Medical fluid delivery system with distendable drain reservoir

Abstract

A medical fluid delivery system may be provided, comprising a supply reservoir, a supply tube, an exchange port, and a drain reservoir secured to the exchange port with a locking ring, wherein a wall of the drain reservoir is configured to expand in surface area responsive to an outward fluid pressure upon an interior surface of the drain reservoir to allow the drain reservoir to distend to accommodate fluid from the exchange port.

Description

TITLEMEDICAL FLUID DELIVERY SYSTEM WITH DISTEND ABLE DRAIN RESERVOIRCROSS-REFERENCES TO RELATED DISCLOSURES

[0001] The present disclosure claims the benefit of and priority to U.S. Provisional Patent Application No.: 63 / 550,423 titled “MEDICAL FLUID DELIVERY SYSTEM WITH DISTEND ABLE DRAIN RESERVOIR” and filed on 2024-02-06, which is incorporated herein in its entirety.BACKGROUND

[0002] In-home medical fluid delivery systems often use a drain bag similar to that which supplies fluid. Conventional drain bags involve numerous complex parts resulting in unnecessary plastic waste and complex manufacturing processes. These conventional drain bags may also present operational challenges to non-medical professionals.SUMMARY

[0003] The present disclosure provides a medical fluid delivery system. The medical fluid delivery system may be an in-home peritoneal dialysis therapy system, and includes a distendable drain reservoir. The distendable drain reservoir is a low cost, easily operable single use drain reservoir including a tube having a first end which is open to accept drain fluid and a second end which is closed, opposite to the first end. The tube is manufactured with a flexible wall material allowing a diameter of the tube (and thus the distendable drain reservoir as a whole) to distend to accommodate fluid flowing into the first end.

[0004] Additional features and advantages of the disclosed medical fluid delivery system with distendable drain reservoir are described in, and will be apparent from, the following Detailed Description and the Figures. The features and advantages described herein are not all-inclusive and, in particular, many additional features and advantages will be apparent to one of ordinary skill in the art in view of the figures and description. Moreover, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes, and not to limit the scope of the inventive subject matter.BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Figure 1 illustrates a medical fluid delivery system with an empty distendable drain reservoir, according to embodiments of the present disclosure.

[0006] Figure 2 illustrates a medical fluid delivery system with a distendable drain reservoir containing fluid, according to embodiments of the present disclosure.

[0007] Figure 3 illustrates a side profile view of a distendable drain reservoir with a locking ring, according to embodiments of the present disclosure.

[0008] Figure 4 illustrates an isometric view of a locking ring, according to embodiments of the present disclosure.

[0009] Figure 5A illustrates a section view of an exchange port, a distendable drain reservoir, and a locking ring prior to installation of the distendable drain reservoir, according to embodiments of the present disclosure.

[0010] Figure 5B illustrates the section view of Figure 5 A during installation of a distendable drain reservoir, according to embodiments of the present disclosure.

[0011] Figure 5C illustrates the section view of Figure 5 A following installation of a distendable drain reservoir, according to embodiments of the present disclosure.DETAILED DESCRIPTION

[0012] The present disclosure provides a distendable drain reservoir, in which an enclosed volume that may distend to accommodate a volume of drained liquid is provided. The distendable drain reservoir is a user friendly, single use, stretchable reservoir that reduces material cost and environmental impact compared to traditional drain reservoir systems currently used with medical solution delivery systems. Production advantages over traditional drain reservoirs are provided by the distendable drain reservoir, such that production of the distendable drain reservoir simply requires the production of a balloon-like vessel and a hard plastic ring. This is in contrast to traditional drain reservoirs, which require tubing, connectors, seals, and a relatively complex reservoir design to be manufactured, increasing complexity and materials consumed.

[0013] Figure 1 shows a medical fluid delivery system 100 with an empty distendable drain reservoir 140, according to embodiments of the present disclosure. The medical fluid delivery system 100 has a supply reservoir 110, a supply tube 120, an exchange port 130, and a distendable drain reservoir 140 with a locking ring 142. The supply reservoir 110 is filled with supply fluid 112 which flows down the supply tube 120 to a first orifice of the exchange port 130. The exchange port 130 interfaces with an apparatus which supplies a biological subject with supply fluid 112 from the first orifice of the exchange port 130 while allowing drain fluid 144 from the biological subject to drain to a second orifice of the exchange port 130. The distendable drain reservoir 140 is affixed to the exchange port 130 with the locking ring 142, and the distendable drain reservoir 140 is kept in fluid communication with the second orifice of the exchange port 130.

