U.S. patent application number 11/989255 was filed with the patent office on 2009-08-27 for mechanical liquid pump.
Invention is credited to Harald Hansmann, Christian Kenzler, Roland Wex.
Application Number | 20090214364 11/989255 |
Document ID | / |
Family ID | 39530453 |
Filed Date | 2009-08-27 |
United States Patent
Application |
20090214364 |
Kind Code |
A1 |
Wex; Roland ; et
al. |
August 27, 2009 |
Mechanical liquid pump
Abstract
A mechanically operated liquid pump for medical and nutrient
liquids, as well as for liquids used in biological and laboratory
applications, has an integrated, self-contained pump construction
comprising a housing having an expandable elastic member mounted
wholly within the housing and shaped to store and dispense a liquid
therefrom. Inlet and outlet members are also mounted within the
housing, are operably connected with the elastic member inside the
housing, and regulate the flow of liquid traveling into and out of
the pump. A flow regulator is also mounted wholly within the
housing, communicates with at least one of the inlet and outlet
members, and maintains a substantially constant volumetric flow of
liquid dispensed from the elastic member.
Inventors: |
Wex; Roland; (Melsungen,
DE) ; Hansmann; Harald; (Wismar, DE) ;
Kenzler; Christian; (Pritzwalk, DE) |
Correspondence
Address: |
PRICE HENEVELD COOPER DEWITT & LITTON, LLP
695 KENMOOR, S.E., P O BOX 2567
GRAND RAPIDS
MI
49501
US
|
Family ID: |
39530453 |
Appl. No.: |
11/989255 |
Filed: |
July 21, 2006 |
PCT Filed: |
July 21, 2006 |
PCT NO: |
PCT/EP2006/007204 |
371 Date: |
March 17, 2009 |
Current U.S.
Class: |
417/474 |
Current CPC
Class: |
A61M 5/168 20130101;
A61M 5/141 20130101; A61M 5/152 20130101; G05D 16/0641 20130101;
F04B 43/0063 20130101; A61M 5/16877 20130101; A61M 5/14244
20130101; A61M 2205/3331 20130101; A61M 5/16881 20130101; F04B
13/00 20130101 |
Class at
Publication: |
417/474 |
International
Class: |
F04B 43/08 20060101
F04B043/08 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 22, 2005 |
EP |
05 015 965.6 |
Claims
1-17. (canceled)
18. In a mechanically operated liquid pump for medical and nutrient
liquids, as well as for liquids used in biological and laboratory
applications and the like, the improvement comprising an
integrated, self-contained pump construction, comprising: a housing
member; an expandable elastic member mounted wholly within said
housing member, and shaped to store and dispense a liquid
therefrom; a closeable inlet member mounted within said housing
member, operably connected with said elastic member at a location
inside said housing member and regulating the flow of liquid
traveling into said elastic member; an outlet member mounted within
said housing member, operably connected with said elastic member at
a location within said housing member and routing the liquid
traveling out of said elastic member; and a flow regulator member
mounted wholly within said housing member, communicating with one
of said inlet member and said outlet member, and maintaining a
substantially constant volumetric flow of the liquid dispensed from
said elastic member.
19. A pump as set forth in claim 18, wherein: said elastic member,
said inlet member, said outlet member and said flow regulator
member are each calibrated to ensure substantially constant
volumetric flow of the liquid.
20. A pump as set forth in claim 19, wherein: said housing member
has a sealed construction, such that at least said inlet member,
said outlet member and said flow regulator member cannot be removed
from said housing member without destroying said pump.
21. A pump as set forth in claim 20, wherein: said inlet member
comprises one of either a Luer lock valve or a Luer lock
attachment; and said outlet member comprises the other of said Luer
lock valve and said Luer lock attachment.
22. A pump as set forth in claim 21, including: a core member
mounted in said housing member and including a channel therethrough
for delivery and dispensing of the liquid into and out of said
elastic member; and wherein said elastic member comprises a balloon
having an open end portion thereof sealingly mounted on said
core.
23. A pump as set forth in claim 22, wherein: said flow regulator
member comprises a pressure control valve.
24. A pump as set forth in claim 22, wherein: said flow regulator
member comprises a glass capillary or meander chip.
25. A pump as set forth in claim 24, including: a filter member
mounted within said housing member and disposed upstream of said
flow regulator member.
26. A pump as set forth in claim 25, wherein: said housing member
includes a middle portion, an upper portion and a lower
portion.
27. A pump as set forth in claim 26, wherein: said housing member
includes a cap detachably connected with said upper and lower
portions of said housing member, and enclosing said balloon and
said core therein.
28. A pump as set forth in claim 27, wherein: at least one of said
core, said balloon, said outlet member, said filter member and said
flow regulator member has at least a portion thereof mounted in
said middle portion of said housing member.
29. A pump as set forth in claim 28, wherein: at least one of said
core, said balloon, said outlet member, said filter member and said
flow regulator member is mounted between said middle portion and a
said upper portion of said housing member.
30. A pump as set forth in claim 28, wherein: at least one of said
core, said balloon, said outlet member, said filter member and said
regulator member is mounted between said middle portion and said
lower portion of said housing member.
