U.S. patent application number 11/088318 was filed with the patent office on 2005-10-20 for dual cylinder vacuum pump for medical aspiration system.
Invention is credited to Ross, Rod.
Application Number | 20050234394 11/088318 |
Document ID | / |
Family ID | 35097212 |
Filed Date | 2005-10-20 |
United States Patent
Application |
20050234394 |
Kind Code |
A1 |
Ross, Rod |
October 20, 2005 |
Dual cylinder vacuum pump for medical aspiration system
Abstract
A dual cylinder pump that is used to create a vacuum in an
aspiration tube of a medical system. The pump includes a first
plunger that moves within a first cylinder and a second plunger
that moves within a second cylinder. Movement of the plungers is
controlled by a motor assembly. The pump includes valves that
control the flow of fluid into and out of the cylinders so that one
cylinder is pulling fluid from the aspiration tube while the other
cylinder is discharging fluid. The pump housing can be constructed
as a cartridge that can be removed and readily sterilized.
Inventors: |
Ross, Rod; (Mission Viejo,
CA) |
Correspondence
Address: |
IRELL & MANELLA LLP
840 NEWPORT CENTER DRIVE
SUITE 400
NEWPORT BEACH
CA
92660
US
|
Family ID: |
35097212 |
Appl. No.: |
11/088318 |
Filed: |
March 23, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60556963 |
Mar 26, 2004 |
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Current U.S.
Class: |
604/35 ;
417/531 |
Current CPC
Class: |
A61M 1/81 20210501; A61M
1/0062 20130101 |
Class at
Publication: |
604/035 ;
417/531 |
International
Class: |
A61M 001/00 |
Claims
What is claimed is:
1. A pump for a medical aspiration system, comprising: a housing
that has an input port, an output port, a first cylinder and a
second cylinder; a first plunger that moves within said first
cylinder; a second plunger that moves within said second cylinder;
a motor assembly that moves said first and second plungers within
said first and second cylinders, respectively; and, a valve
assembly that controls fluid communication between said first and
second cylinders, and said input and output ports.
2. The pump of claim 1, wherein said motor assembly includes a
first motor connected to said first plunger by a first coupler and
a second motor connected to said second plunger by a second
coupler.
3. The pump of claim 1, wherein said first and second plungers move
out of phase relative to each other.
4. The pump of claim 1, wherein said valve assembly includes a
first input valve that controls fluid communication between said
input port and said first cylinder and a second input valve that
controls fluid communication between input port and said second
cylinder.
5. The pump of claim 1, wherein said valve assembly includes a
first output valve that controls fluid communication between said
first cylinder and said output port and a second output valve that
controls fluid communication between said second cylinder and said
output port.
6. A medical system, comprising: an instrument; an aspiration tube
coupled to said handpiece; a pump coupled to said aspiration tube,
said pump including; a housing that has an input port coupled to
said aspiration tube, an output port coupled to said aspiration
tube, a first cylinder and a second cylinder; a first plunger that
moves within said first cylinder; a second plunger that moves
within said second cylinder; a motor assembly that moves said first
and second plungers within said first and second cylinders,
respectively; a valve assembly that controls fluid communication
between said first and second cylinders, and said input and output
ports; and, a control device coupled to said pump.
7. The system of claim 6, wherein said motor assembly includes a
first motor connected to said first plunger by a first coupler and
a second motor connected to said second plunger by a second
coupler.
8. The system of claim 6, wherein said first and second plungers
move out of phase relative to each other.
9. The system of claim 6, wherein said valve assembly includes a
first input valve that controls fluid communication between said
input port and said first cylinder and a second input valve that
controls fluid communication between input port and said second
cylinder.
10. The system of claim 6, wherein said valve assembly includes a
first output valve that controls fluid communication between said
first cylinder and said output port and a second output valve that
controls fluid communication between said second cylinder and said
output port.
11. The system of claim 6, wherein said control device includes a
foot pedal.
12. The system of claim 11, further comprising a controller coupled
to said foot pedal and said pump.
13. A method for creating a vacuum pressure within an aspiration
tube of a medical system, comprising: moving a first plunger within
a first cylinder of a housing and moving a second plunger within a
second cylinder of the housing; and, switching at least one valve
to create fluid communication between an input port of the housing
and the first and second cylinders and a fluid communication
between an output port of the housing and the first and second
cylinders, so that movement of the first and second plungers create
a vacuum within an aspiration tube coupled to the input port.
14. The method of claim 13, wherein the first and second plungers
move out of phase with each other.
15. The method of claim 13, wherein the first plunger is moved by a
first motor and the second plunger is moved by a second motor.
16. The method of claim 13, wherein the vacuum pressure irrigates
fluid from an eye.