[0014] The supply reservoir 110, the supply tube 120, the exchange port 130, and the locking ring 142 may be made of any appropriate material, including but not limited to plastic, latex, rubber, cellulose, composites, or combinations thereof. The distendable drain reservoir 140 may be made of any material sufficiently strong and elastic, and these characteristics may be chosen to permit the distendable drain reservoir 140 to stretch to accommodate an equivalent volume of supply fluid 112 to that which is initially present in the supply reservoir 110. It will be appreciated that elements presented in the figures may be in different proportions than illustrated.

[0015] Figure 2 shows a medical fluid delivery system 200 with a distendable drain reservoir 140 containing drain fluid 144, according to embodiments of the present disclosure. The medical fluid delivery system 100 has a supply reservoir 110, a supply tube 120, an exchange port 130, and a distendable drain reservoir 140 with a locking ring 142. The supply reservoir 110 contains supply fluid 112 which flows down the supply tube 120 to a first orifice of the exchange port 130. The exchange port 130 interfaces with an apparatus which supplies a biological subject with supply fluid 112 from the first orifice of the exchange port 130 while allowing drain fluid 144 from the biological subject to drain to a second orifice of the exchange port 130. The distendable drain reservoir 140 is affixed to the exchange port 130 with the locking ring 142, and the distendable drain reservoir 140 is kept in fluid communication with the second orifice of the exchange port 130. Ingress of the drain fluid 144 from the second orifice of the exchange port 130 causes the distendable drain reservoir 140 to distend. Distention of the distendable drain reservoir 140 is driven by a gravitational force acting upon the drain fluid 144 from the second orifice of the exchange port 130, causing a heightened fluid pressure applied to an inner surface at a bottom endof the distendable drain reservoir 140 and forcing walls of the distendable drain reservoir 140 to bulge outwards as illustrated.

[0016] Figure 3 shows a side profile view of a distendable drain reservoir 140 with a locking ring 142, according to embodiments of the present disclosure. The distendable drain reservoir 140 may have wall thicknesses selected for strength and elasticity. Walls which are too thick may not distend properly at fluid pressures achievable via gravity alone, while walls which are too thin may rupture under those same fluid pressures. For example, an example distendable drain reservoir 140 may be made from latex and may have wall thicknesses between 0.12 millimeters (mm) and 0.5 mm when empty. Filling the distendable drain reservoir 140 may cause the wall thicknesses to decrease drastically as the distendable drain reservoir 140 distends. For example, the example distendable drain reservoir 140 referenced above may, when full, have wall thicknesses between 0.012 mm and 0.05 mm. The example distendable drain reservoir 140 may have a length in the longitudinal dimension of between 25 mm and 400 mm.

[0017] The distendable drain reservoir 140 may comprise an envelope including a closed end portion, a port connection portion, and a distendable wall extending between the closed end portion and the port connection portion. The envelope may be watertight in a first configuration; having a first thickness of the distendable wall and defining a first volume between the port connection and the closed end portion described by the distendable wall. The envelope may also be watertight in a second configuration; having a second thickness of the distendable wall and defining a second volume between the port connection and the closed end portion described by the distendable wall. The first thickness may be greater than the second thickness while the first volume may be less than the second volume.

[0018] The distendable drain reservoir 140 may include a locking ring 142 configured to secure the port connection portion to a port or tube (e.g., the second orifice of the exchange port 130). The locking ring 142 may be a full ring, a C ring, a crimp ring, a spiral ring, or any other design of locking or retaining ring capable of securing a distendable drain reservoir to a port. The locking ring 142 may also be made of any rigid material capable of being fashioned into a ring shape, including but not limited to plastic, metal, cellulose, glass, silicone, or wood. For example, a locking ring 142 may be made from silicone and may have wall thicknesses between 0.5 mm and 10 mm and an inner diameter between 1 mm and 25 mm. The locking ring may have a length in the longitudinal dimension of between 4 mm and 50 mm.