31. A pump as set forth in claim 28, including: a bolus member
mounted within said middle portion of said housing member.
32. A pump as set forth in claim 28, wherein: said inlet member is
mounted in either said upper portion or said lower portion of said
housing member.
33. A pump as set forth in claim 28, wherein: said upper portion of
said housing member covers an upper side of said middle portion of
said housing member, and said lower portion of said housing covers
a lower side of said middle portion of said housing member.
34. A pump as set forth in claim 33, wherein: said housing member
is constructed of plastic; and said upper portion, said middle
portion and said lower portion of said housing members are fixedly
interconnected by laser welding.
35. A pump as set forth in claim 34, wherein: said middle portion
of said housing member includes embossed channels therein.
36. A pump as set forth in claim 35, wherein: said housing member
has a generally flat shape.
37. A pump as set forth in claim 18, wherein: said housing member
has a sealed construction, such that at least said inlet member,
said outlet member and said flow regulator member cannot be removed
from said housing member without destroying said pump.
38. A pump as set forth in claim 18, wherein: said inlet member
comprises one of either a Luer lock valve or a Luer lock
attachment; and said outlet member comprises the other of said Luer
lock valve and said Luer lock attachment.
39. A pump as set forth in claim 18, including: a core member
mounted in said housing member and including a channel therethrough
for delivery and dispensing of the liquid into and out of said
elastic member; and wherein said elastic member comprises a balloon
having an open end portion thereof sealingly mounted on said
core.
40. A pump as set forth in claim 18, wherein: said flow regulator
member comprises a pressure control valve.
41. A pump as set forth in claim 18, wherein: said flow regulator
member comprises a glass capillary or meander chip.
42. A pump as set forth in claim 18, including: a filter member
mounted within said housing member and disposed upstream of said
flow regulator member.
43. A pump as set forth in claim 18, wherein: said housing member
includes a middle portion, an upper portion and a lower
portion.
44. A pump as set forth in claim 43, wherein: at least one of said
core, said balloon, said outlet member, said filter member and said
flow regulator member has at least a portion thereof mounted in
said middle portion of said housing member.
45. A pump as set forth in claim 44, wherein: at least one of said
core, said balloon, said outlet member, said filter member and said
flow regulator member is mounted between said middle portion and a
said upper portion of said housing member.
46. A pump as set forth in claim 44, wherein: at least one of said
core, said balloon, said outlet member, said filter member and said
regulator member is mounted between said middle portion and said
lower portion of said housing member.
47. A pump as set forth in claim 18, wherein: said housing member
includes a cap detachably connected with said housing member, and
enclosing said balloon and said core therein.
48. A pump as set forth in claim 18, including: a bolus member
mounted within said housing member.
49. A pump as set forth in claim 18, wherein: said housing member
is constructed of plastic; and said housing member includes upper,
middle and lower portions which are fixedly interconnected by laser
welding.
50. A pump as set forth in claim 18, wherein: said housing member
includes a middle portion with embossed channels formed
therein.
51. A pump as set forth in claim 18, wherein: said housing member
has a generally flat shape.
Description
FIELD OF THE INVENTION
[0001] The invention relates to a mechanically operated liquid
pump, particularly for medical or nutrient liquids, and for liquids
in the biological and laboratory sector.
BACKGROUND OF THE INVENTION
[0002] Many different types of liquid pumps are used for delivering
medical, nutrient or biological liquids, or liquids in the
laboratory sector. For example, pumps are known that are operated
by electric energy, electrochemically, by gas, mechanically,
electromechanically, and by physical mechanics. Many of these pumps
can generally only be used after quite a long start-up time and
often provide the user and consumer with insufficient dosing
precision. The known pump systems are also very expensive and are
not very satisfactory from the environmental point of view. They
often cannot be used portably by the user.
[0003] Mechanically operated liquid pumps are characterized by a
drive mechanism, which can generally be of quite simple
configuration. Thus, various designs have been disclosed in which
expandable elastic elements are used to store and dispense the
liquid.
[0004] A mechanically operated liquid pump, particularly for
medical or nutrient liquids, is known from EP 0 944 405 B1. It has
a housing designed as a tube. The housing accommodates an
expandable elastic element that is used to store and dispense the
liquid and that is designed as a hose. The latter has openings in
the area of its ends. A conduit for delivering liquid to the hose
is connected to the hose in the area of one opening. A further
conduit that serves to discharge the liquid out of the hose is
connected to the latter in the area of the other opening. This
conduit is routed out of the housing. The end of the conduit
directed away from the hose is provided with a device for
restricting the volumetric flow of liquid dispensed from the
elastic element.
[0005] A mechanically operated liquid pump, particularly for
medical and nutrient liquids, is known from DE 100 58 121 A1. It
comprises a bag for receiving the liquid, and a dispensing conduit
for the liquid. The bag is placed into a housing. The housing has a
first housing part with hinges at both ends for receiving a second
housing part and also a closure lid for the second housing part.
