Medical syringe abstract
A rotational pressure drive for filling a medical syringe with
a fluid and obtaining, maintaining, and releasing a desired fluid
pressure within the syringe. The commercially available medical
syringe includes a barrel with a plunger extending therein. Extending
laterally and radially about the proximal end of the syringe barrel
are several flanges. The rotational pressure drive comprises a hollow
cylindrical chamber with a partially closed, proximal end with an
opening therethrough. The drive further includes an axial extension
member extending through the opening in the partially closed end
for engaging and urging the proximal end of the syringe plunger
toward the partially closed, proximal end. The drive, in another
aspect, includes a syringe plunger having a distal and a proximal
portion. The distal portion is inserted into the syringe barrel
with the proximal portion extending through the opening of the partially
closed, proximal portion of the drive. Positioned circumferentially
and longitudinally along the chamber are pluralities of internal
threads with individual starts for engaging the radially extending
flanges of the syringe barrel. The plunger or axial extension member
of the drive is pulled toward the partially closed, proximal end
of the drive to fill the syringe with fluid. The flanges of the
syringe barrel are rotationally engaged with the starts of the internal
thread pluralities for advancement into the passageway of the drive.
As the hollow chamber of the pressure drive is rotated with respect
to the syringe barrel, the plunger is pushed into the syringe barrel
to obtain and maintain a desired fluid pressure therein.
Medical syringe claims
What is claimed is:
1. A rotational pressure drive f or a syringe having a barrel,
a plunger positioned through a proximal end of said barrel, and
first and second flanges extending radially and laterally from said
proximal end of said barrel, comprising:
an elongated member having a partially closed end including an
opening therein, an open end for reception of said plunger, and
a passageway extending longitudinally between said open and partially
closed ends for passage of said plunger therethrough;
axial extension means moveable through said opening of said partially
closed end for pulling said plunger through said passageway toward
said partially closed end; and
first and second pluralities of internal threads extending radially
into and longitudinally along said passageway forming means for
engaging said first and second flanges, respectively.
2. The drive of claim 1 wherein the internal threads of said first
and second pluralities are positioned alternatingly between each
other.
3. The drive of claim 2 wherein said first and second pluralities
of internal threads include respective first and second starts positioned
opposite each other about said open end.
4. The drive of claim 1 wherein said first and second pluralities
of internal threads comprise respectively a first and a second continuous
helix of which the internal threads are positioned alternatingly
between each other.
5. The drive of claim 1 wherein said passageway includes a major
diameter and a minor diameter bounding said first and second pluralities
of internal threads.
6. The drive of claim 5 wherein each thread of said first plurality
includes a first flank surface having a first predetermined flank
angle and wherein each thread of said second plurality includes
a second flank surface having a second predetermined flank angle.
7. The drive of claim 6 wherein each thread of said first plurality
includes a first crest having a first predetermined thickness and
wherein each thread of said second plurality includes a second crest
having a second predetermined thickness.
8. The drive of claim 7 wherein adjacent threads of said first
and second pluralities include a root therebetween having a predetermined
width.
9. The drive of claim 8 wherein each thread of said first plurality
has a first predetermined height.
10. The drive of claim 9 wherein each thread of said second plurality
has a second predetermined height.
11. The drive of claim 1 further comprising a plurality of reinforcements
extending longitudinally about an outer surface of said drive.
12. A method of controlling the pressure in a syringe with said
drive of claim 1 said syringe having a barrel, a plunger positioned
through a proximal end of said barrel, and first and second flanges
extending radially and laterally from said proximal end of said
barrel, said method comprising the steps of:
engaging said plunger with said axial extension means;
engaging said first and second flanges with said first and second
pluralities of internal threads, respectively;
pulling said plunger toward said partially closed and with said
axial extension means; and
rotating said elongated member with respect to said syringe to
engage said plunger with said partially closed end of said elongated
member.
13. The method of claim 12 wherein said pulling includes filling
said barrel with a fluid.
14. A rotational pressure drive for a syringe having a barrel and
first and second flanges extending radially and laterally from a
proximal end of said barrel, comprising:
a plunger having a distal portion, a proximal portion, and a radial
projection extending laterally therefrom between said distal and
proximal portions;
an elongated member having a partially closed end including an
opening therein for extension of said distal portion of said plunger
therethrough and forming means for engaging said radial projection
of said plunger, an open end for reception of said plunger, and
a passageway extending longitudinally between said open and partially
closed ends for passage of said plunger therethrough; and
a plurality of internal threads having first and second starts
forming means for engaging respectively said first and second flanges.
15. The drive of claim 14 wherein each thread of said plurality
has a predetermined height, a crest having a predetermined thickness,
and a root having a predetermined width.
16. The drive of claim 14 wherein each thread of said plurality
further includes a flank surface having a predetermined flank angle.
