U.S. patent application number 12/250365 was filed with the patent office on 2009-04-16 for syringe pump.
This patent application is currently assigned to KOREA INSTITUTE OF MACHINERY & MATERIALS. Invention is credited to Tae-Young Chung, Young-Bog Ham, Jung-Ho Park, Woo-Suk Seo, So-Nam Yun.
Application Number | 20090097995 12/250365 |
Document ID | / |
Family ID | 40534399 |
Filed Date | 2009-04-16 |
United States Patent
Application |
20090097995 |
Kind Code |
A1 |
Ham; Young-Bog ; et
al. |
April 16, 2009 |
SYRINGE PUMP
Abstract
A syringe pump is disclosed, which uses the linear actuator
applying a linear motion of a piezoelectric linear motor in moving
the piston, such that suction and exhaustion of the fluid can be
performed more precisely through controlling of power supply with
respect to the piezoelectric linear motor. The syringe pump
includes a cylinder which includes a receiving space, a piston
which is mounted in the cylinder to pump liquid or powder in and
out of the cylinder, and a piezoelectric linear actuator which
moves the piston in a reciprocating manner. In addition, the
piezoelectric linear actuator comprises a piezoelectric linear
motor.
Inventors: |
Ham; Young-Bog; (Daejeon,
KR) ; Park; Jung-Ho; (Daejeon, KR) ; Yun;
So-Nam; (Daejeon, KR) ; Seo; Woo-Suk;
(Daejeon, KR) ; Chung; Tae-Young; (Daejeon,
KR) |
Correspondence
Address: |
SEED INTELLECTUAL PROPERTY LAW GROUP PLLC
701 FIFTH AVE, SUITE 5400
SEATTLE
WA
98104
US
|
Assignee: |
KOREA INSTITUTE OF MACHINERY &
MATERIALS
Daejeon
KR
|
Family ID: |
40534399 |
Appl. No.: |
12/250365 |
Filed: |
October 13, 2008 |
Current U.S.
Class: |
417/419 |
Current CPC
Class: |
A61M 5/14216 20130101;
A61M 2205/0294 20130101; A61M 5/31515 20130101; A61M 5/1452
20130101 |
Class at
Publication: |
417/419 |
International
Class: |
F04B 17/00 20060101
F04B017/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 15, 2007 |
KR |
10-2007-0103742 |
Claims
1. A syringe pump comprising: a cylinder which includes a receiving
space; a piston which is mounted in the cylinder to pump liquid or
powder in and out of the cylinder; and a piezoelectric linear
actuator which moves the piston in a reciprocating manner.
2. The syringe pump according to claim 1, wherein the piezoelectric
linear actuator comprises a piezoelectric linear motor performing a
linear motion.
3. The syringe pump according to claim 1, further comprising a rod
mounted between the piston and the linear actuator.
4. The syringe pump according to claim 2, further comprising a rod
mounted between the piston and the linear actuator.
5. The syringe pump according to claim 3, wherein the rod includes
a connection protrusion formed in a spherical shape on a surface
thereof facing the piston, and the piston includes a connection
recess formed in a spherical shape and ball-jointed with the
connection protrusion.
6. The syringe pump according to claim 4, wherein the rod includes
a connection protrusion formed in a spherical shape on a surface
thereof facing the piston, and the piston includes a connection
recess formed in a spherical shape and ball-jointed with the
connection protrusion.
7. The syringe pump according to claim 5, further comprising a
sealant member mounted around the outer circumference of the
piston.
8. The syringe pump according to claim 6, further comprising a
sealant member mounted around the outer circumference of the
piston.
9. The syringe pump according to claim 7, further comprising: a
needle connection part having a small diameter, being disposed an
inlet and outlet end; and a needle removably connected to the
needle connection part.
10. The syringe pump according to claim 8, further comprising: a
needle connection part having a small diameter, being disposed an
inlet and outlet end; and a needle removably connected to the
needle connection part.
Description
BACKGROUND
[0001] 1. Technical Field
[0002] The present invention relates to a syringe pump for suction
and exhaustion of a fixed quantity, and more particularly to a
syringe pump, which is capable of taking in and out a fixed
quantity of liquid or powder (hereinafter, collectively referred to
as "fluid") more precisely by moving a piston using a linear
actuator.