Both housing parts are assigned a device for exerting a compressive
force on the bag for the purpose of dispensing the liquid from the
latter. This device comprises an elastic element for acting on one
side of the bag, and the second housing part for acting on the
opposite side of the bag. The bag used in the pump, or the pump
itself, can be used just once or can be reused several times.
Depending on the chosen elasticity of the elastic element,
different flow rates and emptying times are possible for the pump.
The elastic element is designed such that the liquid is pressed out
of the bag until the elastic element bears on the second housing
part for acting on the opposite side of the bag, and the bag is
emptied in this state.
[0006] EP 1 321 156 A1 describes a valve, particularly for medical
and nutrient liquids. This valve allows the flow of liquid passing
through the valve to be kept substantially constant. A component
part of the valve is formed by a valve body that has the function
of an active regulating element, the function of which depends on
the liquid pressure acting in a chamber of the valve. If the
pressure in the liquid chamber increases, this leads to an
adjustment movement of the valve body, which movement throttles the
discharge of the liquid from the inlet channel of the valve,
whereas a decrease of the liquid pressure in the chamber has the
effect that the valve body executes a movement that reduces the
throttling of the liquid emerging from the inlet channel. A flow
restrictor is fitted in the outflow parts of the valve. By choosing
different flow restrictors, and replacing one flow restrictor with
another flow restrictor, it is possible to set various constant
flow rates of the valve.
[0007] EP 0 424 494 B1 describes a device for dispensing a fluid to
an outlet, the fluid being in particular a medical liquid. This
liquid is delivered to a hose from an expandable elastic element
for storing and dispensing the liquid, which hose establishes the
connection to a cannula on the patient side. The hose is assigned a
device for restricting the volumetric flow of liquid dispensed from
the elastic element. This conduit forms the main conduit. A side
conduit branches off upstream of the restrictor device and opens
back into the main conduit downstream of the restrictor device. The
side conduit is provided with a bolus dose device.
[0008] A common feature of all the devices mentioned above is that
they have only some of the functional parts necessary for a
mechanically operated liquid pump. This means that they have to be
combined with other required functional parts. This combination is
provided in the form of separate units, which accordingly have to
be connected to one another for use. This means complicated
handling, especially if medical or nutrient liquids are to be
administered, and, in addition, there is considerable danger of the
functional parts being mixed up or incorrectly connected. There is
therefore a considerable danger of incorrect operation of a system
made up of individual functional parts and intended to function as
a mechanically operated liquid pump.
SUMMARY OF THE INVENTION
[0009] The object of the present invention is to make available a
mechanically operated liquid pump, particularly for medical or
nutrient liquids, in which all the functional parts required for
the function of the liquid pump are accommodated in one unit that
is of a particularly compact design, this arrangement of the
functional parts being intended to ensure that incorrect operation
of the pump is ruled out and, accordingly, when the pump is used in
the field of medicine, that it simply has to be connected to the
patient.
[0010] The object is achieved by a mechanically operated liquid
pump, particularly for medical or nutrient liquids, and for liquids
in the biological and laboratory sector, with the following
functional parts mounted inside a housing of the liquid pump:
[0011] a closeable inlet for delivery of the liquid, [0012] an
expandable elastic element for storing and dispensing the liquid
delivered via the closeable inlet, [0013] a device for maintaining
substantially constant and/or restricting the volumetric flow of
liquid dispensed from the elastic element, [0014] an outlet leading
out of the housing.
[0015] Therefore, according to the invention, all the functional
parts important for the function of the liquid pump are arranged
inside the housing of the liquid pump. Accordingly, to start the
liquid pump up, all that need be done is to deliver the liquid
through the closeable inlet and connect the outlet from the housing
to the element that further conveys the liquid dispensed from the
pump, for example via a Luer lock attachment to a hose, the end of
which directed away from the attachment is connected to a catheter,
which can be connected to the patient. The outlet is therefore
provided in this case for connection to a device that can be
connected to the patient.
[0016] It will therefore be appreciated that the liquid pump is
simple to operate. Incorrect operation is ruled out, and, in the
case of the pump being used in the field of medicine, all that has
to be done is to connect the patient. By virtue of the
configuration of the liquid pump according to the invention, with
the functional parts mounted inside the housing, it is possible for
the pump to have a small and compact design.
[0017] It is considered particularly advantageous if the functional
parts are calibrated. The functional parts are thus adapted to one
another in terms of their physical behavior, such that a
substantially constant volumetric flow of liquid is dispensed from
the pump, independently of the pressure in the expandable elastic
element.
[0018] Advantageously, the housing, at least in an area having the
inlet, the outlet and the device for maintaining substantially
constant and/or restricting the volumetric flow of liquid dispensed
from the elastic element, cannot be dismantled without destroying
it, and, in particular, the entire housing cannot be dismantled
without destroying it. Accordingly, if the housing is intact, i.e.
not destroyed, as a whole or in the area of the aforementioned
functional parts, this provides the person using the pump with an
assurance that the pump has not been tampered with.
[0019] The inlet and/or the outlet are preferably designed as Luer
lock valve or Luer lock attachment. These are therefore
standardized valves and attachments, which permit uncomplicated
delivery and discharge of the liquid.
