U.S. patent application number 14/373623 was filed with the patent office on 2015-01-01 for tube pump.
This patent application is currently assigned to VEINUX APS. The applicant listed for this patent is VEINUX APS. Invention is credited to Jan Erik Vest Hansen.
Application Number | 20150004034 14/373623 |
Document ID | / |
Family ID | 48798687 |
Filed Date | 2015-01-01 |
United States Patent
Application |
20150004034 |
Kind Code |
A1 |
Hansen; Jan Erik Vest |
January 1, 2015 |
TUBE PUMP
Abstract
The invention relates to a tube pump including an at least
partly flexible tube and a pump element inserted in the tube, where
the pump element comprises no more than one non-return valve member
and a flow blocking member positioned a distance apart on a rod
element. The non-return valve member is oriented on the rod element
so as to allow for a fluid flow in the tube through the valve
member along the rod element in the direction towards the flow
blocking member. The flow blocking member is in a closed
configuration placed to block the tube by engaging with the tube
walls, and is in an open configuration configured to deform by a
deformation of the tube such as to allow for fluid passage. The
flow blocking member further is configured to attain its closed
configuration when not opened by the tube deformation. The tube
comprises an at least partly flexible tube portion between the
valve member and the flow blocking member, such that a repeated
deformation of the flexible tube portion acts to alternately close
and open the valve member and the flow blocking device thereby
generating a fluid flow through the tube. The invention further
relates to an infusion pump comprising such tube pump as mentioned
above.
Inventors: |
Hansen; Jan Erik Vest;
(Aarhus C, DK) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
VEINUX APS |
Aarhus N |
|
DK |
|
|
Assignee: |
VEINUX APS
Aarhus N
DK
|
Family ID: |
48798687 |
Appl. No.: |
14/373623 |
Filed: |
January 21, 2013 |
PCT Filed: |
January 21, 2013 |
PCT NO: |
PCT/DK2013/000009 |
371 Date: |
July 21, 2014 |
Current U.S.
Class: |
417/474 |
Current CPC
Class: |
F04B 43/08 20130101;
F04B 43/084 20130101 |
Class at
Publication: |
417/474 |
International
Class: |
F04B 43/08 20060101
F04B043/08 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 19, 2012 |
DK |
PA 2012 00055 |
May 31, 2012 |
EP |
12170131.2 |
Claims
1. A tube pump comprising an at least partly flexible tube and a
pump element inserted in said tube, the pump element comprising a
rod element, no more than one non-return valve member, and a flow
blocking member, wherein the non-return valve member and the flow
blocking member are positioned a distance apart on said rod
element, and the non-return valve member is oriented on the rod
element so as to allow for a fluid flow in the tube through the
valve member along the rod element in the direction towards the
flow blocking member, wherein the flow blocking member in a closed
configuration is placed to block the tube by engaging with the tube
walls in a fluid tight fashion, and the flow blocking member in an
open configuration is configured to deform by a deformation of the
tube such as to allow for passage of a fluid between the flow
blocking member and the tube walls, and wherein the flow blocking
member is configured to attain its closed configuration when not
opened by said tube deformation, wherein the tube comprises an at
least partly flexible tube portion between said valve member and
said flow blocking member, such that a repeated deformation of said
flexible tube portion acts to alternately close and open the valve
member and the flow blocking device thereby generating a fluid flow
through the tube.
2. The tube pump according to claim 1, wherein the flow blocking
member comprises a foam member.
3. The tube pump according to claim 1, wherein the flow blocking
member comprises a flexible member of a larger outer circumference
than the interior circumference of the tube.
4. The tube pump according to claim 1, wherein the pump element
extends into the tube from one end of the tube, and where the pump
element further comprises at least one sealing part engaging with
the tube wall in a fluid tight fashion in one end of the tube.
5. The tube pump according to claim 1, wherein the pump element
extends through the entire length of the tube and comprises sealing
parts engaging with the tube wall in a fluid tight fashion in both
ends of the tube.
6. The tube pump according to claim 1, wherein the pump element
further comprises a filter placed on said rod element.
7. The tube pump according to claim 1, further comprising at least
one actuator comprising a movable contact plate arranged for
deforming said flexible tube portion by compressing the tube when
actuated.
8. The tube pump according to claim 7, wherein the movable contact
plate is arranged to successively deformed the tube surrounding the
flow blocking member and the tube portion between the valve member
and the the flow blocking member.
9. The tube pump according to claim 1, comprising at least two pump
elements placed serially.
10. The tube pump according to claim 1, where the non-return valve
member comprises a flexible funnel shaped membrane and a perforated
disk fitted onto the rod element, the disk being sized to engage
with the interior of the tube in a fluid tight fashion and the
membrane is sized to cover the disk perforations if pressed against
the disk.
11. The tube pump according to claim 1, wherein the tube pump
further comprises a pipe connection part configured for connecting
the tube pump to a further tube.