17. A pump cartridge that can be connected to an aspiration tube of
a medical system and a motor assembly of a pump, comprising: a
housing that has an input port that can be connected to the
aspiration tube, an output port, a first cylinder and a second
cylinder; a first plunger that moves within said first cylinder and
can be connected to said motor assembly; a second plunger that
moves within said second cylinder and can be connected to said
motor assembly; and a valve assembly that controls fluid
communication between said first and second cylinders, and said
input and output ports.
18. The pump cartridge of claim 17, wherein said first and second
plungers move out of phase relative to each other.
19. The pump cartridge of claim 17, wherein said valve assembly
includes a first input valve that controls fluid communication
between said input port and said first cylinder and a second input
valve that controls fluid communication between input port and said
second cylinder.
20. The pump cartridge of claim 17, wherein said valve assembly
includes a first output valve that controls fluid communication
between said first cylinder and said output port and a second
output valve that controls fluid communication between said second
cylinder and said output port.
Description
REFERENCE TO CROSS-RELATED APPLICATIONS
[0001] This application claims priority to provisional application
No. 556,963 filed on Mar. 26, 2004.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a vacuum pump for a medical
aspiration system.
[0004] 2. Background Information
[0005] Ophthalmic procedures are typically performed with
instruments that have a tip located at the distal end of a
handpiece. The handpiece is held by a surgeon who inserts the tip
into the inner ocular chamber of an eye. By way of example, the
surgeon may remove a cataracteous lens, or reattach a retina with
the instrument.
[0006] During a procedure, irrigation fluid is introduced into the
eye to maintain the ocular pressure of the anterior chamber. The
handpiece tip is coupled to an aspiration system that pulls the
irrigation fluid and possibly tissue out of the anterior chamber.
The tissue and irrigation fluid flow through an inner channel in
the tip.
[0007] The aspiration system includes a pump coupled to an
aspiration tube. The aspiration tube is connected to an outlet port
of the handpiece. Most aspiration pumps are of the peristaltic type
because the pump behavior is predictable. A peristaltic pump
essentially pushes the air/fluid within the aspiration tube to
create a vacuum pressure within the tube. The operation of a
peristaltic pump creates surges in the pressure within the system.
Pressure surges can be undesirable when performing delicate
procedures such as retinal reattachment.
[0008] Some aspiration systems contain a venturi type pump. Venturi
pumps do not creates pressure surges and are thus typically used in
delicate ophthalmic procedures. Commercially available venturi
pumps require a tank of compressed nitrogen gas. It is generally
undesirable to have a pressurized gas tank in an operating
environment. Additionally, venturi pumps are energy inefficient in
creating a vacuum.
SUMMARY OF THE INVENTION
[0009] A pump for a medical aspiration system. The pump includes a
housing with an input port, an output port, a first cylinder and a
second cylinder. A motor assembly of the pump moves a first plunger
within the first cylinder and a second plunger within a second
cylinder. The pump includes valve assemblies that control fluid
communication between the input/output ports and the cylinders.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a schematic of an embodiment of a medical
system;
[0011] FIG. 2 is an illustration of a dual cylinder pump of the
medical system.
DETAILED DESCRIPTION
[0012] Disclosed is a dual cylinder pump that is used to create a
vacuum in an aspiration tube of a medical system. The pump includes
a first plunger that moves within a first cylinder and a second
plunger that moves within a second cylinder. Movement of the
plungers is controlled by a motor assembly. The pump includes
valves that control the flow of fluid into and out of the cylinders
so that one cylinder is pulling fluid from the aspiration tube
while the other cylinder is discharging fluid. In this manner the
pump is continuously pulling vacuum, thereby preventing vacuum
surges found in peristaltic pumps of the prior art. Additionally,
the pump is relatively energy efficient and does not require a
separate nitrogen tank as required by commercially available
venturi pumps of the prior art. The pump can be constructed as a
cartridge that can be removed and disposed.
[0013] Referring to the drawings more particularly by reference
numbers, FIG. 1 shows an embodiment of a medical system 10 of the
present invention. The system 10 may be used by a surgeon to
perform ophthalmic medical procedures such as cataract lens
removal, or retina reattachment.
[0014] The system 10 may include an instrument 12 that is coupled
to an aspiration system 14. The instrument 12 may include a tip 16
that extends from a handpiece 18 and can be held by a surgeon. The
tip 16 can be inserted into the eye of a patient.
[0015] The aspiration system 14 may include an aspiration tube(s)
20 that is coupled to the instrument 12. The aspiration tube 20 is
connected to a vacuum pump 22 and a collection canister 24. The
vacuum pump 22 creates a vacuum pressure within the aspiration tube
20 and a flow of fluid from the instrument 12 to the canister 24.
The aspiration system 14 can pull emulsified tissue and fluid from
the instrument 12 and into the canister 29.
[0016] The system 10 may include a controller 26 that is connected
to the instrument 12 and the vacuum pump 22. The system 10 may
further have a control device such as a foot pedal 28 that is
connected to the controller 26. The surgeon can control the
instrument 12 and/or the pump 22 thru the foot pedal 28. The
controller 26 may include a processor, memory, etc. (not shown)
that can operate the pump 22 in synchronization with the instrument
12. Although the foot pedal 28 is shown as being connected to the
controller 26, the foot pedal 28 may be connected directly to the
pump 22 and/or instrument 12.
