RU133421U1 - SLIDING CORE DEVICE FOR FLUID SUPPLY - Google Patents

Abstract

1. A fluid supply pump, comprising: a support core configured to longitudinally extend and contract along the pump axis; a limiter configured to limit the longitudinal extension of the support core to a predetermined maximum length; and - an expandable elastic balloon attached to the support core in at least one place and designed to receive fluid. A pump according to claim 1, further comprising a shell surrounding the elastic balloon and at least a portion of the support core. The pump according to claim 2, in which the shell has such a size and shape that, when the elastic balloon is filled with fluid, the elastic balloon has a size and position that are independent of the size and shape of the shell. The pump according to claim 2, in which the shell is of such size and extent that when the elastic balloon is filled with fluid, there is a gap between the outer surface of the elastic balloon and the inner surface of the shell. A pump according to claim 1, wherein the elastic balloon is made of silicone. The pump according to claim 1, in which the supporting core comprises a first part and a second part made for longitudinal sliding relative to each other. The pump of claim 6, further comprising a connector for connecting the first part and the second part. A pump according to claim 1, wherein the limiter comprises a ball bearing located in the channel. The pump of claim 8, wherein the channel length is determined based on a predetermined maximum length of the support core. The pump according to claim 1, in which the supporting core is made for longitudinal elongation when the fluid enters

Description

Utility Model Area

This utility model relates to a fluid supply device.

Prerequisites for creating a utility model

Elastomeric pumps are widely used in medicine for supplying fluids and medicines to a patient. Some fluid pumps are stored in a drug reservoir or an elastic balloon made of silicone or another rubber-like polymer.

US 5,284,481 describes an infusion pump with a central core of constant length with an expanding elastic balloon attached to it to receive the current medium. An elastic balloon is attached to the central support core (also referred to below for brevity as the "core") of constant length in positions along the shaft, which are separated by an unchanged gap. When filled, the elastic balloon expands, and the increased surface area of the elastic balloon stores energy that exerts pressure on the fluid, displacing the fluid from the elastic balloon. The flow rate of the fluid is often limited by a restriction diaphragm, such as a glass capillary or a piece of polyvinyl chloride tube.

1, a typical flow profile 18 (i.e., flow rate versus time) for a standard elastomeric pump indicates that the flow rate of the fluid from the pump is not constant during the flow of fluid. The flow begins with a strong initial burst 20, continues with phase 21 in the form of a ditch having a lower flow rate, and ends with a small second burst 22. While dips and bursts of such a profile can be averaged to provide a sufficient flow rate, in some cases, such as the administration of toxic drugs or when a narrow therapeutic dose is required, an initial surge may lead to an overdose or other undesirable situation.

The initial surge 20 is generated by significant forces acting on the fluid from the expanded elastic balloon. To reduce the initial burst in flow rate, a filled pump can be stopped for a period of time before starting to supply a fluid in order to allow the elastic balloon to lose some of its elasticity, thereby reducing the force exerted on the fluid.

Phase 21 in the form of a dip is the result of a combination of two phenomena. As the fluid exits the elastic balloon, the elastic balloon is compressed and the energy stored in the elastic balloon is reduced. Thus, the pressure exerted by the elastic balloon on the fluid decreases, resulting in a decrease in flow rate. However, at the same time, the physical contraction of the elastic balloon leads to an increase in the wall thickness of the elastic balloon, which causes the elastic balloon to exert greater pressure on the fluid. In the initial stage, the first effect is predominant. As the elastic balloon is emptied, the second effect gradually becomes more dominant and appears as a second surge 22 at the end of the fluid supply.

If the wall thickness of the elastic balloon is not uniform, then the elastic balloon will expand faster in thin areas upon receipt of the fluid, thereby further enhancing thickness changes. This effect causes the elastic cylinder to take an asymmetric shape, which, in turn, leads to uneven flow rates and inconsistent flow rates among the same pumps. To combat this effect, an elastic balloon is often placed in an outer shell that limits its asymmetric expansion, such as a rigid shell or a flexible and non-expanding shell. In some pumps, an elastic balloon is formed from a rubber-like polymer that exerts a force on the inside of the fluid and a silicone coating inside the elastic balloon that prevents contact of the fluid with the rubber-like polymer.

Short description

In general, a fluid supply pump comprises a core configured to longitudinally extend along the axis of the pump, a limiter configured to limit longitudinal extension of the core to a predetermined maximum length, and an expandable elastic balloon attached to the support core in at least one place and made to receive fluid.