12. The tube pump according to claim 1, wherein said non-return
valve member comprises a valve belonging to the group of ball
valves, duckbill valves, diaphragm valves, wafer valves, check
valves, swing check valves, disc check valves, split disc check
valves, tilting disk check valves, cross slit valves, umbrella
valves, and lift-check valves.
13. The tube pump according to claim 1, where the rod element is
made of a bendable material.
14. The tube pump according to claim 1, where the rod element is
made of PE (polyethylene), PP (polypropylene), a rubber, or a metal
alloy.
15. An infusion pump comprising a tube pump according to claim
1.
16. The tube pump according to claim 13, where the connecting rod
is made of a thermoplast.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a tube pump comprising a
pump element inserted in a tube for the generation of a fluid flow
within the tube and for the prevention of free flow and back flow
within the tube. The invention furthermore relates to an infusion
pump comprising such tube pump.
BACKGROUND
[0002] Different kinds of positive displacement tube pumps such as
roller pumps or peristaltic pumps are known for pumping a fluid
through a flexible tube or hose and are widely used in e.g. medical
applications such as for instance in infusion pump systems,
dialysis pumps, or bypass pumps for circulatory support.
[0003] A benefit of such pump types making them especially
advantageous in medical applications is the absence of moving parts
in contact with the fluid, whereby the pumps may be relatively
easily sterilized. The peristaltic pumps, roller pumps and tube
pumps however suffer from a number of drawbacks. Firstly, the
pumping involves a complete or near complete compression or
squeezing of the tube either by rollers, contact plates, or shoes
to obtain the desired fluid flow within the tube. This inevitably
leads to large wear on the part of the tube within the pump. The
tube therefore regularly needs to be moved relative to the pump for
the compression to be exerted on another part of the tube or
exchanged completely thereby resulting in an excessive use of tube
material and a need for longer tubes. The extra tube length or the
moving of the pressure zones makes the known tube pumps more
expensive and increases the time needed to setup and operate the
pump. Further, the large wear increases the risk of damaging the
hose considerably, leading to a loss of pumping fluid and
contamination of the surroundings, and a reduction or loss of
pumping effect which depending on the circumstances may be
unacceptable and even fatal. Extra surveillance of the pump and
tubes is therefore required to prevent such situations.
[0004] Further, the complete or near complete compression of the
tube or hose may result in excessive large stresses and shear
forces experienced by the fluid causing damages to the fluid
molecules or separation of colloids and slurry fluids.
[0005] Another drawback of the known tube pumps is their often
considerable size necessitating a large amount of space which in
many medical situations is limited.
[0006] Another concern of the known tube pumps is to avoid any
undesired back flow in the tube which otherwise will make both the
pump less efficient and less accurate in determining the pump
flow.
[0007] Another drawback of the known tube pumps when used in
infusion pumps is the inherent risk of free flow leading to
uncontrolled delivery of an infusion to a patient. Free-flow of
intravenous infusions has been the cause of several deaths, and
"Near Misses" nationwide according to several health organizations.
Usually the problem occurs when the tubing is removed from the pump
and the infusion flows by gravity (free-flows) overdosing the
patient. In known tube pumps, the problem of free flow is tried to
be removed by built-on applications to the pump system such as
clamps or the like regulation means which must be opened and closed
by a nurse before and after use. However, these systems are
disadvantageous by the extra complexity and time needed to operate
the systems, and the increased risk of human errors in the
operation of the pumps.
DESCRIPTION OF THE INVENTION
[0008] It is therefore an object of embodiments of the present
invention to overcome or at least reduce some or all of the above
described disadvantages of the known tube and peristaltic pumps by
providing a tube pump and a pump element with improved pumping
efficiency and reduced wear of the tube material. It is a further
object of embodiments of the invention to provide pump elements and
tube pumps with minimized risk of leakages.
[0009] It is a further object of embodiments of the invention to
provide a tube pump without or with reduced risk of free flow and
back flow and thereby to increase the safety of using the pump. Yet
a further objective is to provide a tube pump with with a more
stable and precise flow.
[0010] It is a further object of embodiments of the invention to
provide a tube pump which is simple and intuitive to operate and
yet effective. It is a yet further object of embodiments of the
invention to provide an effective tube pump of minimal number of
parts and which may be manufactured fastly by a minimum of
operations and a low manufacturing cost.
[0011] In accordance with the invention this is obtained by a tube
pump comprising an at least partly flexible tube and a pump element
inserted in the tube, where the pump element comprises a rod
element, no more than one non-return valve member, and a flow
blocking member. The non-return valve member and the flow blocking
member are positioned a distance apart on the rod element, and the
non-return valve member is oriented on the rod element so as to
allow for a fluid flow in the tube through the valve member along
the rod element in the direction towards the flow blocking member.