[0020] According to a preferred embodiment of the invention, the
expandable elastic element is designed as a balloon provided with
an opening, the balloon being mounted sealingly in a core mounted
in the housing, and at least one channel for delivery and
dispensing of the liquid into the balloon and from the balloon
extends through the core. It is therefore an elastic element
provided with a single opening, in contrast to a hose with two
openings. Accordingly, this opening serves both as an inlet for the
liquid and also as an outlet for the liquid. The balloon preferably
bears in a relatively unstressed state on the core. This is to be
understood as meaning that the balloon can bear with a certain
pretensioning on the core, since complete emptying of the balloon
is to be sought. The balloon is fastened and sealed exclusively in
the area of its end that has the opening. This is preferably done
directly on the core. The balloon can in principle be made of any
material having the necessary elasticity for storing and dispensing
the liquid. Silicone is regarded as the preferred material. The
balloon is intended to have a capacity of 10 ml to 150 ml in
particular.
[0021] In the liquid pump, it is considered particularly important
for it to have a relatively flat design, since it is generally worn
by a patient directly on the body. To achieve an expansion of the
balloon preferably in its direction of width and less so in the
direction of its height, provision is made that, in a first
direction of extent perpendicular to the longitudinal axis of the
core, the balloon has relatively thick wall portions, and, in a
second direction of extent perpendicular to the longitudinal axis
of the core and perpendicular to the first direction of extent, it
has relatively thin wall portions. This means that the balloon
deforms more strongly in the area of the thin wall portions, with
the result that, upon expansion of the element, a cross-sectional
configuration approximating substantially to the shape of an
ellipse is obtained. The balloon is produced in particular by
injection molding.
[0022] According to a preferred embodiment of the invention,
provision is further made that the device for restricting the
volumetric flow of liquid dispensed from the elastic element is
designed as a valve, in particular as a pressure control valve. The
device for maintaining substantially constant the volumetric flow
of liquid dispensed from the elastic element is preferably designed
as a flow restrictor, in particular as a glass capillary or meander
chip. A filter element for the liquid is arranged inside the
housing, in particular upstream of the device for maintaining
substantially constant the volumetric flow of liquid dispensed from
the elastic element.
[0023] The housing is advantageously made up of several parts. It
has in particular a middle part, an upper part and a lower part,
the terms upper part and lower part having been chosen simply to
distinguish these two parts relative to the middle part. Since the
pump can be oriented in any desired way, the upper part can be the
lower part and the lower part the upper part.
[0024] In view of the fact that the housing is made up of several
parts, it is possible to assign defined functions to the individual
parts of the housing and to the planes dividing the individual
parts of the housing, for example the space between middle part and
upper part. Thus, the housing preferably has a cap which can be
connected to the upper part and to the lower part, in particular
clipped non-releasably thereto, for arrangement of the balloon and
of the core inside the cap. The core for the balloon and/or the
outlet and/or the filter element and/or the device for restricting
the volumetric flow of liquid dispensed from the elastic element
is/are mounted in the middle part and in the upper part or lower
part, between the middle part and the upper part or lower part. The
device for restricting the volumetric flow of liquid dispensed from
the elastic element and/or a bolus device is advantageously mounted
in the middle part. The inlet is preferably mounted in the upper
part or lower part. In order to cover the functional parts which,
in the direction away from the middle part, can protrude past the
upper part and/or lower part, a housing upper part is provided for
covering the upper part, and a housing lower part is provided for
covering the lower part.
[0025] The individual parts of the housing are preferably made of
plastic. This allows the parts to be produced in virtually any
desired shape, inexpensively and with low weight. Parts are
connected to one another in particular by laser welding.
[0026] A particular function is played by the middle part of the
housing. Thus, said middle part not only serves to receive
functional parts, but also has the flow connections between the
functional parts, said connections being formed in particular as
channels embossed in the middle part. These channels are covered by
connecting the middle part to the upper part and lower part, and a
leaktight sealing of the channels between middle part and upper
part or lower part is achieved in particular by laser welding.
[0027] As has been mentioned above, a particularly important aspect
of the pump is considered to be that said pump or the housing is
designed relatively flat. In the area of the balloon, this is
achieved by the special configuration of the balloon and by the
design of the housing as a cap. The rest of the housing is also
designed flat and accommodates the functional parts arranged
therein adjacent to one another, on different planes, on the one
hand in the area of middle part and upper part and on the other
hand in the area of middle part and lower part.
[0028] The mechanically operated liquid pump according to the
invention thus integrates all the functional parts needed for
perfect functioning of the liquid pump and is therefore
advantageous in the following respects: [0029] an integrated
solution through omission of an external hose system between pump,
volumetric flow restrictor and optionally present bolus reservoir,
[0030] an integrated system for delivery of liquid to the
individual components through channels embossed in the middle part,
[0031] an integrated pump solution using a balloon that interacts
with a core, [0032] an integrated capillary/meander protection
filter, [0033] an integrated volumetric flow restrictor in the form
of a capillary or meander chip, [0034] an optional bolus solution,
which can be arranged in series or as bypass, [0035] an integrated
automatic pressure control valve for constant flow rate.