[0003] Especially, the above syringe pump uses the linear actuator
which applies linear motion of a piezoelectric motor in order to
move the piston, such that suction and exhaustion of the fluid can
be performed more precisely through controlling of power supply
with respect to the piezoelectric linear motor.
[0004] 2. Description of the Related Art
[0005] Generally, a fixed quantity feeder system is used to supply
a precise quantity of chemical solution in a laboratory or medical
substance as a medical instrument.
[0006] In such a fixed quantity feeder system, a stepping motor is
generally used as a driving means for controlling the movement of a
piston.
[0007] However, the conventional fixed quantity feeder system has
such a complicated structure that manufacturing thereof is
difficult. Furthermore, since the structure is hard to be in a
compact size, handling of the system is inconvenient.
[0008] In addition, the stepping motor conventionally applied in
the fixed quantity feeder system may sometimes cause vibration or
resonance at certain frequency, thereby deteriorating the function
of supplying a fixed quantity fluid.
BRIEF SUMMARY
[0009] Therefore, the present invention has been made in view of
the above problems, and it is an object of the present invention to
provide a syringe pump, capable of controlling movement of a piston
more precisely.
[0010] Especially, it is another object of the present invention to
provide a syringe pump, capable of controlling a moving distance of
a piston more precisely by intermittently supplying power to a
linear actuator that moves the piston, and accordingly precisely
controlling quantity of fluid being taken in and out of a
cylinder.
[0011] More preferably, it is yet another object of the present
invention to provide a syringe pump, capable of reducing the whole
size of the pump by using the piezoelectric linear motor as a
linear actuator.
[0012] In accordance with an aspect of the present invention, there
is provided a syringe pump comprising a cylinder which includes a
receiving space, a piston which is mounted in the cylinder to pump
liquid or powder in and out of the cylinder, and a piezoelectric
linear actuator which moves the piston in a reciprocating
manner.
[0013] In addition, the piezoelectric linear actuator may comprise
a piezoelectric motor constituted by piezoelectric mediums.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The above and other objects, features and other advantages
of the present invention will be more clearly understood from the
following detailed description taken in conjunction with the
accompanying drawings, in which:
[0015] FIG. 1 is a sectional view of a syringe pump according to an
embodiment of the present invention;
[0016] FIG. 2 is an exploded perspective view showing a piston and
an actuator of the syringe pump shown in FIG. 1;
[0017] FIG. 3 is a sectional view of a syringe pump according to
another embodiment of the present invention; and
[0018] FIG. 4 is an exploded perspective view showing a piston and
an actuator of the syringe pump shown in FIG. 3.
DETAILED DESCRIPTION
[0019] Hereinafter, an exemplary embodiment of the present
invention will be described in detail with reference to the
accompanying drawings such that those who are skilled in the art
can easily understand and implement the present invention.
[0020] FIG. 1 is a sectional view of a syringe pump according to an
embodiment of the present invention, and FIG. 2 is an exploded
perspective view showing a piston and an actuator of the syringe
pump shown in FIG. 1.
[0021] FIG. 3 is a sectional view of a syringe pump according to
another embodiment of the present invention, and FIG. 4 is an
exploded perspective view showing a piston and an actuator of the
syringe pump shown in FIG. 3.
[0022] As shown in the drawings, the syringe pump includes a linear
actuator 3.
[0023] More specifically, the syringe pump according to the
embodiment of the present invention comprises a cylinder 1 which
includes a receiving space, a piston 2 which is mounted in the
cylinder 1 to move liquid or powder in and out with respect to the
cylinder 1, and a linear motor 3 which moves the piston 2 in a
reciprocating motion.
[0024] In the above-structured syringe pump with the piezoelectric
linear motor, the cylinder 1 and the piston 2 are used to take in
certain liquid or micro powder and exhaust the liquid or powder to
a desired place, having a similar structure with a syringe. The
liquid and powder will be referred to as fluid.
[0025] That is, the cylinder 1 is formed as a tube holding a
receiving space 1a for receiving the fluid. As shown in FIG. 1 and
FIG. 3, one end of the cylinder 1 is totally open while the other
end is sealed but having an inlet and outlet hole to let the fluid
move in and out.
