U.S. patent application number 11/791485 was filed with the patent office on 2008-06-05 for peristaltic pump.
Invention is credited to Florent Junod, Frederic Neftel.
Application Number | 20080131300 11/791485 |
Document ID | / |
Family ID | 34932384 |
Filed Date | 2008-06-05 |
United States Patent
Application |
20080131300 |
Kind Code |
A1 |
Junod; Florent ; et
al. |
June 5, 2008 |
Peristaltic Pump
Abstract
Peristaltic pump comprising--a pump body (3) with a face
containing at least a first groove (4) covered by a flexible
membrane (2) fixed to said pump body (3), in such a way as to form
a fluid tight channel, said membrane (2) furthermore comprising a
sealing ridge (19) which is in permanent contact against said
groove (4) so as to obtain a resting fluid tight sealing segment in
the channel, --a movable pressure element (7) adapted to
temporarily press a portion of the membrane (2) above said groove
(4) and form a moving sealing segment in the channel, --driving
means (8) adapted to move said movable pressure element (7) along
said groove, said driving means (8) furthermore being adapted to
move said movable pressure element (7) exclusively along a plane
which is parallel to said pump body face, said sealing ridge (19)
and/or said groove (4) being adapted to let said movable pressure
element (7) in said parallel plane when moving over said sealing
ridge (19), characterized by the fact that the movable pressure
element (7) is rotatably fixed to an axis (9) forming part of said
driving means (8), said axis (9) being parallel to the membrane
(2).
Inventors: |
Junod; Florent; (Lausanne,
CH) ; Neftel; Frederic; (Lausanne, CH) |
Correspondence
Address: |
NIXON & VANDERHYE, PC
901 NORTH GLEBE ROAD, 11TH FLOOR
ARLINGTON
VA
22203
US
|
Family ID: |
34932384 |
Appl. No.: |
11/791485 |
Filed: |
October 20, 2005 |
PCT Filed: |
October 20, 2005 |
PCT NO: |
PCT/IB0205/053443 |
371 Date: |
June 18, 2007 |
Current U.S.
Class: |
417/476 |
Current CPC
Class: |
F04B 43/14 20130101;
F04B 43/1269 20130101; F04B 2205/05 20130101; F04B 2205/01
20130101 |
Class at
Publication: |
417/476 |
International
Class: |
F04B 43/14 20060101
F04B043/14 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 26, 2004 |
EP |
04405736.2 |
Claims
1. Peristaltic pump comprising a pump body (3) with a face
containing at least a first groove (4) covered by a flexible
membrane (2) fixed to said pump body (3), in such a way as to form
a fluid tight channel, said membrane (2) furthermore comprising a
sealing ridge (19) which is in permanent contact against said
groove (4) so as to obtain a resting fluid tight sealing segment in
the channel, a movable pressure element (7) adapted to temporarily
press a portion of the membrane (2) above said groove (4) and form
a moving sealing segment in the channel, driving means (8) adapted
to move said movable pressure element (7) along said groove, said
driving means (8) furthermore being adapted to move said movable
pressure element (7) exclusively along a plane which is parallel to
said pump body face, said sealing ridge (19) and/or said groove (4)
being adapted to let said movable pressure element (7) in said
parallel plane when moving over said sealing ridge (19),
characterized by the fact that the movable pressure element (7) is
rotatably fixed to an axis (9) forming part of said driving means
(8), said axis (9) being parallel to the membrane (2).
2. Peristaltic pump according to claim 1 wherein said sealing ridge
is made of an elastomeric material which allows said sealing ridge
to collapse when compressed by the movable pressure element
(7).
3. Peristaltic pump according to claim 1 wherein said groove (4)
contains a zone of greater depth (17), said zone forming a part of
said permanent fluid tight sealing segment and said sealing ridge
(19) being designed to tightly fill said zone of greater depth
(17).
4. Peristaltic pump according to claim 1 wherein said pump body
face contains additional grooves (13,14) and wherein said membrane
(2) contains additional ridges (11,12), said additional ridges
(11,12) being designed to be located in said additional grooves
(13,14) in order to tightly fix the membrane (2) to the pump body
(3).
5. Peristaltic pump according to claim 1 wherein said first groove
(4) forms a non-complete circle.
6. Peristaltic pump according to claim 1 wherein said first groove
(4) forms a complete circle.