Embodiments may include one or more of the following. The pump comprises a shell enclosing an elastic balloon and at least a portion of the support core. The shell has a size and shape such that when the elastic balloon is filled with fluid, the elastic balloon has a size and position that are largely independent of the size and shape of the membrane. The shell is of such size and extent that there is a gap between the outer surface of the elastic balloon and the inner surface of the membrane when the elastic balloon is filled with fluid. The elastic balloon is made essentially of silicone. The place where the elastic balloon is attached to the core is selected based on at least one of: the volume of the elastic balloon in the filled state and the required flow rate of the fluid supplied from the pump.

The core has a first part and a second part, made so as to longitudinally slide relative to each other. The pump comprises a connector for connecting the first part and the second part. The limiter contains a ball bearing located in the channel. The channel length is determined based on a predetermined maximum core length. The support core is designed for longitudinal elongation when the fluid enters the elastic balloon and longitudinal contraction when the fluid exits the elastic balloon. The pump is designed to supply a fluid with a substantially constant flow rate.

According to another aspect, a method of supplying fluid from a pump includes receiving fluid into an elastic balloon and supplying fluid from a pump. Obtaining fluid in an elastic balloon includes longitudinally extending the support core along the axis of the pump and expanding the elastic balloon. The elongation of the support core is limited to a predetermined maximum length by the limiter. The supply of fluid from the pump includes compressing the elastic balloon and returning the support core along the longitudinal axis of the pump.

Embodiments may include one or more of the following. The fluid supply from the pump includes a substantially constant flow rate. The extension of the supporting core includes longitudinal sliding of the first part of the supporting core relative to the second part of the supporting core. Expanding an elastic balloon includes expanding the elastic balloon to the size and shape of the envelope surrounding the elastic balloon. The flexible balloon is made essentially of silicone.

The pump described above has several advantages. In particular, the implementation of a pump with a sliding core, as stated in claim 1 of the formula of the present utility model, gives an additional degree of displacement to the pump when the elastic balloon is filled or fluid is supplied from the pump. This additional degree of displacement affects the flow profile of the fluid, making the pump capable of delivering fluid with a reduced initial burst or even without an initial burst of flow rate. In addition, the implementation of the pump with a sliding core, as stated in claim 1 of the formula of the present utility model, allows the elastic balloon to expand when filled substantially symmetrically, even if there are slight changes in the wall thickness of the elastic balloon. The material composition of the elastic balloon, being primarily silicone, further contributes to the symmetrical expansion of the walls of the elastic balloon. As a result of this symmetrical expansion, the elastic balloon exerts uniform pressure on the fluid inside it, making it possible to maintain a constant flow rate during the flow of fluid. Thus, a relatively constant flow rate is maintained during the delivery of most of the fluid from the pump. Symmetric expansion of the elastic cylinder also helps to reduce or eliminate the spike in the flow rate at the beginning of the fluid supply from the pump. A constant flow rate is achieved as soon as the pump is filled with fluid. No waiting period is required for the relaxation of the pressure exerted by the elastic balloon on the fluid inside. Additionally, the variability between the different devices is reduced, since the expansion of the elastic balloon and, thus, the pressure applied to the fluid inside it, is the same for similar devices.

Accordingly, the task of obtaining a uniform fluid flow is solved by a combination of features of an independent claim of a utility model. Other features and embodiments of the utility model result from the dependent items and the description of exemplary embodiments together with the figures below.

Brief Description of Drawings

1 shows a flow rate profile for a standard elastomeric pump and a sliding core pump.

Fig. 2A shows a sliding core pump with an essentially empty elastic balloon,

FIG. 2B shows a sliding core pump with a substantially filled elastic balloon.

Figure 3 is a disassembled state of a part of a sliding core pump.

Figa is a side view of a part of the pump with a sliding core in an exploded state.

Fig. 4B is a top view in section of a disassembled part of a sliding core pump.

Figv is a side view in cross section of a part of the pump with a sliding core in an exploded state.

Detailed description

2A, a sliding-core pump delivers fluids, such as antibiotics, painkillers, chemotherapeutic agents, and other medications, to a patient. The pump comprises a generally cylindrical support core 32 carrying an elastic balloon 4 and an outer shell 34. The fluid is stored in an elastic balloon 4 that exerts pressure on the fluid by pumping fluid from the pump through the fluid supply line 10. A patient-related connector 13 (e.g., a Luer adapter) connected to the end of the fluid supply line 10 facilitates the flow of fluid to the patient. In some embodiments, the fluid supply line 10 is connected to other parts, such as an air trap and an antimicrobial filter 9 or a microchannel restriction tube 12, which may be, for example, a glass capillary or a piece of polyvinyl chloride tube. Attached to the fluid supply line 10, the clamp 11 starts and stops the fluid flow from the pump 30.

