drive shaft 61 motion is then referenced by counting motor steps
from this position. Previous syringe devices did not have a limit
switch, but relied on running the motor in reverse for a fixed time
at power up to ensure it would reach home position.
[0060] Certain injection modes, such as PDL injections, require
increased injection pressure. When the PDL injection type is
selected, motor voltage is preferably increased to 10 volts during
the injection Slow Phase and Regular Phase forward motion. Other
injection types and other plunger motions are at normal motor
voltage of 5 volts. To prevent motor overheating, voltage is
increased for only 10% duty cycle.
[0061] The syringe 10 according to the present invention also
divides the delivery of anesthesia into two phases. According to
the method of the present invention, during the first 10 seconds of
the injection, anesthetic is delivered at an extremely slow rate to
maximize patient comfort. The injection rate then automatically
increases to the preprogrammed rate associated with the injection
type you have selected. The following steps refer to the control
panel of FIG. 8.
[0062] A. Select your injection by depressing the appropriate
button under Injection Technique. The injection rate will be
displayed in the box title Rate cc/sec.
[0063] B. Once the injection technique is selected, you are ready
to proceed.
[0064] C. Aspiration is achieved by pressing and releasing the
middle button on the handpiece, once.
[0065] D. After aspiration, press an release the front start/stop
button on the handpiece to initiate the injection.
[0066] E. At any time during the injection you may stop by simply
pressing the front start/stop button on the handpiece to stop the
program.
[0067] F. You can double the rate of injection at any time by
pressing the back button on the handpiece or the double rate button
on the base unit. To turn this feature off, simply push the Double
button again on either the handpiece or the control box.
[0068] G. When you are through with the injection, press and
release the front start/stop button once to stop the program.
[0069] H. If you inject into a new site, change your injection
technique setting if necessary, follow steps A-D and the program
will automatically start over.
[0070] I. When finished, re-sheath the needle and set the handpiece
in the holder."
[0071] Other physical embodiments utilizing the same simplified
control scheme. For example, a unitary battery operated
handpiece.
[0072] It will be appreciated that the syringe according to the
present invention is simple to use. Control choices are directly
related to known clinical practice rather than arcane rates and
times. It provides clinically useful display information.
[0073] As shown in FIGS. 5 and 9, carpule holder 12 is provided
with a discharge end 80 and a connector end 81. Connector end 81 is
used to removably affix carpule holder 12 to syringe 10. Connector
end 81 is provided with wedge lugs 82 (FIGS. 9-11), which
physically engage circumferential lips 83 carried by syringe 10
(FIGS. 13 and 15). The physical engagement of lugs 82 with lips 83
causes lips 83 to removably hold carpule holder 12 thereto, in a
bayonet-like manner.
[0074] An exemplary computer controlled syringe, embodying the
concepts of the present invention, is generally shown by the number
10 on the attached drawings. Syringe 10 has a needle 11 affixed to
a carpule 12, which carpule 12 is affixed to a power drive unit 13
(FIG. 5). The general operation of syringe 10 in delivering
anesthetics to a patient, is well known in the art, except as
otherwise described, noted and claimed. For example, a power driven
syringe is shown in U.S. Pat. No. 5,690,618, which was herein
incorporated by reference for such disclosure.
[0075] As described herein, the present inventive syringe is a
partially automated, mechanized system intended for injection of
anesthetics in dental procedures. The intended benefit of this
automation is precise control of anesthetic injections, resulting
in less undesired numbing of the patient's facial muscles, reduced
patient pain, easier injection into hard tissue areas, and improved
practitioner comfort.
[0076] The system is comprised of an electronic control unit, a
handheld motor driven syringe (the "handpiece"), and a single-use
cartridge holder. All operating displays and the majority of the
operator controls are located on the front panel of the control
unit. The control unit also houses a microprocessor and motor drive
circuits. The handpiece houses a stepper motor and lead screw which
drive the syringe plunger. The single-use cartridge holder encloses
standard 1.8 cc dental anesthetic cartridges and mates with
standard dental anesthetic needles.
[0077] In preparation for use, the dental practitioner assembles a
needle to the cartridge holder, places a standard 1.8 cc cartridge
of anesthetic in a disposable plastic cartridge holder, and
attaches the cartridge holder to the handpiece. The practitioner
then sets operating parameters on the control unit. After the
practitioner inserts a standard dental needle into the patient,
injection of anesthetic is regulated by a combination of controller
programming and practitioner actuation of buttons on the handpiece
or controller.
[0078] The inventive syringe according to the invention uses a
two-stage injection to provide you an easier means of delivering an
effective pain controlled injection with as minimal post-op
discomfort as possible. The following describes inventive method
steps of using the present syringe. Where appropriate, reference is
made to the drawings, it being understood that the structure
described is that as was above discussed. Structure not shown in
the drawings may be alluded to, in which case it is understood that
the same is not shown.