17. A method of controlling the pressure in a syringe with said
drive of claim 14 said syringe having a barrel and first and second
flanges extending radially and laterally from a proximal end of
said barrel, said method comprising the steps of:
inserting said distal portion of said plunger into said barrel
of said syringe;
engaging said first and second flanges with said first and second
pluralities of internal threads, respectively;
pulling said proximal portion of said plunger through said opening
of said partially closed end of said elongated member; and
rotating said elongated member with respect to said syringe to
engage said radial projection of said plunger with said partially
closed end of said elongated member.
18. The method of claim 17 wherein the step of pulling includes
filling said barrel with a fluid.
19. The method of claim 17 wherein the step of rotating said elongated
member includes threading said flanges into said passageway of said
drive.
20. A rotational pressure drive and syringe, comprising:
a barrel having a proximal end and first and second flanges extending
radially and laterally from said proximal end of said barrel,
a plunger having a distal portion positioned in said barrel, a
proximal portion, and a radial projection extending laterally therefrom
between said distal and proximal portions, said proximal portion
having an end cap at a proximal end thereof;
an elongated member having a partially closed end including an
opening for extension of said proximal portion therethrough and
forming means f or engaging said radial projection of said plunger
between said distal and proximal portions, an open end for reception
of said plunger, and a passageway extending longitudinally between
said open and partially closed ends for passage of said plunger
therethrough; and
first and second pluralities of alternatingly positioned internal
threads extending radially into and longitudinally along said passageway
engaging said first and second flanges, respectively, and including
respective first and second starts positioned opposite each other
about said open end, each thread of said first plurality including
a first flank surface having a first predetermined flank angle,
a first crest having a first predetermined thickness, and a first
predetermined height, each thread of said second plurality including
a second flank surface having a second predetermined flank angle,
a second crest having a second predetermined thickness, and a second
predetermined height, adjacent threads of said first and second
pluralities including a root therebetween having a predetermined
width;
a plurality of reinforcements extending longitudinally about an
outer surface of said drive; and
first and second expansion pins extending through said elongated
member near said open end and into said passageway.
Medical syringe description
TECHNICAL FIELD
This invention relates generally to medical devices for obtaining,
maintaining, and releasing fluid pressures in a syringe and, in
particular, to a device for threadably engaging the external flanges
of a syringe for obtaining high fluid pressures in the syringe chamber.
BACKGROUND OF THE INVENTION
High fluid pressures are required for the inflation of balloons
used in medical procedures such as angioplasty and radial dilation
of the urethra. The balloons are typically inflated for an extended
period of time using a syringe filled with fluid. However, maintaining
high fluid pressures for an extended period of time is difficult
by simply applying manual force to a commercially available syringe.
One approach to this problem is to use a custom-made or modified
syringe. All of these syringes commonly include an outer, internally
threaded member and an inner, externally threaded member f or rotational
advancement of the plunger in a syringe barrel.
A disadvantage of each of these custom-made or modified syringes
is that they are relatively expensive to manufacture in comparison
to standard, commercially available syringes. Another disadvantage
is that these syringes are more complicated to use than a standard
syringe. Therefore, the physician has to become skilled at operating
the device. The physician's familiarity with the device is also
critical for maintaining or releasing pressure when a threshold
is reached. A timely release prevents bursting the balloon or overdilating
tissue. Yet another disadvantage is that these custom-made syringes
are fitted with pressure gauges or indicator rods that require visual
monitoring by the physician during use. The physician must actuate
the modified syringe while watching a pressure indicator for a threshold
pressure to be obtained. When the threshold is obtained, these custom-made
syringes are manually operated for permitting fluid to exit the
syringe chamber, thereby decreasing the fluid pressure therein.
Another prior art device utilizes an internally threaded outer
sleeve that fixedly engages the radial projections at the proximal
end of a standard syringe barrel. The device includes an externally
threaded plunger that attaches to the proximal end of a standard
syringe plunger for longitudinal movement of the syringe plunger
with respect to the pair of radial projections at the proximal barrel
end. A problem with this device is that it is expensive to manufacture.
From a user's perspective, the device is large, heavy, and cumbersome,
and therefore difficult and inconvenient to use.
Another disadvantage of these prior art devices is that the plunger
of the syringe must be disengaged from the device to fill the syringe
barrel. Alternatively, these threaded devices must be rotated to
withdraw the plunger from the distal end of the barrel to fill the
syringe with fluid. This is particularly annoying and time consuming
when the technician or physician has initially engaged the pressure
device with the syringe and forgot to initiate filling of the syringe
barrel with fluid.