[0019] The distendable drain reservoir 140 may have a shape that is either substantially tubular, wherein an undistended cross section cut from a transverse plane of the distendable drain reservoir 140 is substantially similar in diameter and shape along a majority (e.g., at least 90%) of the drain reservoir’s longitudinal length and where the longitudinal length of the distendable drain reservoir 140 increases when the distendable drain reservoir 140 distends, or substantially globular, where the undistended cross section cut from the transverse plane widens then narrows in diameter as one moves away from an opening of the distendable drain reservoir 140. Globular embodiments may include a neck or stem of constant diameter adjacent to the opening. A lip may be provided at an opening of the port connection portion of the distendable drain reservoir 140, which may prevent the distendable drain reservoir 140 from slipping underneath the locking ring 142. The lip may comprise a bead of material disposed around an outer edge of the port connection portion. The lip may be fashioned from a same material as that of other portions of the distendable drain reservoir 140.

[0020] Unlike traditional drain bags, which have a fixed internal volume, the distendable drain reservoir 140 offers a variable volume. Although traditional drain bags may include accordion joints or other expansion features that fold / unfold to save of space when in an unfilled configuration, these drain bags must include sufficient material to define those expansion features in addition to the walls and support structures of the bag. These expansion features add additional weight and manufacturing complexity to the drain bags, and are often a point of failure due to faults in joints or weakness / fatigue at folded sections. Additionally, drain bags may often be overdimensioned to avoid potential overflow during use, thereby leading to material waste. In contrast, the distendable drain reservoir 140 has a first volume in an unused (e.g., un-distended) state and a second volume in a used (e.g., distended) state, and the second volume adjusts to match the volume of the drain fluid 144 in the distendable drain reservoir 140. The second volume changes by stretching the material from which the distendable drain reservoir 140 is made. The second volume of the distendable drain reservoir 140 (e.g., in the distended state) may correspond to a volume of drain fluid 144 held in the distendable drain reservoir 140, which may in turn correspond to a volume of supply fluid 112 initially held in a supply reservoir 110 of a medical fluid delivery system. The supply reservoir 110 may be configured to supply fluid 112 to a biological subject via an exchange port 130, and a same fluid 112 or a different fluid may drain through the exchange port 130 into the distendable drain reservoir 140. Accordingly, the space occupied by thedistendable drain reservoir 140 (either in use or in storage), the material used by the by the distendable drain reservoir 140, and the complexity of manufacture of the distendable drain reservoir 140 may all be reduced compared to traditional drain bags, while also increasing the ease of use and reliability of the distendable drain reservoir 140 compared to traditional drain bags.

[0021] Figure 4 illustrates an isometric view of a locking ring 142, according to embodiments of the present disclosure. The locking ring 142 may be a full ring, a C ring, a crimp ring, a spiral ring, or any other design of locking or retaining ring capable of securing a distendable drain reservoir (140) to a port (see Figure 5A, Figure 5B, and Figure 5C). The locking ring 142 may also be made of any rigid material capable of being fashioned into a ring shape, including but not limited to plastic, metal, cellulose, glass, silicone, or wood. For example, a locking ring 142 may be made from acrylonitrile butadiene styrene and may have wall thicknesses between 0.5 mm and 10 mm and an inner diameter between 1 mm and 25 mm. The locking ring 142 may have a length in the longitudinal dimension of between 4 mm and 50 mm.

[0022] Figure 5A illustrates a section view of an exchange port 130, a distendable drain reservoir 140, and a locking ring 142 prior to installation (or after removal) of the distendable drain reservoir 140, according to embodiments of the present disclosure. The exchange port 130 is adjacent to the distendable drain reservoir 140 with the locking ring 142 circumferentially disposed around an outer surface of the distendable drain reservoir 140.

[0023] Figure 5B illustrates the section view of Figure 5 A during installation of a distendable drain reservoir 140, according to embodiments of the present disclosure. The distendable drain reservoir 140 is circumferentially disposed around an outer surface of an exchange port 130. A locking ring 142 is in turn circumferentially disposed around an outer surface of the distendable drain reservoir 140 but is positioned such that the locking ring 142 does not overlap the exchange port 130 along a longitudinal axis of the distendable drain reservoir 140. The distendable drain reservoir 140 is thus not secured adequately to the exchange port 130 and may slide off of the exchange port 130. The distendable drain reservoir 140 and the locking ring 142 may alternatively engage with a tube or any other structure capable of fitting within the distendable drain reservoir 140 and the locking ring 142.