7. Peristaltic pump according to claim 6 wherein said first groove
(4) contains a fluid inlet (10) and a fluid outlet (10), said
permanent fluid tight sealing segment being located on the shortest
distance separating said inlet (10) from said outlet (10).
8. Peristaltic pump according to claim 5 wherein said driving means
(8) comprise a crown (15) with a diameter at least identical to the
first groove diameter.
9. Peristaltic pump according to claim 8 wherein the crown (15) is
adapted to be in close contact with the membrane (2) when the
membrane is not pressed by said movable pressure element (7).
10. Peristaltic pump according to claim 1 comprising several
movable pressure elements (7).
11. Peristaltic pump according to claim 10 wherein said movable
pressure elements (7) are separated by a rigid element (16) which
is in close contact with the membrane (2).
12. Peristaltic pump according to claim 11 wherein said rigid
element (16) contains several smaller movable pressure elements
such as balls adapted to freely rotate on the membrane (2) when the
driving means (8) are activated.
13. Peristaltic pump according to claim 1 wherein said pump body
face contains at least another cavity (21) forming part of an
element such as a valve, a pressure sensor, a flow sensor or a hub
chamber, said other cavity being also covered by the membrane
(2).
14. Peristaltic pump according to claim 1 wherein said membrane (2)
is tightly fixed to the pump body.
15. Peristaltic pump according to claim 1 furthermore comprising a
pressure sensor located within the channel entry, said pressure
sensor being connected to a flow compensating means in such a way
that any pressure difference recorded by said pressure sensor would
adapt the fluid flow accordingly.
16. Peristaltic pump according to claim 1 furthermore comprising a
pressure sensor located within the channel exit, said pressure
sensor being connected to a flow compensating means in such a way
that any pressure difference recorded by said pressure sensor would
adapt the fluid flow accordingly.
17. Peristaltic pump according to anyone of the previous means
furthermore comprising a flow compensating means, based on membrane
wear, which is adapted to automatically correct the fluid flow
after a certain time and/or a certain number of pumping cycles.
18. Peristaltic pump according to anyone of the previous means
wherein said movable pressure element is a ball (7).
Description
FIELD OF INVENTION
[0001] The present invention relates to a peristaltic pump which
may be used in the medical field, e.g. administration of drugs or
of contrast media, peritoneal dialysis, etc . . . .
[0002] More precisely, the invention relates to a peristaltic pump
of the "membrane" type.
STATE OF THE ART
[0003] Peristaltic pumps of the "membrane" type comprise a pumping
cavity covered by a flexible membrane. Fluid is moved in the cavity
by a moving pressure wave applied to the membrane. The pressure
wave can be obtained by a plurality of pressure elements situated
along the cavity or by one or some moving pressure elements.
[0004] Examples of such peristaltic pumps can be found in patent
documents U.S. Pat. No. 5,044,902, DE 197 17 452, DE 199 226 12 or
DE 1 528 971.
[0005] When the cavity contains an inlet and an outlet, the fluid
has to be directed along a specific path (the pumping path). To
this effect, a sealing element has to be placed between the inlet
and the outlet.
[0006] In DE 1 528 971, the sealing element is made of a ridge
forming part of the membrane.
[0007] A similar configuration is disclosed in U.S. Pat. No.
5,533,886 (see FIG. 9) which relates to a peristaltic pump
comprising: [0008] a pump body with a face containing at least a
circular pumping cavity covered by a flexible membrane fixed to
said pump body, in such a way as to form a fluid tight channel. The
membrane has a sealing ridge which is in permanent contact against
a specific zone of the cavity so as to obtain a resting fluid tight
sealing segment in the cavity, [0009] a movable roller adapted to
temporarily press a portion of the membrane above the cavity and
form a moving sealing segment in the cavity, [0010] a driving shaft
adapted to rotatably move the roller along the cavity.
[0011] In order that the roller can shift away from the bottom of
the cavity in the region of the sealing segment, the driving shaft
is mounted in an axial bearing which permits the drive shaft to
move axially, i.e. against the action of a spring.
[0012] Shifting away the roller from the bottom of the cavity makes
the system more complex, increases the pump wear and reduces the
pumping precision.
SUMMARY OF THE INVENTION
[0013] The present invention provides a solution to the above cited
problems.