SUMMARY OF THE INVENTION
The foregoing problems are solved and a technical advance is achieved
in an illustrative rotational pressure drive for engaging a standard,
commercially available medical syringe and obtaining, maintaining,
and releasing a desired fluid pressure therein. The drive comprises
an elongated member such as a hollow cylindrical chamber having
a passageway extending longitudinally between a closed end for engaging
the proximal end of the syringe plunger and an open end for receiving
the plunger and extending it through the passageway to the closed
end. The drive further includes first and second pluralities of
internal threads extending radially into and longitudinally along
the passageway for engaging the flanges extending radially and laterally
from the proximal end of the syringe barrel. Use of the pressure
drive involves fully extending the plunger proximally from the syringe
barrel and inserting the extended plunger into the open end of the
drive, through the passageway, and to the closed end. The syringe
barrel flanges engage the individual starts of the first and second
pluralities of internal threads. The drive is then advantageously
rotated with respect to the syringe barrel to thread the flanges
into the passageway of the drive and to push the plunger into the
syringe barrel. As the plunger is pushed into the syringe barrel,
the fluid pressure within the barrel is increased. Any desired pressure
may be maintained in the barrel depending on how far the flanges
of the syringe are threaded into the passageway of the drive. A
pressure limiting assembly is attached to the distal end of the
syringe barrel, which releases fluid from the syringe when a threshold
pressure is obtained.
A departure in the art is that the internal threads of the pluralities
are a modified form of an Acme thread with multiple starts. The
crest and root of an Acme thread are typically of the same width
or thickness, with each thread having a flank surface angle of approximately
14.5 degrees. The threads of the present invention have a crest
thickness that is different from the width of the thread root. Furthermore,
the pluralities of the internal threads are positioned alternatingly
between each other with each plurality having a separate start.
The first and second starts of the pluralities are opposite each
other about the open end of the passageway for engaging the diametrically
opposed flanges of a standard, commercially available syringe. The
multiple starts of the threads advantageously engage the flanges
of the syringe without distorting or deforming the flanges as they
are threaded into the passageway. The thread root width preferably
matches the width of the syringe barrel flanges with the flank surface
angle being significantly reduced from that of an Acme thread for
advantageously advancing the flanges without distortion within the
passageway of the drive. Preferably this flange surface angle is
2 degrees for minimizing distortion of the syringe barrel flanges,
reducing rotational force, and reducing thread thickness.
Each plurality of internal threads comprises a continuous helix
of which the threads of the pluralities are positioned alternatingly
between each other.
The passageway includes a minor diameter slightly larger than that
of the plunger cross-section for permitting insertion through the
passageway of the drive and a major diameter approximating the largest
radial dimension of the flanges. Thus, the major and minor diameters
bound the height of the internal threads. Advantageously, the height
of the various thread pluralities may be varied depending on the
radial dimension of each syringe flange. Furthermore, the root between
adjacent threads of the pluralities may also be varied to accommodate
various thickness flanges.
Positioned about the closed end of the elongated member and extending
radially into the passageway along the longitudinal axis thereof
is a projection for pivotally engaging the proximal end of the plunger
during rotation of the drive with respect to the syringe barrel.
This advantageously prevents distortion or deformation of the plunger
during rotation of the drive, thus preventing loss or leakage of
fluid from the syringe barrel and variations in fluid pressure levels.
The device further includes a plurality of reinforcements extending
longitudinally about the outer surface of the drive for minimizing
the bulk of the drive, while maintaining the structural integrity
and rigidity of the drive. Also included is a pressure relief assembly
including a cylinder and a spring actuated piston positioned within
the cylinder attached about the distal end of the syringe for advantageously
limiting the fluid pressure within the syringe. This prevents bursting
a treatment balloon as well as overdilating or traumatizing tissue.
In another aspect, the rotational pressure drive is considered
a plurality of internal threads having multiple first and second
starts for engagement respectively of the flanges of the syringe
barrel. Each thread of the plurality has a predetermined height,
a crest with a predetermined thickness, along with a root having
a predetermined width to match the thickness of the syringe barrel
flanges.
The foregoing problems of filling a syringe barrel with a fluid
are solved and a technical advance is achieved in an illustrative
rotational pressure drive for engaging a standard, commercially
available medical syringe and obtaining, maintaining, and releasing
a desired fluid pressure therein. The pressure drive comprises an
elongated member having a partially closed end including an opening
therein and an axial extension member movable through the opening
of the partially closed end for pulling the plunger through the
passageway of the elongated member toward the partially closed end.
Pulling the plunger through the passageway toward the partially
closed end advantageously facilitates filling the syringe barrel
with a fluid without having to operate any other portion of the
pressure device. The drive also comprises pluralities of internal
threads for engaging the radially and laterally extending flanges
of the syringe.
The method of controlling the pressure in the syringe with the
aforementioned drive includes engaging the plunger of the syringe
with the axial extension member, engaging the flanges of the syringe
with the internal threads, and pulling the plunger toward the partially
closed end of the elongated member with the axial extension member.
The method also includes rotating the elongated member of the drive
with respect to the syringe to engage the plunger with the partially
closed end of the elongated member. The step of pulling the plunger
with the axial extension member further includes advantageously
filling the barrel with a fluid without having to rotate or disengage
the internal threads of the drive with the syringe flanges.