2A and FIG. 3, the supporting core 32 includes movable or telescopic parts, including a first sliding core part 1 and a second core sliding part 3. The core sliding parts 1 and 3 are held together by an annular connector 2. In another embodiment, the first core sliding part 1 is inserted into the annular cavity in the second core sliding part 3. The elastic balloon 4 is attached to the support core 32 at two locations 8a and 8b, which are selected based on the desired filling volume of the elastic balloon. The first core sliding part 1 and the second core sliding part 3 can be longitudinally extended relative to each other along the axis 8 of the pump 30. This relative movement of the core sliding parts 1 and 3 leads to a longitudinal and concentric expansion of the elastic balloon 4 in an elliptical shape. The relative movement of the sliding parts 1 and 3 of the core causes a relative displacement of the places 8a and 8b, which are separated by a variable distance of 8 s. When the fluid is introduced into the elastic balloon 4, the distance of 8 s increases as the elastic balloon 4 expands and the support core 32 lengthens. When fluid is supplied from the elastic balloon 4, the distance of 8 s decreases as the elastic balloon 4 contracts and the support core 32 shortens. On figa shows the supporting core 32 in its initial position with a small amount of fluid in the elastic balloon 4. According to figb, as the fluid is introduced into the elastic balloon 4 and the sliding part 1 of the core is elongated longitudinally relative to the sliding part 3 of the core The elastic balloon expands to a balloon-like shape.

The relative longitudinal movement of the sliding parts 1 and 3 of the core along axis 8 is limited by ball bearings 5, which are usually made of glass or medical grade polymer. Ball bearings 5 are located in the slots 6 and / or channels or grooves 7 in the sliding parts 1 and 3 of the core. The elongation limit of the supporting core 32 is determined by the length of the slots 6 or channels 7. In the embodiment shown in FIGS. 4A and 4B, two slots 6a and 6b and two channels 7a and 7b are used. In general, the number of ball bearings 5, slots 6, and channels 7 varies depending on the size of the support core 32 and the desired relative displacement between locations 8a and 8b. In other embodiments, the longitudinal movement of the core sliding parts 1 and 3 is limited by a stopper and a guide assembly or other structural member that allows free movement of the core moving parts 1 and 3 along axis 8, while also providing predetermined end points or limits of this movement.

The elastic balloon 4 is made of a flexible membrane, which allows the air trapped in the elastic balloon to slowly disperse through the permeable membrane. In some embodiments, the flexible balloon 4 is made of self-venting material. The flexible balloon material 4 is also compatible with pharmaceutical formulations. For example, the elastic balloon 4 is made of silicone or another rubber-like polymer. In some embodiments, the implementation of the elastic balloon is made primarily of silicone.

2B again, the sheath 34 protects the elastic balloon 4 (for example, against puncturing, abrasion or dirt) and provides a surface for inscribing with variable process data and device identification data, such as lot number, filling volume, flow rates and flow duration. The shell 34 is configured to surround the elastic balloon 4 both in a filled state and in an unfilled state without deformation or any other effect on the overall shape or position of the elastic balloon relative to the support core 32 when expanding and contracting the elastic balloon 4. That is, as the elastic balloon 4 is filled with fluid, the elastic balloon assumes a shape and position that is independent of the size and shape of the sheath 34. In one example, the sheath 34 is vacuum molded so that have an air gap 35 between the inner surface of the shell 38 and the outer surface 36 of bladder 34 in a fully filled condition. The sheath 34 is fixed (for example, using elastic bands, not shown) to maintain the core 32 at positions 40a and 40b. Since the sheath 34 is attached to the supporting core 32 and moves together with the sliding parts 1 and 3 of the core, the ends of the sheath 34 are longitudinally apart from each other as the elastic balloon expands. Shell 34 may be a soft shell, which is made, for example, of polyvinyl chloride. In other examples, the rigid balloon 4 protects the elastic balloon 4. A rigid rigid shell may completely or partially surround the elastic balloon 4 in its fully expanded state without deformation or any other effect on the overall shape or position of the elastic balloon relative to the support core 32 when expanding and compressing the elastic balloon 4.