Powering Up
[0079] 1. Plug the AC power cord (not shown) of the external power
supply (if employed, not shown) into a grounded electrical outlet
(not shown) of the correct voltage and current rating. Plug the low
voltage cable from the power supply into the control unit 40.
[0080] 2. Turn the control unit 40 on using the power switch on the
side. The Power light will come on.
Loading the Carpule
[0081] 1. Place dental needle 11 onto the cartridge holder 12.
[0082] 2. Load an anesthetic cartridge into the cartridge holder
12, pushing it forward so the butt end of the needle punctures the
rubber diaphragm of the cartridge, in an otherwise conventional
manner.
[0083] 3. Press the Load button 45 once to advance the plunger and
harpoon.
[0084] 4. Insert the loaded plastic cartridge holder 12 into the
handpiece 10, embedding the plunger harpoon 20 into the cartridge
plunger or seal 32. Twist the cartridge holder 12 to lock it into
the handpiece 10, thereby causing the lugs 82 and lips 83 to
removably and physically engage, securing cartridge or carpule
holder 12 to handpiece 10 in a bayonet-like manner.
Selecting the Injection Program
[0085] The inventive syringe according to the invention divides the
delivery of anesthesia into two phases. During the first 10 seconds
of the injection, anesthetic is delivered at an extremely slow rate
to maximize patient comfort. The injection rate then automatically
increases to the preprogrammed rate associated with the injection
type you have selected.
[0086] 1. Select you injection type by depressing the appropriate
button. The injection rate will be shown in the Rate (cc/sec)
display 42 on the control unit 40.
Using the Handpiece
[0087] 1. Once the injection technique is selected, the device 10
is ready to conduct an injection.
[0088] 2. Aspiration is achieved by pressing the releasing the
Aspirate (middle) button 73 on the handpiece 10.
[0089] 3. After aspiration, press and release the front Start/Stop
(forward) button 74 on the handpiece 10 to initiate the
injection.
[0090] 4. At any time during the injection the operator may stop by
simply pressing the front Start/Stop button 74 on the handpiece 10
to stop the program.
[0091] 5. The operator can double the rate of injection during the
injection sequenced by pressing the Double (rear) button 75 on the
handpiece 10 or the Double button 76 on the control unit 40.
[0092] 6. When the injection is complete, the operator will press
and release the Start/Stop button 74 on the handpiece 10 to stop
the program.
[0093] 7. If another injection is required, steps 2-4 are followed
and the program will automatically start over.
Removing the Carpule
[0094] To remove the cartridge and holder, a user will press the
Unload button 45 on the control unit 40 to fully retract the
plunger 23. This will pull the harpoon 20 from the cartridge 32.
The user will then untwist and remove the loaded cartridge holder
12 (with needle 11 attached) from the handpiece, by disengaging
lugs 82 from lips 83.
Pre-Programmed Injection Rates
[0095] The following table list exemplary pre-programmed injection
rates for different dental injection procedures. TABLE-US-00001
RATE TYPICAL TYPICAL INJECTION TYPE (CC/SEC) VOLUME TIME Block .020
1.8 cc 1 min 30 sec Infiltration .017 1.4 cc 1 min 20 sec PDL .007
.2 cc per tooth root 30 sec AMSA/P-ASA .008 .6 cc 4 min Lingual
Infiltration .010 1.4 cc 2 min 20 sec
General Operating Technique
[0096] The syringe according to the invention allows the delivery
of a slow drip of anesthetic that, if not impossible, is very
difficult to accomplish with manual, thumb controlled syringes that
have been in use for over on hundred years. The syringe according
to the invention, with a computer controlled motor, delivers the
anesthetic of choice at a programmable constant pressure and
volume. Studies show that a slow controlled release of the
anesthetic solution keeps the anesthetic in the target zone and
does not force the fluid into the surrounding tissue where its
effect is drastically reduced. This also minimized the pain
associated with injection by minimizing soft tissue trauma that
results when a sudden bonus or solution creates undue pressure or
tears the tissue. The resulting ease of administration and
reduction of pain reduces the patient stress associated with
injections for dental anesthesia.
[0097] It should therefore be apparent that the dental syringe as
described herein carries out the object of the invention and
otherwise provides an advance and contribution to the art. The
invention has been exemplified with respect to drawings and
description, without an attempt to provide a depiction or
description of every embodiment of the event of device or method.
Those skilled in the art will readily understand that various
sizes, components and method steps can be employed and still fall
within the scope of the present invention.
* * * * *