In another aspect of the rotational pressure drive of the present
invention, the drive comprises a plunger having a distal portion,
a proximal portion, and a radial projection extending laterally
therefrom between the distal and proximal portions. The elongated
member of the drive has a partially closed end including an opening
therein for extension of the proximal portion of the plunger therethrough.
The partially closed end and opening form means for engaging the
radial projection of the plunger and controlling the pressure of
a fluid in the syringe barrel. The radial projection also permits
the syringe barrel to be readily filled with a fluid without again
having to disengage the plunger from the pressure drive or rotating
the internal threads of the drive with respect to the syringe barrel
flanges. The method of controlling the pressure in a syringe with
this aspect of the invention includes the steps of inserting the
distal portion of the plunger into the barrel of the syringe, engaging
the flanges of the barrel with the internal threads of the elongated
member, and pulling the proximal portion of the plunger through
the opening of the partially closed end of the elongated. The method
of controlling the pressure also includes rotating the drive with
respect to the syringe to engage the radial projection of the plunger
with the partially closed end of the elongated member. The step
of pulling the proximal portion of the plunger through the partially
closed end includes advantageously filling the barrel with a fluid
without having to disengage the syringe barrel with the threads
of the drive.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 depicts the rotational pressure drive and pressure relief
assembly of the present invention for a medical syringe;
FIG. 2 depicts an end view of the pressure drive of FIG. 1;
FIG. 3 depicts a cross-sectional thread profile of the pressure
drive of FIGS. 1 and 2;
FIG. 4 depicts a longitudinal, cross-sectional view of the pressure
drive of FIG. 2 along the line 4--4;
FIG. 5 depicts the pressure drive of FIG. 4 with a medical syringe
positioned therein;
FIG. 6 depicts a partial, cross-sectional view of the pressure
relief assembly of FIG. 1 attached to the distal end of a medical
syringe;
FIG. 7 depicts an enlarged partial cross-sectional view of the
piston and cylinder of the pressure relief assembly of FIG. 6;
FIG. 8 depicts a partially sectioned side view of another aspect
of the rotational pressure drive of the present invention;
FIG. 9 depicts the disassembled proximal end of the plunger of
the pressure drive of FIG. 8;
FIG. 10 depicts the assembled proximal end of the plunger of FIG.
8;
FIG. 11 depicts a partially sectioned side view of still another
aspect of the rotational pressure drive of the present invention;
FIG. 12 depicts a pictorial view of the distal end of the axial
extension member of the pressure drive of FIG. 11; and
FIG. 13 depicts the rotational pressure drive of FIG. 11 with the
axial extension member thereof engaging the proximal, partially
closed end of the drive.
DETAILED DESCRIPTION
FIG. 1 depicts rotational pressure drive 100 that is positionable
about and rotationally engageable with a standard, commercially
available, 10 cc syringe 101 for engaging and pushing syringe plunger
102 into syringe barrel 103 to control the pressure of a fluid contained
therein. The rotational pressure drive comprises elongated member
104 such as a hollow cylindrical chamber. The elongated member of
the drive has closed proximal end 105 for engaging proximal end
119 of plunger 102 open distal end 106 for receiving the plunger,
and hollow passageway 107 extending longitudinally between the open
and closed ends for passage of the plunger therethrough to the closed
end. The drive also includes a first plurality of internal threads
108 with start 109 and a second plurality of internal threads 110
with start 111 for engaging diametrically opposed syringe barrel
flanges 112 and 113. These flanges extend radially and laterally
from proximal end 114 of syringe barrel 103. Internal thread pluralities
108 and 110 extend radially into and longitudinally along the outer
circumference of hollow longitudinal passageway 107 for threading
the syringe barrel flanges longitudinally into the passageway toward
closed proximal end 105. Syringe plunger 102 includes crisscrossed
elongated members 116 and 117 with disk-like flange 118 transversely
positioned and molded with the crisscrossed plunger members at the
proximal end thereof.
Plunger 102 of the syringe is extended proximally from open proximal
end 114 of the syringe barrel and inserted into open distal end
106 of the pressure drive. The plunger is then extended through
hollow passageway 107 to engage closed proximal end 105 of the drive.
Diametrically opposed syringe barrel flanges 112 and 113 are inserted
into the open end of the drive to engage thread starts 109 and 111
respectively. The syringe barrel and drive are rotated with respect
to each other to engage and thread syringe barrel flanges 112 and
113 into internal thread pluralities 108 and 110. Rotation of the
drive with respect to the syringe barrel causes closed proximal
end 105 of the drive to engage and push proximal end 119 of the
plunger into the syringe barrel, thus increasing the pressure of
the fluid within the syringe barrel. Continued rotation of the drive
with respect to the syringe barrel further increases the pressure
of the fluid contained within the barrel.