The flow blocking member is in a closed configuration placed to
block the tube by engaging with the tube walls in a fluid tight
fashion, and the flow blocking member is in an open configuration
configured to deform by a deformation of the tube such as to allow
for passage of a fluid between the flow blocking member and the
tube walls, and wherein the flow blocking member is configured to
attain its closed configuration when not opened by said tube
deformation. The tube comprises an at least partly flexible tube
portion between the valve member and the flow blocking member, such
that a repeated deformation of the flexible tube portion acts to
alternately close and open the valve member and the flow blocking
device thereby generating a fluid flow through the tube.
[0012] By a tube pump according to the above may by very simple
means be obtained an effective pump for and mechanism for pumping a
fluid through the tube. The fluid flow is generated as the
deformation of the tube opens the flow blocking member and thereby
acts to squeeze the fluid out of the tube space past the flow
blocking member. When the deformation is relaxed, the flow blocking
member blocks the tube and a negative pressure is created in the
space in turn opening the valve member drawing in fluid from
upstream the tube. A repeated deformation repeats the above
described alternately opening and closing of the flow blocking
member and the valve member thereby generating a fluid flow within
the tube.
[0013] It is noted that whereas the flow blocking member is opened
by the deformation of the tube, the non-return valve member is
opened by the pressure difference between each side of the valve
created as the deformation is relaxed. The flow blocking member is
not opened by a pressure difference across the flow blocking
member.
[0014] The flow blocking member is advantageous in preventing any
fluid flow when the tube is not deformed and pumping is not
intended. Hereby, a reliable and automatic closing of the tube may
be achieved without the need for any manual interaction such as the
conventional manually placing of clamps, fittings, extra valves or
the like on the tube.
[0015] Hereby is obtained that the flow blocking member works to
prevent both back flow and free flow in the tube pump.
[0016] In contrast hereto, the non-return valve member may not in
itself completely prevent any free flow through the tube, as the
valve in some situations could allow unintended flow for example
due to gravitational forces.
[0017] A pumping of the fluid could likewise be obtained by the
replacement of the flow blocking member by a further second
non-return valve. However, in comparison to this, the use of the
flow blocking member according to the invention is advantageous by
effectively preventing both back flow as well as free flow while
maintaining or improving the pumping efficiency and with the use of
only one non-return valve member.
[0018] The flow blocking member further acts to make the open and
closed configurations of the pump, and the phases of the pumping
more distinct.
[0019] By means of the flow blocking member in combination with the
only one non-return valve may be obtained an efficient tube pump
while on the same time obtaining an effective free-flow and
back-flow prevention at all times when the flow blocking member is
not activated. Also, these effects are obtained with the use of a
minimum number of elements as only one non-return valve is needed,
and thereby potentially lower manufacturing time and costs.
[0020] The flow blocking member according to embodiments of the
invention is furthermore advantageous in preventing the free flow
while still allowing the pumping with only small pressure forces on
the tube. The stiffness of the flow blocking member may be tailored
to require a desired minimum deformation of the tube or minimum
deformation force on the tube to enable any fluid flow.
[0021] The prevention of any free flow in the tube pump is
especially important in relation to applications of the tube pump
in infusion pumps, where the unintended free flow of medicine is
estimated to have added to or been the direct cause of death of
about 500 persons in the USA.
[0022] By the tube pump according to the invention incorporating a
flow blocking member is obtained a pump system with a built-in
safety and not--unlike traditional infusion pump systems--with
built-on safety functions. Hereby safety risks and the risk of
human errors are removed or at least greatly reduced as the free
flow prevention is obtained without human interaction and operation
on the tube. Rather, the anti-free flow and anti-back flow is
obtained automatically.
[0023] This is obtained while at the same time having a very simple
construction which is very simple and intuitive to employ and
operate and thereby being very user friendly.
[0024] The deformation may in an embodiment of the invention
involve a compression of the tube from one or more sides and/or may
involve a decompression of the tube.
[0025] The the flow blocking member may simply comprise an elastic
element initially filling out the interior of the tube but
deforming differently from the tube, so that one or more openings
between the element and the tube may occur when the tube is
deformed e.g. as a part of the pumping, and such that the tube will
again be closed when the deformation of the tube seizes.
[0026] The flow blocking member may comprise a foam member
preferably of a foam with closed cells and e.g. of a cubic shape.
The foam member is easily deformed with minimal forces and may be
manufactured and assembled efficiently and at low costs.
[0027] The flow blocking member may comprise an elastic or flexible
member or body of a larger outer circumference than the interior
circumference of the tube. Hereby may be obtained an efficient
prevention of free flow and back flow when the flow blocking member
is in its closed configuration.
[0028] The non-return valve may be a so-called check valve, a clack
valve, or one-way valve, and is a mechanical device, a valve, which
normally will allow a fluid (liquid or gas) to flow through it in
only one direction. The non-return valve may close the fluid
passageway off partly or fully in its closed position. By orienting
the non-return valve as specified above is obtained that the valve
member when in its open position will allow for a fluid flow in the
tube in the desired pumping direction.
[0029] The whole tube may be flexible and may be made in a material
such as a thermoplastic or a rubber, and may be reinforced.