[0026] The cylinder 1 further includes a needle connection part 11
having a small diameter at the inlet and outlet hole such that the
fluid can be supplied to or taken in from a narrow space as
desired. Additionally, a needle 4 is removably connected to the
needle connection part 11.
[0027] As shown in FIGS. 1 and 3, the needle 4 comprises a
longitudinal fluid hole 4a having a very small diameter, and a
piston connection part 41 fixed to the needle connection part
11.
[0028] The above cylinder 1 and needle 4 are structured in
substantially the same manner as those of a general syringe.
Therefore, the structure of the present invention can be achieved
by adding a piston which includes the linear actuator 3 to the
general conventional syringe.
[0029] The linear actuator 3 constituting the syringe pump, as
shown in the drawings, is preferably implemented by a piezoelectric
linear motor in order to reciprocate the piston 2.
[0030] The piezoelectric linear motor is a sort of motor that
applies the principle in that a piezoelectric element contracts and
expands according to power supply. As shown in the drawings, the
piezoelectric linear motor includes a plurality of legs extending
and contracting in a certain direction like a motion of an inchworm
in accordance with power supply, thereby moving by itself or moving
other parts in a pushing manner. Since the piezoelectric linear
motor is generally known and applied in the art, detailed
description thereof will be omitted herein.
[0031] In the above structure, as shown in FIG. 1 and FIG. 2, the
piston 2 includes a connection recess 21 having a spherical shape
for connection with a connection protrusion 31 having a spherical
shape formed on a bottom surface of the linear actuator 3, so that
the linear actuator 3 can be directly connected with the piston
2.
[0032] In a case where the piston 2 is thus directly connected to
the linear actuator 3, the piston 2 is moved as the linear actuator
3 moves along an inner wall of the cylinder 1.
[0033] In other words, the linear actuator 3 shown in FIG. 1 and
FIG. 2 can move the piston 2 by moving by itself.
[0034] Another method for achieving connection between the piston 2
and the linear actuator 3 is illustrated in FIG. 3 and FIG. 4.
[0035] As shown in the drawings, a rod 5 may be additionally
mounted between the piston 2 and the linear actuator 3.
[0036] More specifically, as shown in FIG. 3 and FIG. 4, the rod 5
is used to connect the piston 2 to the linear actuator 3 and
therefore, the piston 2 is moved as the rod 5 is moved up and down
by the operation of the linear actuator 3. That is, the linear
actuator 3 pushes the rod 5, while being fixed to the inner wall of
the cylinder 1.
[0037] Furthermore, when the piston 2 is connected thus using the
rod 5, the linear actuator 3 used in the embodiment of the present
invention can also be easily adopted in existing syringe pumps.
[0038] As shown in the drawings, a connection protrusion 51 having
a spherical shape is formed at an end of the rod 5, facing the
piston 2 so as to connect the rod 5 with the piston 2. In addition,
the piston 2 is formed with the connection recess 21 of a spherical
shape for force-fit with the connection protrusion 51.
[0039] Thus, since connection parts of the rod 5 and the piston 2
are structured in the form of the spherical protrusion and the
spherical recess, respectively, the piston 2 can be moved
vertically in the cylinder 1 even when the rod 5 is inclined to a
certain direction.
[0040] In addition, a sealant member 2a is mounted around the outer
circumference of the piston 2 to prevent leakage of the fluid
through a gap between the piston 2 and the cylinder 1.
[0041] In the above-structured syringe pump, the linear actuator 3
may have various modified configurations according to the present
invention. Also, the embodiment is illustrated in the drawings only
by way of example, but does not limit the present invention.
[0042] As can be appreciated from the above description, in
accordance with a syringe pump according to the embodiment of the
present invention, control of a moving distance of a piston can be
performed more precisely by intermittently supplying power to a
linear actuator. As a result, quantity of fluid taken in and out of
a cylinder can be precisely controlled.
[0043] Especially, since the piezoelectric linear motor is used as
a linear actuator for operating the piston, the syringe pump can be
achieved in a compacter size.
[0044] Although the preferred embodiments of the present invention
have been disclosed for illustrative purposes, those skilled in the
art will appreciate that various modifications, additions and
substitutions are possible, without departing from the scope and
spirit of the invention as disclosed in the accompanying
claims.
* * * * *