[0036] Further features of the invention are set forth in the
dependent claims, in the description of the figures, and in the
figures themselves. It will be noted that all the individual
features and all combinations of the individual features are part
of the invention.
[0037] The invention is depicted in the figures on the basis of a
mechanically operated liquid pump that is provided with the valve,
without being limited to this illustrative embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] FIG. 1 shows an exploded view of a mechanically operated
liquid pump using the valve according to the invention,
[0039] FIG. 2 shows a vertical longitudinal midsection through the
pump shown in FIG. 1, in particular to illustrate the drive
mechanism of the pump, with a balloon bearing on a core,
[0040] FIG. 3 shows a section according to FIG. 2, with the balloon
filled with liquid,
[0041] FIG. 4 shows a vertical longitudinal section through the
pump shown in FIG. 1, at a distance from the longitudinal center
axis of the pump, in the area of a valve of the pump,
[0042] FIG. 5 shows a section, cut transversely through the pump
illustrated in FIG. 1, in the area of the valve,
[0043] FIG. 6 shows a horizontal longitudinal midsection through
the pump shown in FIG. 1, with the balloon bearing on the core,
[0044] FIG. 7 shows a section according to FIG. 6, with the balloon
filled with liquid,
[0045] FIG. 8 shows a section through the pump, cut transversely in
the area where the core is supported,
[0046] FIG. 9 shows a section through the pump, cut transversely in
the area of the unsupported portion of the core and of the
liquid-filled balloon,
[0047] FIG. 10 shows an enlarged sectional view of core, balloon
and clamping ring for connection of balloon and core, with the
balloon bearing on the core,
[0048] FIG. 11 shows a section, cut transversely to the
longitudinal extent of the core, through the core and the balloon,
with the balloon bearing on the core,
[0049] FIG. 12 shows a sectional view according to FIG. 11 for a
modified cross-sectional configuration of the balloon,
[0050] FIG. 13 shows an enlarged sectional view of the valve shown
in FIG. 4,
[0051] FIG. 14 shows a diagram illustrating the operating principle
of the mechanically operated liquid pump, and indicating physical
parameters,
[0052] FIG. 15 shows a diagram illustrating the basic arrangement
of the bolus implementation that can be used in the pump, in a
serial circuit,
[0053] FIG. 16 shows a diagram according to FIG. 15 for arrangement
of the bolus implementation in a bypass circuit, and
[0054] FIG. 17 shows a cross-sectional view of bolus implementation
used in a pump according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0055] For purposes of description herein, the terms "upper",
"lower", "right", "left", "rear", "front", "vertical", "horizontal"
and derivatives thereof shall relate to the invention as oriented
in FIG. 1. However, it is to be understood that the invention may
assume various alternative orientations and step sequences, except
where expressly specified to the contrary. It is also to be
understood that the specific devices and processes illustrated in
the attached drawings, and described in the following
specification, are simply exemplary embodiments of the inventive
concepts defined in the appended claims. Hence, specific dimensions
and other physical characteristics relating to the embodiments
disclosed herein are not to be considered as limiting, unless the
claims expressly state otherwise.
[0056] The mechanically operated liquid pump 1 illustrated in FIG.
1 is used in particular for administering medical or nutrient
liquids, for example for administering a liquid medicament.
[0057] The pump 1 has a multi-component housing 2 formed by a
middle part 3, by an upper part 4 and a lower part 5 that interact
with said middle part 3, by an upper shell 6 interacting with the
upper part, and by a lower shell 7 interacting with the lower part
5.
[0058] The middle part 3 is provided on its upper face with a
recess 8 that is open to the free edge of the middle part 3 and
that has a semicircular cross section, and the upper part 4 is
provided on its lower face, and in the corresponding edge area,
with a corresponding semicircular recess 9. With the upper part 4
connected to the middle part 3, the two recesses 8 and 9 form a
circular cross section for receiving a conically widened end area
10 of a core 11. Except at its end area 10, the core 11 has a
constant external diameter. This cylindrical portion of the core 11
is designated by reference number 12. A channel 13 (see FIG. 2)
extends through the core 11 in its longitudinal center axis, and
several channels 14 extending radially through the core 11 branch
off from the channel 13 in the area of the portion 12 (FIG. 6). In
the area of the outer circumference of the core 10, the radial
channels 14 open into circumferential grooves 15 of the core
11.
[0059] An elastic element interacts with the core 11 and is
designed as a silicone balloon 16. The latter is produced by
injection molding. The balloon has a conically widened end area 17
with opening 17a, corresponding to the end area 10 of the core 11,
and it has a portion 18 which corresponds to the outer shape of the
portion 12 of the core 11 and which merges into the end area 19,
closed on account of the balloon design and remote from the end
area 17.