The drive also includes pressure relief assembly 120 for limiting
the pressure of the fluid within the syringe barrel. Pressure relief
assembly 120 is connected to distal end 121 of the syringe barrel
which has a female Luer lock connector 122 positioned thereat. Pressure
relief assembly 120 is well-known and includes cylinder 123 that
communicates with a passageway extending longitudinally through
the assembly between proximally positioned, male Luer lock connector
124 and inflation tube 125 extending distally from the assembly
through end cap 126. Pressure relief assembly 120 further includes
a well-known cylindrical piston 127 that is positioned within cylinder
123 and forced therein with actuation spring 128 and end cap 129.
An o-ring seal 130 is also positioned around the piston and within
the cylinder to maintain a seal between the cylinder and piston.
Actuation spring 128 exerts a force against the proximal end of
the piston to maintain the piston within the cylinder. As the fluid
pressure within the syringe barrel and pressure relief assembly
builds up to exceed the counteracting force of the actuation spring,
the piston is pushed out of the cylinder. Thus, the spring actuated
piston limits the pressure within the cylinder as well as inflation
tube 125 and syringe barrel 103.
Syringe 101 is a standard, well-known, and commercially available
10 cc syringe from Becton Dickinson & Company, Rutherford, New
Jersey. This syringe has an outer barrel diameter of approximately
, 0.630" with an overall length of 3.75". Flanges 112
and 113 extend an equal distance laterally and radially from the
proximal end of the barrel and have a maximum cross-sectional dimension
of 1.107" and a minimum cross-sectional dimension of 0.74".
The overall length of plunger 102 is approximately 4" with
the crisscrossed elongated members being approximately 0.500"
in width. The disk-like flange 118 has a diameter of approximately
0.730".
FIG. 2 depicts an end view of drive 100 looking into open distal
end 106 of elongated member 104 through longitudinal passageway
107 toward closed proximal end 105. Also depicted are first plurality
of internal threads 108 with first start 109 and second plurality
of internal threads 110 with second start 111. As previously indicated,
starts 109 and 111 are diametrically opposite each other in the
passageway about distal open end 106 of the drive. Extending f rom
closed proximal end 105 into hollow longitudinal passageway 107
is pivot projection 115 for engaging and pushing against the proximal
end of the plunger and, in particular, the disk-like plunger flange.
As the drive is rotated with respect to the barrel, the plunger
flange pivots about projection 115 without deforming or twisting
the plunger. Also shown is elongated member wall 131 with a plurality
of longitudinally positioned reinforcement ribs 132 positioned about
external surface 133 of the member. The thickness of wall 131 is
approximately 0.050". Longitudinal passageway 107 has a major
diameter 142 of approximately 1.134" and a minor diameter 143
of approximately 0.774".
Rotational pressure drive 100 is molded from a commercially available
medical grade nylon material. The overall length of the drive is
approximately 3.375" with an outside surface diameter of 1.238".
The six reinforcement ribs 132 are each comprised of a 0.187"
diameter semicircular longitudinal rib which are spaced equally
around and longitudinally along the outer surface 133 of the elongated
member, which extends longitudinally for approximately 3.0".
The outside diameter of closed proximal end 105 is approximately
1.017", which is annularly recessed from the outer surface
of the drive and extends longitudinally for approximately 0.285".
FIG. 3 depicts a partial, longitudinal, cross-sectional profile
view of internal threads 134 and 135 of first plurality 108 and
internal threads 136 and 137 of second plurality 110. Internal threads
134 and 135 of plurality 108 include respective crests 138 and 139
with a thickness of approximately 0.034" to 0.035". Crests
140 and 141 of respective internal threads 136 and 137 of second
plurality 110 are also approximately 0.034" to 0.035"
in thickness. Height 160 of internal threads 134-137 is equal to
half the difference between major and minor diameters 142 and 143
which is approximately 0.180". Pitch 161 between internal threads
134 and 136 is approximately 0.125", whereas pitch 162 between
internal threads 134 and 135 of first plurality 108 is approximately
0.250". Roots 144-146 are approximately 0.081" in width.
However, the width of roots 144 and 145 may independently vary depending
on the thickness of syringe barrel flanges 112 and 113. The width
of internal threads 134-137 at diameter 142 of the passageway is
approximately 0.044". Leading flank surfaces 147-150 of respective
threads 134-137 each have a well-known flank angle 163 of approximately
2 degrees as opposed to an Acme flank angle of approximately 14.5
degrees. This angle can preferably range from 1.8 to 2.2 degrees
for a 10 cc Becton and Dickinson syringe. Pressure flank surfaces
151-154 of respective internal threads 134-137 each have a predetermined
flank angle 164 of approximately 2 degrees, again in contrast to
a 14.5 degree Acme flank surface angle. Again, depending on the
type of flanges utilized, the leading and pressure flank surfaces
may have different flank angles as well as having different leading
and pressure flank angles on each of the two internal thread pluralities.