Alternatively or additionally, only a portion of the tube may be
flexible, such as comprising a length of a flexible hose or
comprising flexible tube wall portions.
[0030] The tube pump is further advantageous in comprising only
very few parts and which may be easily and fast assembled with a
minimal number of assembling operations. Also the tube pump is
inexpensive to manufacture and therefore advantageous as a
disposable product, which may be advantageous for medical
applications or in the food industry where hygiene or sterile
equipments are of outmost importance.
[0031] The pump element is further advantageous in being easy and
fast to insert in a tube whereby a tube pump may be made ready for
operation fast and easily.
[0032] Further, because of the pump element construction, the
different components of the pump element (the non-return valve
member and the flow blocking member) will inevitably be inserted in
a tube at the predefined distance apart as given by their position
on the rod element, whereby the amount of pumping may be equally
well defined for a given deformation of the tube.
[0033] Further, the simple construction and way of activating the
tube pump ensures a more stable flow over time leading to a higher
medication precision when used for infusion pumps.
[0034] Unlike many conventional tube pumps such as roller pumps,
the tube need not be completely compressed or squeezed to generate
an efficient pumping motion of the fluid. Rather, even relatively
small deformations of the tube may be enough to obtain a relatively
high pumping efficiency due to the construction of the tube pump
with the pump element comprising only one non-return valve member
and a flow blocking member. This is further advantageous in
minimizing the wear on the tube caused by the repeating deformation
and thereby minimizing the risk of leaking and loss of the fluid
and contamination of the surroundings.
[0035] The smaller amount of deformation of the tube needed for
obtaining an efficient pump further leads to lower stresses and
shear forces experienced by fluid, which may prevent damaging of
fluid molecules and help to keep colloids and slurry fluids from
separating. This may be especially advantageous in pumping of
specific types of fluid such as e.g. blood or other fluids
comprising fragile or vulnerable components.
[0036] Due to the construction of the pump element of the no more
than one i.e. a single non-return valve member and a flow blocking
member positioned on a rod element, a tube may fast and easily made
ready for pumping by simply inserting a pump element into the tube.
Similarly, the pump element may be extracted from the tube in an
equally simple fashion, whereby the interior of the tube which then
is the only part of the pump in contact with the fluid is left
without obstacles and may be cleaned and sterilized easily and
effectively. The extracted pump element is likewise simple to clean
and sterilize effectively before reuse or may simply be disposed
of. This makes the tube pump especially advantageous for medical
applications and in the food industry.
[0037] The tube pump is further advantageous in that it may be
operated to deliver a pulsed flow e.g. like the heart which may be
advantageous in e.g. bypass pumps or in some infusion pumps.
[0038] The pump element may be pre-manufactured in one or more
sizes dimensioned to tubes of different diameters and/or
shapes.
[0039] The tube pump in comprising one single non-return valve
member and the flow blocking member is advantageous in having very
few parts, and can therefore be fast and easily assembled and made
ready for pumping. Further, the tube pump is inexpensive to
manufacture and inexpensive to maintain as the use of a hose or
tube makes for a relatively low-cost maintenance item compared to
other pump types.
[0040] A further advantage is that the tube pump may be constructed
to yield a compact yet robust and efficient pump.
[0041] Because of rod element of the pump element, the valve
members will be positioned in the tube at a predefined distance
apart given by and fixed by the rod element whereby the amount of
pumping may be equally well defined for each deformation of the
tube and possible to determine on beforehand.
[0042] Furthermore, by the rod element being relatively stiff and
inelastic compared to the flexible tube portion, the rod element
aids the tube portion to relax and return to its undeformed shape
after each deformation and each pumping movement. Hereby, the tube
portion may be ready for a new deformation and pumping cycle
faster.
[0043] Further, the rod element enable a fast and simple assembly
of the pump element and the tube pump as all the parts of the pump
element may by mounted one after another on the rod element. The
assembly may advantageously be performed from only one side which
enables a high-speed and automated mass production.
[0044] Also, the rod element enables a fast yet precise and
well-controlled insertion of the pump element into the tube.
[0045] The rod element may further be provided with recesses for
the different parts of the pump element to be placed in. This
facilitates the mounting and positioning of the parts on the rod
element. Furthermore, the distances between the parts and
especially the distance between the valve members and thereby the
pumping volume may hereby be determined and controlled
accurately.
[0046] Also, the predetermined and fixed distance between the valve
members eases the mounting or placing of the tube pump in a pumping
apparatus such as an infusion pump.
[0047] The rod element may attain elongate shapes of different
and/or varying cross sections such as e.g. a circular cylindrical
shape, a rectangular cylindrical shape, a hollow cylindrical shape,
or a helical shape. The rod element may further comprise two or
more parallel or non-parallel bars.
[0048] According to an embodiment of the invention, the pump
element extends into the tube from one end of the tube, and the
pump element further comprises at least one sealing part engaging
with the tube wall in a fluid tight fashion in one end of the tube.