[0060] The dimensions of core 11 and balloon 16 are such that, as
can be seen from FIG. 2, the balloon fitted onto the core 11 bears
completely on the core 11, such that the end area 17 of the balloon
contacts the end area 10 of the core, and the portion 18 of the
balloon 16 contacts the portion 12 of the core 11, and, finally,
the end area 19 of the balloon 16 bears on the free end of the core
11. The dimensions of the balloon 16 in relation to the core 11 are
chosen here such that the balloon 16 bears on the core 11 with
relatively little pretensioning, in other words in a relatively
unstressed state.
[0061] In order to fasten the end area 17 of the balloon 16 on the
core 11, at the end area 10 of the latter, a clamping ring 20 is
provided, which is fitted externally onto the balloon 16 at the end
area 17 thereof. The structure thus formed is inserted with the
clamping ring 20 into the recess 8 of the middle part 3, and the
upper part 4 is then connected to the middle part 3, as a result of
which the clamping ring 20 and therefore the core 11 and balloon 16
are held secure in the recesses 8 and 9 of middle part 3 and upper
part 4. For the clamping ring 20, the recesses 8 and 9 have a seat
that widens conically in the direction away from the respective
free edge of the middle part 3 and upper part 4, in order to ensure
a secure hold of the clamping ring 20.
[0062] The middle part 3, the upper part 4 and the lower part 5
serve to receive further operating elements of the pump 1:
[0063] A Luer check valve or lock valve 21 connected to the upper
part 4 passes through an opening 22 in the upper part 4, and, as is
explained in the following description of FIG. 2, has a Luer lock
valve housing 23 and a Luer lock valve core 24. By way of a channel
25, the Luer lock valve 21 is in communication with a channel 26,
which is formed between the upper part 4 and the middle part 3 and
which communicates with the channel 13 extending through the core
11.
[0064] The pump is filled with liquid by way of the Luer lock valve
21 and the channels 25, 26 and 13. Starting from the unfilled state
shown in FIG. 2, and with increasing delivery of liquid, the
balloon 16 expands in that area not clamped by the clamping ring
20, and, when completely filled, adopts the final shape illustrated
in FIG. 3. The space occupied by the liquid is designated there by
reference number 27. It will be seen from FIGS. 2, 3 and 6 to 12
that, as it fills with liquid, starting from its initial state
bearing on the core 11, the balloon 16 changes shape both in the
longitudinal direction of the core and also in transverse
directions thereof, i.e. in a first transverse direction and in a
second transverse direction perpendicular thereto.
[0065] The upper part 4 and the lower part 5 are provided with
locking projections 28, which serve to receive a cap 29 that is
approximately kidney-shaped in cross section. As can be seen from
FIG. 9, this cap has an extension in its direction of width that is
substantially greater than that in the direction of its height. The
width to height ratio is 2:1, for example. As can be seen from FIG.
2 for example, the length to height ratio of the cap 29 is
approximately 2.5:1. The cap 29 is preferably clipped
non-releasably onto the housing 2. When the balloon 16 is filled
completely with liquid, it takes up as much as possible of the
internal space in the cap 29.
[0066] This is achieved by the fact that, as can be seen from the
view in FIG. 11 showing the balloon 16 bearing on the core 11, the
balloon 16 has relatively thick wall portions 30 in a first
direction of extent X perpendicular to the longitudinal axis of the
core 11, and it has relatively thin wall portions 31 in a second
direction of extent Y perpendicular to the longitudinal axis of the
core 11 and perpendicular to the first direction of extent X. Thus,
when liquid is introduced into its space 27, the balloon 16 seeks
to expand preferably in the direction of extent X, thereby
resulting in the expanded oval cross-sectional shape illustrated in
the view in FIG. 9. Overall, the pump 1 is presented as a flat
functional component that can be easily worn on the body, and the
balloon 16, in the state when filled with liquid, likewise adopts a
flat shape adapted to the outer contour of the pump 1.
[0067] The channels 26 and 13 serve not only to deliver the liquid
from the Luer lock valve 21 into the balloon 16, but also to
dispense the liquid from the interior of the balloon 16 to the
patient. Thus, the channel 26 is continued past the inlet point of
the channel 25 to a valve 32 that is mounted in the middle part 3
and upper part 4 and that restricts the volumetric flow of liquid
discharged from the balloon 16. This valve 32 is formed by an
elastic valve membrane 33 held at the edge between middle part 3
and upper part 4, by a valve core 34 that interacts with the valve
membrane 33, by a compression spring 35 supported on the valve
membrane 33 and the upper part 4, and by an adjusting screw 36,
which is mounted in a thread of the upper part 4 and can be brought
into operative connection with the valve membrane 33.
[0068] As can be seen from the detailed view in FIG. 13, the
channel 26 opens into a radially extending channel 37 of the valve
membrane 33 and from there into a radial channel 38 of the valve
body 34, which opens into an axial channel 39 of the valve core 34.
This channel 39 is open in the area of its end directed toward a
reinforced portion 40 of the valve membrane 33. A stop designed as
an adjusting screw 36 is arranged on that side of the portion 40
directed away from the channel 39, which portion 40 has the
function of a closure element. In principle, this stop could also
be stationary. Between the projections 41 of the valve membrane 33,
the valve core 34 is held so as to be axially immovable relative to
the valve membrane 33 and also non-rotatable relative to the
latter.