[0014] It concerns a peristaltic pump which comprises: [0015] a
pump body with a face containing at least a first groove covered by
a flexible membrane fixed to said pump body, in such a way as to
form a fluid tight channel, said membrane furthermore comprising a
sealing ridge which is in permanent contact against said groove so
as to obtain a resting fluid tight sealing segment in the channel,
[0016] a movable pressure element adapted to temporarily press a
portion of the membrane above said groove and form a moving sealing
segment in the channel, [0017] driving means adapted to move said
movable pressure element along said groove. The driving means are
adapted to move the movable pressure element exclusively along a
plane which is parallel to said pump body face, the sealing ridge
and/or the groove being adapted to let said movable pressure
element in said parallel plane when moving over said sealing
ridge.
[0018] The peristaltic pump is characterized by the fact that the
ball is rotatably fixed to an axis forming part of said driving
means, said axis being parallel to the membrane.
[0019] The presence of an axis around which the movable pressure
element can freely rotates offers the following advantages, in
particular an improved rolling movement.
[0020] There exits several ways to obtained to achieved effect,
i.e. maintaining the movable pressure in a same plane during its
movement.
[0021] In one embodiment of the sealing ridge is made of an
elastomeric material which allows the sealing ridge to collapse. In
this case, the sealing ridge is designed to reach a position which
places the complete membrane external face which is pressed in the
same plane.
[0022] In another embodiment, the groove contains a zone of greater
depth. This deeper forms a part of the permanent fluid tight
sealing segment. The sealing ridge being designed to tightly fill
the deeper zone.
[0023] One preferred embodiment for fixing the membrane to the pump
body consists in providing the pump body with a second groove and
in providing the membrane with a second ridge. The second ridge is
designed to be located in the second groove and to therefore
tightly fix the membrane to the pump body.
[0024] Advantageously the movable pressure element is a ball which,
preferably, is rotatably fixed to an axis forming part of the
driving means. The axis is parallel to the membrane.
[0025] In one alternative, the groove forms a portion of a
circle.
[0026] In another alternative, the groove forms at least a complete
circle. In this case, the groove may contain a fluid inlet and a
fluid outlet. The permanent fluid tight sealing segment being then
located on the shortest distance separating said inlet from said
outlet. This forces the fluid to move on the greatest distance.
Alternatively the groove may consist of a complete circle and two
connected branches, one branch containing the inlet and the other
branch containing the outlet.
[0027] If the groove has a circular or a partial circular shape,
the driving means may comprise a crown with a diameter at least
identical to the first groove diameter.
[0028] In a preferred embodiment the crown is adapted to be in
close contact with the membrane when the membrane is not pressed by
said movable pressure element. Such a configuration ensures a more
regular flow in the channel.
[0029] The peristaltic pump may also contain several balls which,
preferably, are separated by a rigid element being in close contact
with the membrane. The rigid element may contain several balls of
relatively small diameter which are adapted to freely rotate on the
membrane when the driving means are activated.
[0030] In another embodiment the pump body face contains at least
another cavity forming part of an element such as a valve, a
pressure sensor or a hub chamber. The other cavity is also covered
by the membrane. For instance, the peristaltic pump according to
the invention may be incorporated in a liquid distribution system
similar to the one disclosed in international patent application
PCT/CH2004/000480 filed by the applicant of the present
invention.
[0031] Preferably, in order to have a regular flow in the channel,
the membrane is tightly fixed to the pump body.
[0032] In another embodiment the peristaltic pump comprises a
pressure sensor located within the channel entry, the pressure
sensor being connected to a flow compensating means, including e.g.
a microprocessor, in such a way that any pressure difference
recorded by said pressure sensor would adapt the fluid flow
accordingly.
[0033] Alternatively or in addition, the pressure sensor may be
located within the channel exit.
[0034] Alternatively or in addition the peristaltic pump comprises
flow compensating means, based on membrane wear, which is adapted
to automatically correct the fluid flow after a certain time and/or
a certain number of pumping cycles.
[0035] Other features and advantages of the invention will become
apparent from the following description of examples when read in
conjunction with the accompanying drawings.
[0036] FIG. 1 is a perspective view of an example of the
peristaltic pump according to the invention.
[0037] FIG. 2 is a sectional/longitudinal view of the pump of FIG.
1.
[0038] FIG. 3 is a perspective view from above of a ball bearing
unit with balls.