[0017] FIG. 2 shows an embodiment of the vacuum pump 22. The pump
22 may include a housing 30 that has a first cylinder 32 and a
second cylinder 34. The housing 30 also includes an input port 36
and an output port 38. The input port 36 includes channels 40 and
42 in fluid communication with the first 32 and second cylinders
34, respectively.
[0018] The pump 22 may have a first valve assembly 44 that controls
the flow of fluid between the cylinders 32 and 34 and a manifold
tube 46. The manifold tube 46 is connected to the aspiration tube
20 of the aspiration system 14. The first valve assembly 44 may
include a first input valve 48 that controls the flow of fluid into
the first cylinder 32 and a second input valve 50 that controls the
flow of fluid into the second cylinder 34.
[0019] The pump 22 may further have a second valve assembly 52 that
controls the flow of fluid between the cylinders 32 and 34 and
outlet lines 54 and 56 of the output port. The second valve
assembly 52 may include a first output valve 58 that controls the
flow of fluid from the first cylinder 32 and a second output valve
60 that controls the flow of fluid from the second cylinder 34. The
valves 48, 50, 58 and 60 may be controlled actuators or motors that
are connected to and controlled by the controller 26 shown in FIG.
1.
[0020] The pump 22 may include pressure transducers 62 and 64 that
sense the pressure within the first 32 and second 34 cylinders,
respectively. The pressure transducers 62 and 64 can be connected
to the controller 26 shown in FIG. 1, and provide pressure feedback
information that can be used in a feedback control loop of the pump
22.
[0021] The pump 22 includes a first plunger 66 that moves within
the first cylinder 32 and a second plunger 68 that moves within the
second cylinder 34. The plungers 66 and 68 are moved by a motor
assembly 70. The motor assembly 70 may include a first motor 72
that moves the first plunger 66 and a second motor 74 that moves
the second plunger 68. The motors 72 and 74 may move the plungers
66 and 68 out of phase relative to each other. By way of example,
the plungers 66 and 68 may move 180 degrees out of phase relative
to each other. The motors 72 and 74 may be connected to the
controller 26 which controls the timing and phase of the plungers
66 and 68. Although two motors are shown and described, it is to be
understood that the plungers could be coupled to a single
motor.
[0022] The motors 72 and 74 may be attached to the plungers 66 and
68 by couplers 76 and 78. The couplers 76 and 68 may be of the
quick disconnect type so that the plungers 66 and 68, and housing
30 can be detached from the motor assembly 70. This allows the
housing 30 and plungers 66 and 68 to be packaged as a cartridge
that can be detached after a medical procedure. The plungers 66 and
68 may be of the syringe type that can be readily discarded and
replaced. The housing 30 can be sterilized for reuse in the system
10. The valve actuators and pressure transducers may also be
attached to the housing 30 in a sealed and readily detachable
manner so that these components do not have to be sterilized after
each procedure.
[0023] The controller 26 may control the motors 72 and 74 and the
valve assemblies 44 and 52 in the following manner. The first input
valve 48 may be opened to provide fluid communication between the
manifold tube 46 and the first cylinder 32. The second input valve
50 is closed. The first motor 72 may pull the first plunger 66 in a
direction indicated by the arrow. Movement of the plunger 66 pulls
fluid into the first cylinder 32.
[0024] When the first plunger 66 reaches an end of travel the first
input valve 48 is closed and the second input valve 50 is opened.
The second motor 74 then pulls the second plunger 68 to draw fluid
into the second cylinder 34. During this second plunger movement
the first motor 72 pushes the first plunger 66. The first output
valve 58 is opened so that the fluid within the first cylinder 32
is pushed out of the pump 22. The motors and valves are operated so
that one of the cylinders is pulling in fluid while the other
cylinder is pushing out fluid. In this manner a continuous vacuum
is created in the aspiration tube. There are not sudden surges as
found in prior art peristaltic pumps.
[0025] To maintain a continuous vacuum level, the second plunger 68
may begin to pull a vacuum in cylinder 34 as the first plunger 66
nears the end of travel in cylinder 32. Valve 50 may be closed
during movement of the second plunger until the transducers 62 and
64 sense the same pressure wherein valve 50 is opened and valve 48
is closed.
[0026] While certain exemplary embodiments have been described and
shown in the accompanying drawings, it is to be understood that
such embodiments are merely illustrative of and not restrictive on
the broad invention, and that this invention not be limited to the
specific constructions and arrangements shown and described, since
various other modifications may occur to those ordinarily skilled
in the art.
[0027] For example, although multiple values 48, 50, 58 and 60 are
shown and described, it is to be understood that the pump 22 may
have other value arrangements. By way of example the pump 22 may
have a single four-way valve.
* * * * *