Alternatively, internal thread pluralities 108 and 110 may also
be considered as a single plurality of threads with multiple starts
109 and 111. The aforedescribed thread profile clearly constitutes
a departure and modification from that of an Acme thread profile
with dual starts and equal width crests and roots. The reader is
referred to Machinery's Handbook, Twenty-first and Twenty-third
Editions, Industrial Press Incorporated, New York, New York, for
a more detailed description of the terms utilized herein to describe
the internal threads and their constituent parts. Many of the definitions
contained therein to describe thread parts are hereby incorporated
by reference.
FIG. 4 depicts a longitudinal cross-sectional view of drive 100
of FIG. 2 along the line 4--4. As shown, elongated member 104 of
the drive, such as a hollow cylindrical chamber, has closed proximal
end 105 and open distal end 106 with passageway 107 extending therebetween.
Closed proximal end 105 has a wall thickness of approximately 0.115".
Pivot projection 115 with a height of 0.025", extends into
the passageway along the longitudinal axis thereof. As shown, first
plurality of internal threads 108 extends almost the entire length
of the passageway, and similarly, second plurality of internal threads
110 is alternatingly positioned between the threads of first plurality
108. Start 111 of second plurality of internal threads 110 begins
about open distal end 106 of the passageway.
FIG. 5 depicts the longitudinal cross-sectional view of drive 100
of FIG. 4 with syringe 101 positioned within passageway 107 of elongated
member 104. Plunger 102 extends proximally from syringe barrel 103
with disk-like flange 118 engaging and making contact with pivot
projection 115. Syringe barrel flanges 112 and 113 are positioned
in diametrically opposed roots of internal thread pluralities 108
and 110. As a result, distal end 155 of plunger 102 is pushed into
chamber 156 of the syringe barrel as drive 100 is rotated with respect
to syringe barrel 103. Furthermore, the pressure of fluid 157 contained
within the chamber of the barrel is increased.
FIG. 6 depicts pressure relief assembly 120 attached to distal
end 121 of syringe 101 via syringe connector 122 and assembly connector
124. Extending through end cap 126 is inflation tube 125 which
communicates with the interior of an angioplasty balloon or other
medical dilation device (not shown) . As the pressure of fluid 157
in chamber 156 of the syringe increases, a force is exerted against
distal end 158 of pressure relief piston 127. When the fluid pressure
exceeds the counteracting force exerted by actuation spring 128
the piston is pushed toward end cap 129 releasing fluid 157 around
piston 127 and through cylinder 123 and aperture 159 of end cap
129 until the fluid pressure and spring force are once again equal.
FIG. 7 is an enlarged view of cylinder 123 and piston 127 of pressure
relief assembly 120. As illustrated, the pressure of fluid 157 has
exceeded the force exerted by actuation spring 128 thereby pushing
piston 127 out of cylinder 123 thereby releasing fluid 157 around
piston 127 and through cylinder 123 and out aperture 159 of end
cap 129.
FIG. 8 depicts a partially sectioned side view of rotational pressure
drive 165 which represents another aspect of the present invention.
Pressure drive 165 is positionable about and rotationally engageable
with commercially available, 10 cc syringe 166 for pushing drive
plunger 167 into syringe barrel 168 to control the pressure of fluid
169 contained within the barrel. The drive comprises elongated member
170 such as a hollow cylindrical chamber that was described previously,
having a partially closed, proximal end 171 with opening 172 therethrough.
The elongated member also includes open distal end 173 and hollow
passage 174 extending between the proximal and distal ends for receiving
and extending drive plunger 167 therethrough. The drive also includes
a first plurality of internal threads 175 with start 177 and a second
plurality of internal threads 176 with start 178 for engaging diametrically
opposed syringe barrel flanges 179 and 180. These flanges extend
radially and laterally from proximal end 181 of syringe barrel 168.
The first and second plurality of internal threads with their respective
starts form means for engaging respectively the laterally extending
flanges of the syringe barrel. The rotational pressure drive also
includes plunger 167 having a distal portion 182 and a proximal
portion 183. The plunger also includes a radial projection 184 extending
laterally therefrom between the distal and proximal portions for
engaging partially closed, proximal end 171 for forcing distal end
186 of the plunger into chamber 187 of the syringe barrel. As the
distal end of the plunger is urged into the syringe barrel chamber
with the rotation of the drive about flanges 179 and 180 of the
syringe barrel, fluid 169 in syringe barrel chamber 187 is compressed,
thereby increasing the pressure of the fluid in the chamber. Partially
closed end 171 of the elongated member and opening 172 therein form
means for engaging radial projection 184 of the plunger.