[0069] The valve 32 is used to stop the volumetric flow in the
event of too high a pressure. Two separate chambers 42 and 43 are
formed in the valve and are connected to each other via a channel
44, which extends through the valve core 34 and is arranged
parallel to the channel 40. The chamber 42, which lies in the
direction of flow to the inlet, and therefore to the channel 26,
serves as a blocking chamber. The chamber 43 lies in the direction
of flow to the outlet 45. To filter the liquid dispensed through
the valve 32, a filter 46 is provided which is clamped at the edge
between the middle part 3 and the lower part 5. Starting from the
chamber 43 and the outlet 45, the liquid passes to a channel 47
(FIG. 5) in flow communication with the outlet 45, and from there
to a Luer lock attachment 48 held between the middle part 3 and the
lower part 5. A Luer lock connector 49, provided with a hose 50
leading to the patient, can be connected to the Luer lock
attachment 48.
[0070] As can be seen from the view in FIG. 5, a glass capillary 53
is fitted into the channel 47. This glass capillary constitutes a
flow restrictor, which is able to restrict the volumetric flow
passing through the channel 47 out of the pump, since the flow
restrictor has a smaller cross section than the channel 37 lying in
the inlet. By selecting various flow restrictors, it is possible to
set various constant flow rates, as long as the pressure at the
inlet does not drop below a defined value. In principle, the
cross-sectional area of flow of the inlet is greater than the
cross-sectional area of flow of the outlet. Of course, the flow
restrictor can be designed other than in the form of a glass
capillary. For example, it is entirely conceivable to provide
downstream of the valve, in the outlet of the pump, a meander chip
that restricts the through-flow.
[0071] Because of the stated diameters of the channels that connect
the space 27 of the balloon to the valve 32, and the diameter of
the channels arranged behind the valve 32 with the flow restrictor
53, the resistance that the channel 47 with flow restrictor 53 sets
against the outflow of liquid from the housing 2 is greater than
the resistance made to the liquid flowing into the valve 32.
[0072] In an initial state, the valve membrane 33 is located in the
position shown in FIG. 13, in which the valve membrane 33 bears
largely on the middle part 33, without requiring any action of the
compression spring 35. Because of the positioning of the valve core
34 relative to the portion 40 of the valve membrane 33, a small gap
is provided between the portion 40 and an encircling and therefore
annular projection 54 of the valve core 34. This projection 54
encloses the channel 43. Accordingly, liquid flows through the
channel 13 of the core 11 and through the adjoining housing channel
26 into the channel 37 of the valve membrane 33 and from there into
the channels 38 and 39 of the valve core 34. From the channel 39 of
the valve core 34, the liquid flows through the gap formed between
the projection 54 and the portion 40 of the valve membrane 33, and
into the chamber 42 located there, and from the chamber 42 through
the channel 44 between valve membrane 33 and valve core 34 to the
chamber 43, passes the filter 46 and travels through the outlet 45
to the channel 47 with the flow restrictor 53. If a higher liquid
pressure is established in the inlet, thus also in the channel 39,
without a greater volumetric flow being able to issue from the pump
as a result of the flow restrictor 43, this has the result that the
valve membrane 33, which is clamped in the edge area between the
middle part 3 and the upper part 4, deforms in the central area in
the direction of the adjusting screw 36 with the stop function,
specifically counter to the force of the compression spring 35.
When the valve membrane 34 with its portion 40 comes up against the
projection 55 of the adjusting screw 36 directed toward the portion
40, the portion 40 makes contact there with the adjusting screw 36,
such that, since the valve membrane 33 cannot move any farther up
in the direction of the upper shell, the portion 40 is pressed
against the projection 54 of the valve core 34 and thus closes the
flow through the channel 39. As the liquid flows out through the
flow restrictor 53, the pressure in the chamber 43 decreases, with
the result that the membrane, by virtue of its own elasticity,
moves back again in the direction of its initial state according to
FIG. 13, such that the portion 40 disengages from its contact with
the adjusting screw 36, and the flow gap between the projection 54
and the portion 40 is again freed. Depending on the pressure
prevailing in the balloon 16, this state can be obtained only when
the initial position of the valve membrane 33 is reached, as shown
in FIG. 13, or even earlier, in other words with the valve membrane
33 still deflected. The adjusting screw 36 serves to modify the
opening and closing behavior of the valve 32. The further the screw
frees the adjustment path of the valve membrane, the greater is the
secondary pressure in the valve. In principle, it is not necessary
to provide the compression spring 35. It is of advantage when
greater pressures are intended to be dealt with by the pump 1 and,
accordingly, the elastic restoring behavior of the valve membrane
33 is not sufficient to move it into the initial position according
to FIG. 13.
[0073] With the valve 32, the volumetric flow of liquid is
therefore restricted as a function of the pressure prevailing in
the balloon 16, and the volumetric flow of liquid is maintained
substantially constant via the flow restrictor 53. In principle,
the liquid pump could be modified by providing only a device for
maintaining substantially constant the volumetric flow of liquid
dispensed from the elastic element, or only a device for
restricting the volumetric flow of liquid dispensed from the
elastic element.