[0024] Figure 5C illustrates the section view of Figure 5A following installation of a distendable drain reservoir 140, according to embodiments of the present disclosure. The distendable drain reservoir 140 is circumferentially disposed around an outer surface of anexchange port 130. A locking ring 142 is in turn circumferentially disposed around an outer surface of the distendable drain reservoir 140. The locking ring 142 is positioned to overlap the exchange port 130 in order to secure the distendable drain reservoir 140 to the exchange port 130, causing the exchange port 130 and the locking ring 142 to exert a radial clamping force on the distendable drain reservoir 140 and to form a watertight seal between an interior space of the exchange port 130 / distendable drain reservoir 140 and all spaces outside of the exchange port 130 / distendable drain reservoir 140. In some embodiments, the exchange port 130 may have a raised lip or ridge circumferentially disposed around an outer edge of the exchange port 130, positioned at an end of the exchange port 130 such that when the locking ring 142 is positioned along the distendable drain reservoir 140 to fully overlap the exchange port 130, the lip distends the distendable drain reservoir 140 outwards on an end of the locking ring 142 longitudinally opposite to an opening of the distendable drain reservoir 140 and engages with an end surface of the locking ring 142 to better secure the locking ring 142 in place.

[0025] In addition to the embodiments described herein, many examples of specific combinations are within the scope of the disclosure, some of which are detailed below:

[0026] Clause 1 : A medical fluid delivery system, comprising: a supply reservoir; a supply tube; an exchange port, in fluid communication with the supply reservoir via the supply tube; and a drain reservoir secured to the exchange port via a locking ring, wherein a wall of the drain reservoir is configured to expand in surface area responsive to an outward fluid pressure upon an interior surface of the drain reservoir to allow the drain reservoir to distend to accommodate fluid from the exchange port.

[0027] Clause 2: The system of any of clauses 1 and 3-7, wherein the drain reservoir is globular.

[0028] Clause 3: The system of any of clauses 1-2 and 4-7, wherein the drain reservoir is substantially cylindrical.

[0029] Clause d: The system of any of clauses 1-3 and 5-7, wherein the drain reservoir is made from rubber, latex, cellulose, silicone, or composites thereof.

[0030] Clause 5: The system of any of clauses 1-4 and 6-7, wherein the locking ring is made from plastic, metal, cellulose, glass, silicone, or wood.

[0031] Clause 6: The system of any of clauses 1-5 and 7, wherein the locking ring has wall thicknesses between 0.5 millimeters (mm) and 10 mm, an inner diameter between 1 mm and 25 mm, and a length in a longitudinal dimension between 4 mm and 50 mm.

[0032] Clause ?: The system of any of clauses 1-6, wherein the drain reservoir has an undistended wall thickness between 0.12 millimeters (mm) and 0.5 mm, an undistended inner diameter between 0.5 mm and 25 mm, and an undistended length in a longitudinal dimension between 25 mm and 400 mm.

[0033] Clause 8: A medical fluid delivery system, comprising: a supply reservoir; a supply tube; an exchange port, in fluid communication with the supply reservoir via the supply tube; a locking ring; and a drain reservoir secured to the exchange port via the locking ring, wherein the drain reservoir has a first configuration in which the drain reservoir contains no fluid and has a wall of a first surface area, and wherein the drain reservoir has a second configuration in which the drain reservoir contains fluid which causes the drain reservoir to distend and in which the wall has a second surface area which is larger than the first surface area.

[0034] Clause 9: The system of any of clauses 8 and 10-14, wherein the drain reservoir is globular.

[0035] Clause 10: The system of any of clauses 8-9 and 11-14, wherein the drain reservoir is substantially cylindrical.

[0036] Clause 11 : The system of any of clauses 8-10 and 12-14, wherein the drain reservoir is made from rubber, latex, cellulose, silicone, or composites thereof.

[0037] Clause 12: The system of any of clauses 8-11 and 13-14, wherein the locking ring is made from plastic, metal, cellulose, glass, silicone, or wood.

[0038] Clause 13: The system of any of clauses 8-12 and 14, wherein the locking ring has wall thicknesses between 0.5 millimeters (mm) and 10 mm, an inner diameter between 1 mm and 25 mm, and a length in a longitudinal dimension between 4 mm and 50 mm.