Each thread of the plurality of internal threads 175 and 176 has
a predetermined height, a crest having a predetermined thickness,
and a root having a predetermined width as previously discussed
with respect to the embodiment of FIG. 3. Each thread of the plurality
of internal threads further includes a flank surface having a predetermined
flank angle as also discussed with the embodiment depicted in FIG.
3. Furthermore, the alternatingly positioned internal threads of
pluralities 175 and 176 include respective starts 177 and 178 positioned
opposite each other about open end 173 of the elongated member of
the drive. The pluralities of internal threads comprise a first
and a second continuous helix of which the internal threads are
positioned alternatingly between each other. Passageway 174 of elongated
member 170 includes a major diameter and a minor diameter similar
to the major and minor diameters 142 and 143 as depicted in and
described with respect to FIG. 2. Again, the properties of the internal
threads are similar to and variable as described with respect to
internal threads 108 and 110 depicted in FIGS. 1-5. The drive further
includes well-known expansion retaining pins 185 positioned as shown
in FIG. 8 for maintaining syringe flanges 179 and 180 in passageway
174 of elongated member 170.
Rotational pressure drive 165 also includes a rotational control
collar 188 threadably engaging distal end 189 of syringe barrel
168. The rotational control collar maintains purchase of the syringe
barrel as the pressure drive is rotated in a clockwise manner for
urging plunger 167 into syringe barrel chamber 187.
Plunger 168 of the pressure drive includes proximal end cap 190
positioned at proximal end 191 of the plunger. During assembly of
the pressure drive, proximal plunger portion 183 without end cap
190 is positioned through opening 172 in partially closed, proximal
end 171 of the elongated member. Once positioned through opening
172 proximal end cap 190 is snap fitted in a well-known manner
onto longitudinally slotted proximal end 191 of the plunger.
FIG. 9 depicts a side view of disassembled proximal end 191 of
plunger 167 of FIG. 8 with partially sectioned end cap 190. Proximal
portion 183 of plunger 167 includes longitudinal slot 192 extending
centrally into the plunger from proximal end 191. This provides
for the radial compression of plunger members 193 and 194 inwardly
to pass through ridged opening 195 of end cap 190. Extending into
opening 195 is annular ridge 196 which engages annular recess 197
circumferentially positioned around proximal portion 183 near proximal
end 191 and longitudinal slot 192. Proximal end cap 190 is snap
fitted over the proximal end of the plunger in a well-known manner
as depicted in FIG. 10.
FIG. 10 depicts a partially sectioned side view of assembled proximal
end 191 of proximal plunger portion 183 of FIG. 8 with proximal
end cap 190 positioned thereon.
The method of manually filling and controlling the pressure of
a fluid such as 186 in a syringe barrel with drive 165 includes
the following. Distal portion 182 of plunger 167 is inserted into
syringe barrel 168. Elongated member 170 is urged toward the syringe
barrel so that internal thread pluralities 175 an 176 with respective
starts 177 and 178 of elongated member 170 engage laterally and
radially extending flanges 179 and 180 of the syringe barrel. Proximal
portion 183 of the plunger is pulled through opening 172 of partially
closed end 171 of the elongated member to draw fluid 169 into chamber
187 of the barrel. Elongated member 170 of the drive is rotated
with respect to syringe 167 to engage radial projection 184 of the
plunger with the partially closed end of the elongated member. As
elongated member 170 of the pressure drive is rotated with respect
to the syringe barrel, distal end 186 of the plunger is urged into
syringe barrel chamber 187 to compress fluid 169 and increase the
pressure thereof. The rotation of the drive with respect to the
syringe includes threading the flanges into the internal thread
pluralities that extend into the passageway of the elongated member.
Pulling the plunger through the opening of the partially closed
end of the elongated member also fills the barrel chamber with fluid
169 as previously suggested.
FIG. 11 depicts rotational pressure drive 198 which represents
still another aspect of the present invention for engaging and pushing
syringe plunger 199 into a syringe barrel to control the pressure
of a fluid contained therein. Rotational pressure drive 198 comprises
elongated member 200 having a partially closed, proximal end 201
with opening 202 formed therethrough. Elongated member 200 such
as a hollow chamber, includes open distal end 203 for reception
of proximal end 204 of the plunger. The elongated member includes
passageway 205 extending longitudinally between the open and partially
closed ends for passage of the plunger therethrough. Internal thread
pluralities 206 and 207 as previously described, extend radially
into and longitudinally along the passageway, which forms means
for engaging the radially extending flanges of a syringe barrel.
Rotational pressure drive 198 also includes an axial extension member
208 which is movable through opening 202 of the partially closed,
proximal end for engaging proximal end 204 of the plunger and pulling
the plunger toward the partially closed, proximal end of the elongated
member. The properties of the internal thread pluralities are as
previously described. The axial extension member includes a proximal
end cap 209 positioned at proximal end 210 of the extension member.