[0074] Before using the mechanically operated liquid pump, liquid
is delivered through the Luer lock valve 21, as a result of which
the liquid passes into the balloon 16, and the filling level of the
balloon can be read off through the transparent cap 29 on the basis
of the markings 51 which are arranged in the transverse direction
of the cap and which are a reference for the transverse expansion
of the balloon as a function of its state of filling. After the
pump 1 has been filled and the pump has been attached to the
patient via the hose 50, liquid is dispensed out of the pump
through the valve 32, with elastic pretensioning of the expanded
balloon 16, and this is done until the balloon has been completely
emptied and bears on the core 11.
[0075] The particularly simple design of the described liquid pump
allows it to be used in a variety of different ways. The user is
able to operate the pump anywhere, and immediately, without long
start-up times. It can be used carried around by the user, or used
in one place, specifically in all normal life situations in or
outside the field of medicine. The pump can be used in a sterile
state and requires minimal operating/handling effort. Because of
the simple construction of the small number of component parts, the
pump is inexpensive to produce. This is a condition for its being
able to be used particularly in outpatient care, and in financially
weak markets. The low weight of the pump permits its use in
accident and emergency situations, in field hospitals and in
disaster areas. Some or all of the functional elements of the pump
are exchangeable. The pump is suitable for short or long dispensing
times, for example, in the case of a balloon with a capacity of 25
ml, for a flow rate of 2.5 ml per hour, that is to say a running
time of 10 hours. It is of course possible to use other balloons
with other volumes, for example 10 ml, 50 ml, 100 ml or 150 ml. The
running time can be much longer, for example up to 24 hours.
Although flow rates of >1000 ml per hour are entirely possible,
a flow rate of 0.5 to 10 ml per hour is considered the preferred
option.
[0076] According to the illustrative embodiment, a balloon is
described which is produced by injection molding and serves as a
container for the medicament solution and as a pressure reservoir.
The balloon has a defined contour in cross section and in
expansion, for filling flat housing spaces and for avoiding
pressure peaks. It is radially and/or axially pretensioned on a
one-part or multi-part core, in order to increase the restoring
forces. One end of the balloon is sealed off in an airtight manner
over the core and fixed in position by a clamping ring with a form
fit. The balloon is freely movable in the axial and radial
directions during filling and emptying, being elastically
deformable and able to move in a manner free from friction inside
the cap.
[0077] The pump 1 can additionally be provided with a bolus
reservoir. In FIG. 1, the provision of such a bolus is indicated by
reference number 52. The pump can be converted to this extent, as
and when required.
[0078] FIG. 14 is a diagram illustrating how the above-described
mechanically operated pump works and showing the physical
parameters. The contour of the pump is indicated by the
dot-and-dash line.
[0079] FIG. 15, relating to the bolus implementation, shows the
bolus reservoir BR downstream of the capillary K, and thus
downstream of the device for maintaining substantially constant the
volumetric flow of liquid dispensed from the elastic element
BK.
[0080] The conduit leading to the capillary K is designated by ZF,
and the conduit leading away from the bolus reservoir is designated
by AF. In contrast to the serial circuit of capillary K and bolus
reservoir BR shown in FIG. 15, these are shown in a parallel
circuit in FIG. 16.
[0081] FIG. 17 illustrates the configuration of the bolus reservoir
in place of the bolus arrangement designated by reference number 52
in FIG. 1. In a serial circuit in the sense of the illustration in
FIG. 15, the channel 47 downstream of the capillary 53 (FIG. 5)
opens into a bolus chamber 56, which is designed as a depression in
the lower part 5 and which is sealed off from a recess 58 in the
middle part 3 by means of an elastic membrane 57 clamped between
the middle part 3 and the lower part 5 in the edge area. The recess
58 serves to receive a ram 59, which is displaceable toward the
membrane 57 in the direction of the arrow F counter to the
restoring force of an elastic silicone ring 60, such that it moves
the membrane 57 into the bolus chamber 56, as a result of which
liquid abruptly issues from the bolus chamber 56 to the outlet of
the pump and thus to the Luer lock attachment 48. As soon as there
is no longer any pressure being exerted on the ram 59 from outside,
the force of the elastic silicone ring 60 causes the ram 59 to
return to its initial position shown in FIG. 17, in which the
volume of the bolus chamber 56 is increased again and the ram 59
bears with a projection on the upper part 4 and also extends
through a passage 61 in the upper part 4. Instead of the elastic
silicone ring, it is also possible, for example, to provide a
compression spring that surrounds the ram 59 and has the task of
transferring the latter to its position freeing the bolus chamber
56, as is illustrated in FIG. 17.
[0082] Therefore, by means of the bolus device, a discrete
administration of dosed individual quantities of medicament
solutions is made possible.
[0083] In the foregoing description, it will be readily appreciated
by those skilled in the art that modifications may be made to the
invention without departing from the concepts disclosed herein.
Such modifications are to be considered as included in the
following claims, unless these claims by their language expressly
state otherwise.
[0084] The invention claimed is as follows.
* * * * *