[0039] Clause 14: The system of any of clauses 8-13, wherein the drain reservoir has a first configuration wall thickness between 0.12 millimeters (mm) and 0.5 mm, a first configuration inner diameter between 0.5 mm and 25 mm, and a first configuration length in a longitudinal dimension between 25 mm and 400 mm.

[0040] Clause 15: A drain reservoir, comprising: an envelope including a closed end portion, a port connection portion and a distendable wall extending between the closed end portion and theport connection portion; wherein: the envelope is watertight in a first configuration having a first thickness of the distendable wall and defining a first volume between the port connection portion and the closed end portion described by the distendable wall; the envelope is watertight in a second configuration having a second thickness of the distendable wall and defining a second volume between the port connection portion and the closed end portion described by the distendable wall; the first thickness is greater than the second thickness; and the first volume is less than the second volume.

[0041] Clause 16: The reservoir of any of clauses 15 and 17-20, further comprising a locking ring configured to secure the port connection portion to an exchange port.

[0042] Clause 17: The reservoir of any of clauses 15-16 and 18-20, wherein the port connection portion defines a lip of material circumferentially disposed around an opening of the port connection portion.

[0043] Clause 18: The reservoir of any of clauses 15-17 and 19-20, wherein the distendable wall defines a stem and a globular body, and wherein the stem is a substantially cylindrical and the globular body is substantially spherical.

[0044] Clause 19: The reservoir of any of clauses 15-18 and 20, wherein the second volume corresponds to a fluid volume initially held in a supply reservoir of a medical fluid delivery system.

[0045] Clause 20: The reservoir of any of clauses 15-19, wherein the envelope is made from rubber, latex, cellulose, silicone, or composites thereof.

[0046] Certain terms are used throughout the description and claims to refer to particular features or components. As one skilled in the art will appreciate, different persons may refer to the same feature or component by different names. This document does not intend to distinguish between components or features that differ in name but not function.

[0047] As used herein, “about,” “approximately” and “substantially” are understood to refer to numbers in a range of the referenced number, for example the range of -10% to +10% of the referenced number, preferably -5% to +5% of the referenced number, more preferably -1% to +1% of the referenced number, most preferably -0.1% to +0.1% of the referenced number.

[0048] Furthermore, all numerical ranges herein should be understood to include all integers, whole numbers, or fractions, within the range. Moreover, these numerical ranges should be construed as providing support for a claim directed to any number or subset of numbers in thatrange. For example, a disclosure of from 1 to 10 should be construed as supporting a range of from 1 to 8, from 3 to 7, from 1 to 9, from 3.6 to 4.6, from 3.5 to 9.9, and so forth.

[0049] As used in the present disclosure, a phrase referring to “at least one of’ a list of items refers to any set of those items, including sets with a single member, and every potential combination thereof. For example, when referencing “at least one of A, B, or C” or “at least one of A, B, and C”, the phrase is intended to cover the sets of: A, B, C, A-B, B-C, A-C, and A-B-C, where the sets may include one or multiple instances of a given member (e.g., A-A, A-A-A, A-A- B, A-A-B-B-C-C-C, etc.) and any ordering thereof. For avoidance of doubt, the phrase “at least one of A, B, and C” shall not be interpreted to mean “at least one of A, at least one of B, and at least one of C”.

[0050] As used in the present disclosure, the term “determining” encompasses a variety of actions that may include calculating, computing, processing, deriving, investigating, looking up (e g., via a table, database, or other data structure), ascertaining, receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), retrieving, resolving, selecting, choosing, establishing, and the like.

[0051] Without further elaboration, it is believed that one skilled in the art can use the preceding description to use the claimed inventions to their fullest extent. The examples and aspects disclosed herein are to be construed as merely illustrative and not a limitation of the scope of the present disclosure in any way. It will be apparent to those having skill in the art that changes may be made to the details of the above-described examples without departing from the underlying principles discussed. In other words, various modifications and improvements of the examples specifically disclosed in the description above are within the scope of the appended claims. For instance, any suitable combination of features of the various examples described is contemplated.