Proximal end 210 of the extension member 208 is inserted through
opening 202 of partially closed, proximal end 201 of the elongated
member, and end cap 209 is snap fitted thereon in a well-known manner
and as previously described with respect to FIGS. 8-10. Enlarged
distal end 211 of the extension member includes a distal end chamber
212 with a U-shaped, distal opening 213 communicating with the chamber
to form a well-known T-slot extending therein from the distal end
thereof. Proximal end cap 204 of the plunger is inserted into the
T-slot for pulling the plunger through the passageway through the
partially closed, proximal end of the elongated member. Chamber
212 also includes projection 214 extending into the chamber, as
depicted in FIG. 11 for engaging distal end cap 204 of plunger
199.
FIG. 12 depicts a pictorial view of enlarged distal end 211 of
axial extension member 208 of the rotational pressure drive. T-slot
chamber 212 is shown with U-shaped, distal end opening 213 leading
thereto. Projection 214 is shown extending into the chamber, again,
for engaging proximal end cap 204 of the plunger, so as to allow
the plunger end cap to rotate without distortion as elongated member
200 is threaded onto the flanges of the syringe barrel.
FIG. 13 depicts a partially sectioned side view of rotational pressure
drive 198 of FIG. 11 with axial extension member 208 extending through
opening 202 of partially closed, proximal end 201 of the chamber.
Enlarged distal end 211 of the axial extension member has distal
end cap 204 of syringe plunger 199 cradled in T-slot chamber 212.
The enlarged distal end of the axial extension member along with
the distal end cap of the syringe plunger is depicted engaging the
partially closed, proximal end 201 of elongated member 200. In this
position, distal end 215 of the syringe plunger is shown fully withdrawn,
having pulled fluid 216 into chamber 217 of syringe barrel 218.
Internal thread pluralities 206 and 207 engage laterally and radially
extending flanges 219 and 220 of the syringe barrel.
The method of manually filling and controlling the pressure in
syringe barrel 218 with rotational pressure drive 198 includes the
steps of engaging plunger 199 with axial extension member 208. In
particular, enlarged distal end 211 of the extension member is extended
from open end 203 of elongated member 200 and distal end cap 204
of syringe plunger 199 is inserted into T-slot chamber 212. The
method further includes respectively engaging internal thread pluralities
206 and 207 with flanges 219 and 220 of the syringe barrel by the
longitudinal and rotational movement of elongated member 200 of
the drive. Axial extension member 208 is grasped and pulled by an
attendant to pull plunger 199 into passageway 205 and toward partially
closed, proximal end 201 to fill syringe barrel chamber 217 with
fluid 216. Elongated member 200 of the drive is then rotated with
respect to the syringe to engage the plunger with the partially
closed end of the elongated member. Once engaged, the elongated
member of the drive is further rotated with resect to the syringe
barrel to urge distal end 215 of the syringe plunger into the syringe
barrel chamber. As a result, fluid 216 in syringe barrel chamber
217 is compressed and the pressure thereof increased.
It is to be understood that the above-described rotational pressure
drive is merely an illustrative embodiment of the principles of
this invention and that other rotational pressure drives may be
devised by those skilled in the art without departing from the spirit
and scope of this invention. In particular, the height of the threads
as well as the root and crest may be varied according to the length,
width, and thickness of the radially extending syringe flanges.
These may be varied to accommodate two or more flanges with a corresponding
number of starts and pluralities of internal threads within the
passageway of the hollow elongated member. It is also contemplated
that the threads about the open end of the chamber may be spaced
closer together to provide less force to initiate the initial progress
of the syringe plunger in the syringe barrel. As the pressure in
the syringe barrel is increased, the threads positioned further
in the passageway of the drive may be spread apart to provide greater
longitudinal movement through the hollow passageway. In the preferred
embodiment, one rotation of the drive corresponds to a decrease
in the volume of the fluid within the syringe barrel of 1 cc. The
pitch of the threads may be lengthened or shortened to vary the
amount of fluid compression within the syringe barrel. It is also
contemplated that the actuation spring of the pressure relief assembly
may also be varied to provide different threshold release pressures
along with other pressure relief mechanisms being attached to the
distal end of the syringe barrel. In the preferred embodiment, the
rotational pressure drive has been designed for a commercially available
and commonly used 10 cc syringe. The dimensions of the drive may
be varied to accommodate any commercially available syringe without
any modification to the syringe, therefore making the use of this
drive very economical and efficient without having to modify the
structure of the syringe in any aspect. It is also contemplated
that other forms of multiple start threads, such as the buttress,
square, and other threads or combinations thereof may also be modified
for the rotational pressure drive. The plunger of the syringe can
be engaged with any type of axial extension member to draw the plunger
and f ill the syringe barrel with fluid. The drive can also be fabricated
to include any type of plunger insertable into a commercially available
syringe barrel that can also be pulled or drawn through the partially
closed end of the drive to f ill the syringe barrel with fluid.
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