4, pump 30 has a loading opening 42 at the open end 44 of the supporting core 32 through which fluids are introduced into the elastic balloon 4. The loading opening 42 is compatible with most syringes and other standard loading devices. The one-way anti-siphon valve 46 at the loading opening prevents fluid from escaping from the elastic balloon 4 during and after filling. A hinged cap device 48 is attached to the support core 32 to close the feed opening 42. At the opposite end 49 of the support core 32, the outlet 50 is connected to the fluid supply line 10. Two flow channels 52 and 54 extend inside the support core 32. The flow channel 52 connects the feed opening 42 to the inside of the elastic balloon 4, while the flow channel 54 connects the inside of the elastic balloon 4 to the outlet 50.

The design of the support core 32 with respect to the presence of sliding parts 1 and 3 gives an additional degree of displacement to the pump 30 when filling the elastic balloon and when supplying fluid from the pump. Again, in FIG. 1, this additional degree of displacement gives the sliding core pump 30 a flow profile 24. While the fluid is initially supplied from the pump, the elastic balloon 4 is compressed and the sliding parts 1 and 3 are longitudinally moved inward. Moving the sliding parts 1 and 3 allows the flexible balloon 4 to exert less pressure on the fluid contained therein. The reduced force results in a minimum initial burst 26 at the beginning of the fluid supply.

After the sliding parts 1 and 3 of the core are reduced to their original position (that is, when the sliding parts 1 and 3 of the core are in contact or when the distance of 8 s is minimal), the elastic balloon continues to compress and expel the fluid, however, further reduction of the supporting core not happening. At this point, the flow rate enters phase 28, which is comparable to the flow rate obtained by supplying fluid from a pump without a sliding core. By adjusting the distance of 8 s with respect to the length, wall thickness, geometry and elasticity of the elastic balloon 4 for the sliding core pump 30, an approximately flat flow velocity profile can be achieved.

In some embodiments, various fluid delivery modes are available, including continuous flow, continuous bolus flow, bolus flow, or variable flow.

A method of supplying fluid from a pump may include:

- obtaining a fluid in an elastic container, including:

longitudinal elongation of the support core along the axis of the pump, and

elastic balloon expansion,

elongation of the support core, limited to a predetermined maximum length limiter; and

- the supply of fluid from the pump, including:

elastic balloon compression, and

contraction of the support core along the longitudinal axis of the pump.

The fluid supply from the pump may include delivering a fluid at a substantially constant flow rate.

The extension of the support core may include longitudinal sliding of the first part of the support core relative to the second part of the support core.

The expansion of the elastic balloon may include expanding the elastic balloon to a shape and position that are substantially independent of the size and shape of the sheath surrounding the elastic balloon.

The elastic balloon may be made essentially of silicone.

The preceding description is intended to represent, and not limit, the scope of the utility model, which is defined by the scope of the attached claims of the utility model. This and other embodiments are within the scope of the following utility model claims.

Claims (11)

1. A pump for supplying a fluid containing: - a supporting core made with the possibility of longitudinal elongation and contraction along the axis of the pump; - a limiter made to limit the longitudinal elongation of the support core to a predetermined maximum length; and - expandable elastic balloon attached to the support core in at least one place and designed to receive fluid. 2. The pump according to claim 1, also containing a shell surrounding the elastic balloon and at least a portion of the supporting core. 3. The pump according to claim 2, in which the shell has a size and shape such that when the elastic balloon is filled with fluid, the elastic balloon has a size and position that are independent of the size and shape of the shell. 4. The pump according to claim 2, in which the shell has such a size and length that when the elastic balloon is filled with fluid, there is a gap between the outer surface of the elastic balloon and the inner surface of the shell. 5. The pump according to claim 1, in which the elastic balloon is made of silicone. 6. The pump according to claim 1, in which the supporting core contains a first part and a second part, made for longitudinal sliding relative to each other. 7. The pump according to claim 6, also containing a connector for connecting the first part and the second part. 8. The pump according to claim 1, in which the limiter comprises a ball bearing located in the channel. 9. The pump of claim 8, wherein the channel length is determined based on a predetermined maximum length of the support core. 10. The pump according to claim 1, in which the supporting core is made for longitudinal elongation when the fluid enters the elastic balloon, and to reduce when the fluid exits the elastic balloon. 11. The pump according to claim 1, in which the pump is designed to supply fluid with a constant flow rate.

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