Hereby is obtained that the pumping element is easily inserted into
a tube portion and that the pump element may also act as a coupling
member for coupling the tube to another part such as e.g a further
tube, an infusion bag, a syringe or the like without or with only
minimal leaking. In this way the assembled tube pump may be made
ready with only one connection or coupling.
[0049] The sealing part may engage with the tube wall by friction.
The sealing part may comprise one or more gaskets e.g. in the shape
of a ring or band of rubber or another deformable or flexible
material.
[0050] In a further embodiment of the invention, the pump element
extends through the entire length of the tube and comprises sealing
parts engaging with the tube wall in a fluid tight fashion in both
ends of the tube. Hereby a tube length of a predetermined length
may be pre-manufactured and pre-assembled with the pump element
already inserted and secured to the tube wall. Hereby the sealing
parts may be brought to engage with the tube wall such as to be
able to withstand a higher fluid pressure e.g. by involving heat
sealing or shrinking.
[0051] In a further embodiment of the invention, the tube is
connected to a further tube via a connection part. The connection
part may be configured as a pipe connection part on the end of the
pumping element. Hereby the tube pump may be easily fastened and
secured to e.g. another tube, an infusion bag, syringe or the like
for pumping the fluid to or from such other part. This further
yields the possibility to use less expensive tubes or hoses leading
to or from the tube pump without being constrained by any tube
diameter or tube material applied in the tube pump.
[0052] In a further embodiment of the invention, the pump element
further comprises a filter placed on the rod element. Hereby, the
fluid may effectively be filtered and undesired particles removed
from the fluid flow. The use of a particle filter may be a
requirement in some applications e.g. in infusion where microscopic
clots, cellular debris or undesired particles. By the placing of
the filter on the rod element may be obtained a simple and
effective placing e.g. by pushing the filter onto the rod prior to
inserting the pump element into the tube. Further, the precise
placing of the filter may be ensured by corresponding marks or
indentations on the rod.
[0053] The filter may be disk shaped and be substantially flat or
curved. A curved shape may be advantageous in providing a larger
surface compared to a flat filter whereby the pressure drop across
the filter may be reduced. This may be especially advantageous in
e.g. blood pumping applications due to the higher viscosity of the
blood.
[0054] In yet a further embodiment of the invention, the tube pump
comprises at least one actuator comprising a movable contact plate
arranged for deforming the flexible tube portion by compressing the
tube when actuated. The actuator may be linear or non-linear and
may comprise one or more contact plates placed to move towards each
other and/or towards a base, so that the tube may be compressed
from one or more sides.
[0055] According to a further embodiment, two or more tube pumps
may be placed serially. By the use of a number of pumping elements
placed after each other, the pumping effect may be increased
equivalently by repeatingly deforming the tube in several positions
between sets of valve members. The tube may hereby be deformed in a
peristaltic movement.
[0056] In an embodiment, the valve member comprises a flexible
diaphragm and/or membrane fitted onto the rod element and sized to
at least partly engage in its closed position with the inner wall
of the tube. The pump element and thereby the tube pump may hereby
be constructed of very few parts in that the valve function is
simply obtained by the flexible membrane moving relative to the
inner tube wall. Further, the valve member may be easily positioned
onto the rod element and may be easily exchanged if needed. The
pump element and thereby the tube pump may hereby be manufactured
at very low costs.
[0057] In a further embodiment of the tube pump according to any of
the above described, the non-return valve member comprises a valve
placed in a valve housing which at least partly engage with the
inner wall of the tube. Here, the valve opening is primarily
established in the valve housing, whereby the valve opening is not
dependent on the positioning within the tube and therefore may be
determined precisely beforehand and independent of the tube
properties. Further, such construction may be more robust.
[0058] In a further embodiment of the tube pump according to any of
the above, the non-return valve member may comprise a flexible
funnel shaped membrane in combination with a perforated disk fitted
onto the rod element, the disk being sized to engage with the
interior of the tube in a fluid tight fashion. The membrane may be
sized to cover the disk perforations if pressed against the
disk.
[0059] Hereby is established a very compact yet efficient
non-return valve which may be configured to completely or partly
close off any flow effectively in the one direction while allowing
for a full flow in the other direction caused by a pressure
difference across the valve. The valve may be opened by only a
small pressure in dependence of the material properties and
stiffness of the funnel shaped membrane. The funnel shaped (i.e.
conical, cup shaped, or trumpet shaped) membrane increases the
efficiency of the valve and provides for a smooth continuous
transition from its closed to its open position and vise versa
without any `flapping` or sudden changes of its shape. Hereby, a
more even pumping motion without or with only minimal cudden
changes in the flow speed may be obtained.
