U.S. patent application number 11/391757 was filed with the patent office on 2007-10-25 for cassette having elastomeric clamping ribs.
This patent application is currently assigned to Alcon, Inc.. Invention is credited to Nader Nazarifar, David L. Williams.
Application Number | 20070248477 11/391757 |
Document ID | / |
Family ID | 38171153 |
Filed Date | 2007-10-25 |
United States Patent
Application |
20070248477 |
Kind Code |
A1 |
Nazarifar; Nader ; et
al. |
October 25, 2007 |
Cassette having elastomeric clamping ribs
Abstract
A cassette having a molded flow channel contained on an
elastomeric sheet that is bonded or mechanically attached to a
rigid substrate. A surgical console contains a cassette receiving
area having a pump head with rollers that are mounted radially from
the axis of rotation of the pump motor and compress the elastomeric
flow channels against the rigid substrate. The cassette is held in
place against the pump head by a latching mechanism that draws the
cassette against the pump head. The periphery of the elastomeric
sheet contains a raised ridge or boss integrally formed as part of
the elastomeric sheet at or near the area(s) of the elastomeric
sheet that is/are subject to high transient or static pressures.
The ridge allows the elastomeric sheet to be firmly pressed against
the cassette receiving portion of the surgical console, yet still
allow the cassette to be drawn against the pump head. The firm
engagement of the sheet ridge against the cassette receiving
portion of the surgical console helps to ensure that the
elastomeric sheet does not become dislodged when the cassette is
exposed to high transient pressures.
Inventors: |
Nazarifar; Nader; (Laguna
Nigel, CA) ; Williams; David L.; (Newport Beach,
CA) |
Correspondence
Address: |
ALCON
IP LEGAL, TB4-8
6201 SOUTH FREEWAY
FORT WORTH
TX
76134
US
|
Assignee: |
Alcon, Inc.
|
Family ID: |
38171153 |
Appl. No.: |
11/391757 |
Filed: |
March 29, 2006 |
Current U.S.
Class: |
417/477.2 |
Current CPC
Class: |
A61M 2205/12 20130101;
A61M 1/0058 20130101 |
Class at
Publication: |
417/477.2 |
International
Class: |
F04B 43/12 20060101
F04B043/12 |
Claims
1. A cassette, comprising: a) a body having an exterior; b) a first
relatively flexible elastomeric sheet attached to the body, the
first sheet containing at least one molded pumping channel
projecting outwardly from the exterior of the body; and c) a raised
rib extending along the entire area of the first elastomeric sheet
that is subject to high transient or static pressures.
2. The cassette of claim 1 further comprising at least a second
flexible elastomeric sheet, the second elastomeric sheet having a
raised rib extending along the entire area of the second
elastomeric sheet that is subject to high transient or static
pressures.
3. The cassette of claim 2 wherein the second flexible elastomeric
sheet comprises a pneumatics elastomer.
4. The cassette of claim 2 wherein the second flexible elastomeric
sheet comprises an aspiration elastomer.
5. The cassette of claim 2 wherein the second flexible elastomeric
sheet comprises a pump elastomer.
6. The cassette of claim 2 wherein the second flexible elastomeric
sheet comprises a valve elastomer.
7. The cassette of claim 2 wherein the second flexible elastomeric
sheet comprises an infusion elastomer.
8. A cassette, comprising: a) a body having an exterior; b) a first
relatively flexible elastomeric sheet attached to the body, the
first flexible sheet projecting outwardly from the exterior of the
body; and c) a raised rib extending along the entire area of the
first flexible elastomeric sheet that is subject to high transient
or static pressures.
9. The cassette of claim 8 further comprising at least a second
flexible elastomeric sheet, the second elastomeric sheet having a
raised rib extending along the entire area of the second
elastomeric sheet that is subject to high transient or static
pressures.
10. The cassette of claim 9 wherein the second flexible elastomeric
sheet comprises a pneumatics elastomer.
11. The cassette of claim 9 wherein the second flexible elastomeric
sheet comprises an aspiration elastomer.
12. The cassette of claim 9 wherein the second flexible elastomeric
sheet comprises a pump elastomer.
13. The cassette of claim 9 wherein the second flexible elastomeric
sheet comprises a valve elastomer.
14. The cassette of claim 9 wherein the second flexible elastomeric
sheet comprises at least one molded pumping channel.
15. The cassette of claim 9 wherein the second flexible elastomeric
sheet comprises a valve elastomer.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to peristaltic pumps
and more specifically to fluidic cassettes used in ophthalmic
surgical equipment.
[0002] Most prior art peristaltic pumps work by compressing or
squeezing a length of flexible tubing (sometimes between a fixed
race) using a rotating roller head. As the roller head rotates, the
rollers pinch off a portion of the tubing and push any fluid
trapped in the tubing between the rollers in the direction of
rotation. Peristaltic pumps are widely used in medical applications
because of their predictable, constant flow properties. These prior
art systems, however, typically require manual connection of the
pump tube segment around the rotating roller head.
[0003] Prior art peristaltic pumps using rotating roller heads also
typically impart unwanted pressure pulsations. Several pulsation
damping devices have been developed to address this problem (see
e.g., U.S. Pat. No. 4,921,477 (Davis)).
[0004] Another prior art pump is disclosed in U.S. Pat. No.