[0039] FIG. 4 is a perspective view from bellow of the ball bearing
unit of FIG. 3.
[0040] FIG. 5 is a perspective view from above of a membrane
plate.
[0041] FIG. 6 is a perspective view from bellow of the membrane
plate of FIG. 5.
[0042] FIG. 7 is a perspective view from above of a membrane.
[0043] FIG. 8 is a perspective view from bellow of the membrane of
FIG. 8.
[0044] FIG. 9 is a perspective view from a pump body.
[0045] FIG. 10 is a perspective view of a liquid distribution
system incorporating a pump according to the invention.
LIST OF NUMERICAL REFERENCES USED IN THE FIGURES
[0046] 1. Membrane plate [0047] 2. Membrane [0048] 3. Pump body
[0049] 4. Fluid groove [0050] 5. Transversal ridge [0051] 6. Linear
branch [0052] 7. Ball [0053] 8. Ball bearing [0054] 9. Ball axis
[0055] 10. Inlet/Outlet [0056] 11. External fixing ridge [0057] 12.
Internal fixing ridge [0058] 13. External fixing groove [0059] 14.
Internal fixing groove [0060] 15. Crown [0061] 16. Crown segment
[0062] 17. Groove deeper zone [0063] 18. Membrane deeper zone
[0064] 19. Membrane protruding part [0065] 20. Membrane transversal
ridge. [0066] 21. Valve, pressure sensor, hub chamber, etc . . .
.
[0067] The example of FIG. 1 shows a pump according to the
invention including all essential elements. FIGS. 2 to 9 show some
of the elements of FIG. 1 which are taken separately.
[0068] The pump body 3 contains a circular groove 4 which extends
in two parallel branches 6. Each branch 6 contains an inlet or an
outlet 10 through which liquid can enter or exit the circular
groove 4.
[0069] The groove 4 and the branches 6 are covered by a membrane 2
made of flexible material. The membrane 2 is covered by a membrane
plate 1 which is fixed to the pump body 3. In order to have a fluid
tight connection between the membrane 2 and the groove 4, the
membrane is provided with an external ridge 11 and an internal
ridge 12 which are located in a corresponding external groove 13
and an internal groove 14 contained in the pump body 3.
[0070] The membrane 2 is not covered by the membrane plate 1 in the
central part and above the groove.
[0071] The groove 4 contains a zone of greater depth 17 having a
transversal groove 5. On its internal face, the membrane 2 contains
a protruding part 19 with a transversal ridge 20 which represents a
negative reproduction of the groove deeper zone 17 and transversal
groove 5.
[0072] This configuration forms a resting fluid sealing segment in
the groove 4, i.e. in order to go from the inlet to the outlet,
liquid is forced to use the groove longest path.
[0073] On its external face, the membrane 2 contains a cavity 18
which is approximately identical in shape to the zone of greater
depth 17 and the transversal groove 5.
[0074] A ball bearing unit 8 is rotatably positioned above the
membrane central part. The ball bearing unit 8 contains several
freely rotating balls 7 which can freely rotate around axis 9 which
are parallel to the membrane 2. The ball bearing unit 8 is mounted
rotatable around a vertical axis so that the balls 7 can move along
the groove 4. The bottom part of the ball bearing unit 8 forms a
crown 15. The crown segments 16 which are situated between the
balls 7 are in close contact with the membrane upper face.
[0075] When the pump is activated, the balls 7 are moving along the
groove 4 and simultaneously press the membrane 2 against the groove
bottom to such an extend that a plurality of moving fluid sealing
segments are created and moved from the inlet to the outlet.
[0076] When passing over the groove deeper 17 zone, i.e. the
resting fluid sealing segment, the balls 7 are not vertically
shifted away.
[0077] In the present example the balls move exclusively in the
same plane thanks to the specific configuration of the groove
deeper zone 17.
[0078] Other possibilities are offered to obtain the same effect.
For instance (not illustrated) in choosing a membrane sealing ridge
which collapse when the balls cross the resting fluid sealing
segment.
[0079] FIG. 10 shows a possibility to include a pump according to
the invention in a liquid distribution system, e.g. as defined in
international patent application PCT/CH2004/000480. The liquid
distribution system may contain several cavities 21 forming part of
a valve, pressure sensor, hub chamber or any similar object.
* * * * *