[0060] In both the open and closed position of the valve, the disk
lies sealingly against the interior of the tube so that the only
possible fluid flow is through the perforations or openings in the
disk. The funnel shaped membrane is mounted on the rod element only
allowing for any possible fluid flow around the membrane in the
space between the membrane and the tube walls. The membrane is
oriented so that the interior of funnel is oriented towards the
disk. In the closed and relaxed position of the valve, the membrane
lies against the disk. The membrane may lie completely or partly
against the disk surface. Hereby the membrane covers at least some
of the perforations in the disk preventing the fluid flow
therethrough. In the open configuration of the valve, the membrane
is deformed due to the increased pressure on the disk side of the
valve so that a gap is established between the disk and the
membrane allowing for a fluid flow through the perforations in the
disk and around the membrane.
[0061] The perforations in the disk may be applied as openings or
holes through the disk placed randomly or in a pattern. The
perforations may be placed a distance from the rod element or next
to the rod element. The perforations may e.g. be applied to the
disk by the punching of a star shaped central hole in the disk both
functioning as the hole for the disk to be mounted on the rod
element and providing the perforations for the valve function.
[0062] The disk may be manufactured from e.g. a thermoplast, a
metal, or a rubber material.
[0063] The funnel shaped membrane may be punched or cut out from a
foil, a film or a cloth of e.g. a silicone material. The membrane
may have a circular or oval shape with a central hole of a smaller
diameter than the diameter of the rod element (optionally of the
diameter of the recessed rod element) where the membrane is to be
placed. As the membrane then is pushed or drawn onto the rod
element, the initially flat membrane naturally attains a funnel
shape and seals against the rod element. Alternatively, the
membrane may be shaped e.g. by thermoshaping or thermoforming. In
an embodiment of the invention the central part of the funnel
shaped membrane attains an angle in the range of 10-40 degrees
relative to the rod element. In a preferred embodiment the cone
angle lies in the range of 20-35 degrees such as approximately 30
degrees.
[0064] Further, the tube pump may comprises a pipe connection part
configured for connecting the tube pump to a further tube, syringe,
infusion bag or the like. Hereby is obtained that a tube in which a
pumping motion is generated is easily connected and coupled to
another part via the pump element such that fluid may be pumped on
to this other part. In this way a minimum of couplings are needed
and the risk of leaks is minimized.
[0065] In a further embodiment, the non-return valve member
comprises a valve belonging to the group of ball valves, duckbill
valves, diaphragm valves, wafer valves, check valves, swing check
valves, disc check valves, split disc check valves, tilting disk
check valves, cross slit valves, umbrella valves, and lift-check
valves. Hereby may be obtained an effective valve and which may be
pre-manufactured and positioned in the valve member in a simple yet
effective manner.
[0066] In a further embodiment of the invention, the rod element is
made of a bendable material such as a thermoplast. Hereby is
obtained that the pump element may be easily inserted into bended
tubes or hoses or that the tube may be bended without affecting the
efficiency of the pumping. Further, a more compact tube pump may be
obtained by allowing the tube to bend.
[0067] In a further embodiment of the invention, the rod element is
made of a plastic material such as e.g. PE (polyethylene), PP
(polypropylene), a rubber, or a metal alloy.
[0068] The invention further relates to an infusion pump comprising
a tube pump according to any of the embodiments described in the
preceding. The advantages hereof are as given in relation to the
tube pump. Further, the infusion pump is advantageous in making the
use of a drip counter and a flow regulator superfluous, as
otherwise conventionally applied in infusion pumps, as the tube
pump can be controlled and regulated to give a certain number of
pulses per time whereby the flow may be accurately determined.
Further, the infusion pump can maintain a constant flowrate
throughout the entire emptying of the infusion bag and regardless
of how the infusion bag is placed. In contrast hereto conventional
infusion pumps uses the gravity for a continued and complete
emptying of the infusion bag for which reason it may be essential
that the infusion bag and the tube leading from the infusion bag
must hang or be held correctly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0069] In the following different embodiments of the invention will
be described with reference to the drawings, wherein:
[0070] FIG. 1 illustrates an embodiment of a tube pump with a pump
element inserted in a tube as seen in a cross sectional views from
the side,
[0071] FIGS. 2A and 2B illustrates a flow blocking device inserted
in a tube in a closed and open configuration, respectively -in side
and in end views,
[0072] FIGS. 3A and 3B illustrate the working principle of a tube
pump according to the invention during and after deformation of the
tube by an external compression force,
[0073] FIG. 4A-D illustrates the working principle of a tube pump
according to the invention before, during and after deformation of
the tube by compression plates,
[0074] FIG. 5 illustrates an embodiment of a tube pump and a pump
element in an exploded view and a perspective view,
[0075] FIG. 6 illustrates the embodiment of a tube pump of FIG. 5
in a side view and as actuated by compression plates,
[0076] FIG. 7 illustrates an embodiment of a tube pump with a
number of pumping elements in a serial connection, and the coupling
of two tube parts by means of a pump element,
[0077] FIG. 8 illustrates an infusion pump comprising a tube pump
and a pump element according to embodiments of the invention,
and
[0078] FIG. 9 illustrates an embodiment of an activation mechanism
suitable for deforming the tube of a tube pump.