6,293,926 B1 (Sorensen, et al.) describes a peristaltic pump having
a molded flow channel contained on an elastomeric sheet that is
bonded or mechanically attached to a rigid substrate. The pump head
rollers are mounted radially from the axis of rotation of the pump
motor and compress the elastomeric flow channels against the rigid
substrate. The commercial embodiment of the invention described in
this patent is sold as the INFINITI.RTM. Vision System by Alcon
Laboratories, Inc., Fort Worth, Tex. This surgical console uses a
Fluid Management System or cassette wherein the elastomeric sheet
is friction fit into the rigid substrate without the use of any
adhesives Such a construction method has proven to be extremely
reliable, but this commercial system is intended primarily for
cataract surgery and has no other source of vacuum other than the
peristaltic pump. Therefore, the fluidic system is exposed
primarily to negative pressure or vacuum and is not exposed to
transient high positive pressures, such as are encountered during a
reflux operation in posterior segment surgical procedures using a
venturi pump as the primary source of vacuum. These high positive
pressures can be as high as 700 mm Hg and have the potential to
cause failure at the elastomer/substrate interface if a friction
fit construction technique is used.
[0005] Accordingly, a need continues to exist for a surgical
cassette that reduces the potential for cassette failure under
transient positive pressures.
BRIEF SUMMARY OF THE INVENTION
[0006] The present invention improves upon prior art cassettes by
providing a cassette having a molded flow channel contained on an
elastomeric sheet that is bonded or mechanically attached to a
rigid substrate. A surgical console contains a cassette receiving
area having a pump head with rollers that are mounted radially from
the axis of rotation of the pump motor and compress the elastomeric
flow channels against the rigid substrate. The cassette is held in
place against the pump head by a latching mechanism that draws the
cassette against the pump head. The elastomeric sheet contains a
raised ridge or boss integrally formed as part of the elastomeric
sheet at or near the area(s) of the elastomeric sheet that is/are
subject to high transient or static pressures. The ridge allows the
elastomeric sheet to be firmly pressed against the cassette
receiving portion of the surgical console, yet still allow the
cassette to be drawn against the pump head. The firm engagement of
the sheet ridge against the cassette receiving portion of the
surgical console helps to ensure that the elastomeric sheet does
not become dislodged when the cassette is exposed to high transient
pressures.
[0007] One objective of the present invention is to provide a
peristaltic pump that uses molded elastomeric flow channels.
[0008] Another objective of the present invention is to provide a
peristaltic pump having radially oriented pump rollers.
[0009] Yet another objective of the present invention is to provide
a peristaltic pump having pump rollers that compress elastomeric
flow channels against a rigid substrate.
[0010] Still another objective of the present invention is to
provide a cassette having an elastomeric sheet fitting to a rigid
substrate.
[0011] Still another objective of the present invention is to
provide a cassette having an elastomeric sheet fitting to a rigid
substrate so that the elastomeric sheet does not become dislodged
when the cassette is exposed to high transient pressures.
[0012] These and other advantages and objectives of the present
invention will become apparent from the detailed description,
drawings and claims that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a front perspective view of the cassette of the
present invention.
[0014] FIG. 2 is a rear perspective view of the cassette of the
present invention.
[0015] FIG. 3 is a schematic representation of the surgical
cassette of the present invention installed in a surgical
console.
[0016] FIG. 4 is a rear perspective view of the pump elastomer
sheet used on the cassette of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] As best seen in FIGS. 1-3, cassette 10 of the present
invention generally includes body 11 having front face 12
containing a plurality of fluidic connections 14 for fluidically
connecting cassette 10 to infusion fluid source 20 and surgical
handpiece 22 used during a surgical procedure. Cassette 10 may also
include handle 16 for assisting in installing and removing cassette
10 from surgical console 24. As best seen in FIG. 2, cassette 10
has rear face 18 opposite front face 12 and adapted for mechanical
and fluidic interaction with surgical console 24. Frictionally
mounted on rear face 18 of cassette 10 are a plurality of
elastomeric interface-forming sheets, such as pneumatics elastomer
25, infusion elastomer 26, aspiration elastomer 28, valve elastomer
100 and pump elastomer 30. Cassette 10 is mounted within console 24
so that pump elastomer 30 is pressed against pump mechanism 32
mounted in console 24 by latches 38. Cassette 10 may be molded from
any suitable material, such as thermoplastic and elastomers 25, 26,
28 and 30 may be molded from any suitable elastomer, such as
silicone rubber.
[0018] As best seen in FIG. 4, pump elastomer 30 is generally
circular, approximating the size and shape of the roller head (not
shown) mounted to pump mechanism 32. Pump elastomer 30 contains
pumping channel 34 that interacts with pump mechanism 32 to provide
peristaltic pumping action through cassette 10. The operation of
cassette 10 and pump mechanism 32 is more fully described in U.S.
Pat. No. 6,293,926 B1 (Sorensen, et al.), the contents of which
being incorporated herein by reference. In order to assure that
pump elastomers 25, 26, 28, 30 and 100 are firmly pressed against
console 24, thereby helping to reduce the likelihood that
elastomers 25, 26, 28, 30 and 100 can be dislodged from cassette 10
when exposed to high transient pressures, elastomers 25, 26, 28 and
30 contain raised ribs or bosses 36 extending around the entire
areas of elastomers 25, 26, 28, 30 and 100 that are subject to high
transient or static pressures. Ribs 36 are compressed when latches
38 press cassette 10 into console 24, thereby helping to prevent
any movement of elastomers 25, 26, 28, 30 and 100.
[0019] This description is given for purposes of illustration and
explanation. It will be apparent to those skilled in the relevant
art that modifications may be made to the invention as herein
described without departing from its scope or spirit.
* * * * *