DETAILED DESCRIPTION OF THE DRAWINGS
[0079] FIG. 1 shows an embodiment of a tube pump, 100 according to
the invention and as seen in a cross sectional view. The tube pump
100 comprises a tube 101 (in grey) into which is inserted a pump
element 102. The pump element 102 comprises a non-return valve
member 103 and a flow blocking member 110 attached to a rod element
104 in a spaced apart manner. The valve member 103 is oriented
relative to the flow blocking member 110, so that a fluid inside
the tube portion 101 may only flow in the one direction through the
valve member 103 towards the flow blocking member 110 as
illustrated by the arrow 105. The valve member 103 here is
illustrated as a split disc or duo check valve comprising a split
disk which is dimensioned to have a larger surface area than the
tube cross sectional area so that the disks only allow for a fluid
flow in the one direction. Generally any type of non-return or
one-way valve may be used. The rod element 104 here is in the shape
of a flat bar for optimally supporting the split disk valves but
could also have other shapes such as circular. Other possible
shapes are shown in some of the following figures. The pump element
102 further comprises a connecting part 106 at its end for
connecting to another tube or hose 107. The connection part 106
could equally well be dimensioned and shaped to connect to tubes of
smaller or larger diameters, to e.g. a syringe, or a infusion bag
or the like. The pump element further comprises a sealing part 108
establishing a fluid tight connection between the pump element and
the tube 101 when the pump element is inserted herein. The sealing
part may optionally comprise one or more gaskets (not shown). The
flow blocking member 110 is placed on the rod element such as to
block the tube and prevent fluid flow in either direction in the
tube when in its closed configuration. This is also illustrated in
FIG. 2A showing to the left the tube as seen from the side, and to
the right as seen in an end view. Upon deformation of the tube, the
flow blocking member 110 no longer engage with the surrounding tube
walls and a fluid in the tube can then flow past the flow blocking
member 110. This is illustrated in FIG. 2B. The open configuration
of the flow blocking member 110 is here obtained by the flow
blocking member deforming differently from the tube yielding
passages 201 between the flow blocking member and the tube
walls.
[0080] The flow blocking member 110 is thus configured such that it
only opens and allows for passage of a fluid when affected by a
deformation of the tube e.g. a pressure from the exterior on the
tube. Hereby any unintentional fluid flow through the pump (both
free flow and back flow) may be prevented which may otherwise be
the problem e.g. for hanging infusion pumps where the gravity
forces from a bags of infusion fluids may cause a small
unnoticeable leak in the infusion pump. The flow blocking member
110 may as sketched in FIGS. 1-3 comprise a foam member of a larger
diameter that the interior diameter of the tube 101. As a pressure
is applied to the tube, the tube deforms differently than the flow
blocking member 110 making openings between the member and the tube
wall for the fluid to flow through. When the pressure is released,
the flow blocking member 110 attains its undeformed shape and
closes off any flow through the tube again.
[0081] FIGS. 3A and 3B illustrate the working principle of the tube
pump 101 in general. The tube 101 surrounding the pump element 102
comprises a flexible tube wall portion 301 between the valve member
103 and the flow blocking member 110. The pumping may be generated
by deforming the tube between the valve member 103 and the flow
blocking member 110, which in this illustrated example is performed
by an actuator compressing the tube 101 by means of two movable
contact plates 302. Here, the valve member 103 will remain closed
due to the increased pressure in the tube, whereas the flow
blocking member 110 will be opened by its deformation. Thereby the
fluid is forced in the direction of the arrow 303. As the contact
plates 302 retract (as shown in FIG. 3B) and the tube deformation
is relaxed, the flow blocking member 110 again blocks the tube and
an under pressure is created in the decompressed chamber between
the valve member and the flow blocking member 110. The under
pressure causes the valve member 103 to open and a flow in the
direction of the arrow 304. In contrast to the non-return valve
member, the flow blocking member is not opened by the pressure
difference across the flow blocking member and thereby acts as an
effective anti free flow device. A fluid flow in the tube may
thereby obtained by a simple repeating deformation of the tube
between the valve member 103 and the flow blocking member 110. The
tube pump may further comprise a filter 333 which may
advantageously be placed upstream the non-return valve, i.e. at the
inlet of the pump. The filter may filter the fluid reducing the
risk of any undesired particles being pumped along with the fluid.
The filter 333 may be placed on the rod 104 and thereby inserted in
the tube as the pump element is inserted. In the figure, the filter
is substantially flat but may likewise be of a curved shape and
thereby have a larger surface.
[0082] FIGS. 4A-4D illustrate the same pumping principle, but where
the actuation of the pump is effected by a little more complex
deformation cycle of the tube 101. In this embodiment the tube is
deformed by means of two movable contact plates 302 which first
(FIG. 4B) act to compress both the central tube portion 301 between
the valve member 103 and the flow blocking member 110 and the tube
portion 401 surrounding the flow blocking member 110. In a
following step (FIG. 4C) the pressure is releaved on the flow
blocking member 110 so that this closes while maintaining a
deformation on the central tube portion 301. When the contact
plates then retracts (FIG. 4D) a larger under pressure in the
decompressed chamber between the valve member and the flow blocking
member is then obtained. Hereby the resulting fluid flow may be
increased considerably compared to the simpler pumping sequence as
illustrated in FIG. 3 or the same fluid flow may be obtained by
fewer actuations of the tube.
[0083] FIG. 5 discloses an embodiment of a pump element 102
inserted into a flexible tube thereby forming a tube pump 100. The
figure shows the different parts of the pump elements as assembled
and in an exploded view, respectively. In this embodiment the
non-return valve member 103 comprises a funnel-shaped flexible
membrane 501 of a smaller diameter than the interior diameter of
the tube 101. This membranes may initially be flat membranes of
circular shape provided with a central hole of smaller dimension
than the diameter of the rod element. The membrane may as an
example be punched out or cut from films or foils of a flexible
material such as silicone.
[0084] When pushed onto the rod element, the membrane deform into a
funnel as illustrated in the figure. The funnel shaped membrane is
placed on the rod element 104 next to a disk 502 of an outer
dimension and shape so as to lie and seal against the interior of
the tube. The disks 502 comprise a number of openings 503. When the
non-return valve member is closed as illustrated in the lowermost
assembled view in FIG. 5, the funnel shaped membrane 501 lies
against at least the outer part of the neighbouring disk 502. In
case of a larger fluid pressure to the disk side of the valve (to
the left in the figure) than to the membrane side (to the right in
the figure), the membrane will be pushed away from the disk
allowing for a fluid flow through the openings of the disk and
around the membrane. An increased fluid pressure on the membrane
side of the valve member, however, will cause the membrane to press
more tightly against the disk preventing any fluid flow. The rod
element 104 is provided with recesses for receiving and positioning
the different parts of the pump element whereby the distance
between the non-return valve member and the flow blocking member
110 and thereby the pumping volume can be determined and controlled
accurately.
[0085] The tube pump is configured to be attached to other tubes or
hoses 507 via the connection parts 106 in each end of the pump
element and placed on each end of the rod element 104. The tube
pump may in this way be manufactured from a minimal number of parts
which furthermore may be effectively and fast assembled in a
production line from optionally just one side.
[0086] FIG. 6 illustrates the same tube pump as in FIG. 5 as seen
from the side. FIG. 6 furthermore shows an embodiment of the
contact plates 302 for actuating the pump. The contacting plates
302 are in this embodiment placed tiltable and of a shape to obtain
a successive compression of the flow blocking member 110 and the
central tube portion 301.
[0087] FIG. 7 illustrates an embodiment of a tube pump 100 with a
number of pump elements 102 placed in one or more tubes 101 in a
serial. Hereby the pumping effect may be correspondingly increased,
in that the tube or tubes 101 may be compressed in more than one
place. This may advantageously be done one place after each other
thereby establishing a peristaltic movement. The figure further
illustrates how two or more tube parts 101 may be coupled to each
other and brought in fluid connection by means of the one or more
pump elements 102.
[0088] The contacting plates may be actuated by an actuation
mechanism 900 as illustrated in FIG. 9. Here, the two contacting
plates 302 are anchored in hinges 901 and a sideways movement of
the element 902 causes a symmetrical compression and decompression
movement of the contact plates 302.
[0089] FIG. 8 illustrates an infusion pump 1301 comprising a tube
pump 100 and a pump element 102 according to embodiments of the
invention. Here, the pump element 101 is inserted in a tube,
coupling the tube to a further tube or hose at each end of the pump
element which may be coupled at one end to a syringe 1302 and at
the other to an infusion bag of bottle (not shown). The infusion
pump using a tube pump according to the invention is advantageous
over conventional infusion pumps by being able to provide a
well-controlled and steady flow irrespective of the orientation of
the pump (independent of the gravity force) and irrespective of the
amount of fluid left in the infusion container. Rather the infusion
speed and amount can be precisely controlled and regulated by
controlling the actuator force of the one or more actuators
deforming the flexible tube, 1303.
[0090] The tube pump according to the various embodiments may
likewise advantageously be applied in other types of pumps such as
pumps driven by solar cells for instance in pumps for increased
oxidisation of water where water from lower regions of for instance
a lake or water basin is raised and pumped to higher regions
thereby mixing the water. The disclosed tube pumps may work
efficiently together with solar cells in that the tube pumps may
work in a discontinuous manner whenever power is available, and may
yield at least a single if not several pumping strokes with only
minimal power.
[0091] While preferred embodiments of the invention have been
described, it should be understood that the invention is not so
limited and modifications may be made without departing from the
invention. The scope of the invention is defined by the appended
claims, and all devices that come within the meaning of the claims,
either literally or by equivalence, are intended to be embraced
therein.
* * * * *