[0052] Within the claims, reference to an element in the singular is not intended to mean “one and only one” unless specifically stated as such, but rather as “one or more” or “at least one”. Unless specifically stated otherwise, the term “some” refers to one or more. No claim element is to be construed under the provision of 35 U.S.C. § 112(f) unless the element is expressly recited using the phrase “means for” or “step for”. All structural and functional equivalents to the elements of the various embodiments described in the present disclosure that are known or come later to be known to those of ordinary skill in the relevant art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed in the presentdisclosure is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims.

Claims

CLAIMSThe invention is claimed as follows:

1. A medical fluid delivery system, comprising: a supply reservoir; a supply tube; an exchange port, in fluid communication with the supply reservoir via the supply tube; and a drain reservoir secured to the exchange port via a locking ring, wherein a wall of the drain reservoir is configured to expand in surface area responsive to an outward fluid pressure upon an interior surface of the drain reservoir to allow the drain reservoir to distend to accommodate fluid from the exchange port.

2. The medical fluid delivery system of claim 1, wherein the drain reservoir is globular.

3. The medical fluid delivery system of claim 1, wherein the drain reservoir is substantially cylindrical.

4. The medical fluid delivery system of claim 1, wherein the drain reservoir is made from rubber, latex, cellulose, silicone, or composites thereof.

5. The medical fluid delivery system of claim 1, wherein the locking ring is made from plastic, metal, cellulose, glass, silicone, or wood.

6. The medical fluid delivery system of claim 1, wherein the locking ring has wall thicknesses between 0.5 millimeters (mm) and 10 mm, an inner diameter between 1 mm and 25 mm, and a length in a longitudinal dimension between 4 mm and 50 mm.

7. The medical fluid delivery system of claim 1, wherein the drain reservoir has an undistended wall thickness between 0.12 millimeters (mm) and 0.5 mm, an undistended inner diameter between 0.5 mm and 25 mm, and an undistended length in a longitudinal dimension between 25 mm and 400 mm.

8. A medical fluid delivery system, comprising: a supply reservoir; a supply tube; an exchange port, in fluid communication with the supply reservoir via the supply tube; a locking ring; and a drain reservoir secured to the exchange port via the locking ring, wherein the drain reservoir has a first configuration in which the drain reservoir contains no fluid and has a wall of a first surface area, and wherein the drain reservoir has a second configuration in which the drain reservoir contains fluid which causes the drain reservoir to distend and in which the wall has a second surface area which is larger than the first surface area.

9. The medical fluid delivery system of claim 8, wherein the drain reservoir is globular.

10. The medical fluid delivery system of claim 8, wherein the drain reservoir is substantially cylindrical.

11. The medical fluid delivery system of claim 8, wherein the drain reservoir is made from rubber, latex, cellulose, silicone, or composites thereof.

12. The medical fluid delivery system of claim 8, wherein the locking ring is made from plastic, metal, cellulose, glass, silicone, or wood.

13. The medical fluid delivery system of claim 8, wherein the locking ring has wall thicknesses between 0.5 millimeters (mm) and 10 mm, an inner diameter between 1 mm and 25 mm, and a length in a longitudinal dimension between 4 mm and 50 mm.

14. The medical fluid delivery system of claim 8, wherein the drain reservoir has a first configuration wall thickness between 0.12 millimeters (mm) and 0.5 mm, a first configuration inner diameter between 0.5 mm and 25 mm, and a first configuration length in a longitudinal dimension between 25 mm and 400 mm.

15. A drain reservoir, comprising: an envelope including a closed end portion, a port connection portion and a distendable wall extending between the closed end portion and the port connection portion; wherein: the envelope is watertight in a first configuration having a first thickness of the distendable wall and defining a first volume between the port connection portion and the closed end portion described by the distendable wall; the envelope is watertight in a second configuration having a second thickness of the distendable wall and defining a second volume between the port connection portion and the closed end portion described by the distendable wall; the first thickness is greater than the second thickness; and the first volume is less than the second volume.

16. The drain reservoir of claim 15, further comprising a locking ring configured to secure the port connection portion to an exchange port.

17. The drain reservoir of claim 15, wherein the port connection portion defines a lip of material circumferentially disposed around an opening of the port connection portion.

18. The drain reservoir of claim 15, wherein the distendable wall defines a stem and a globular body, and wherein the stem is a substantially cylindrical and the globular body is substantially spherical.

19. The drain reservoir of claim 15, wherein the second volume corresponds to a fluid volume initially held in a supply reservoir of a medical fluid delivery system.

20. The drain reservoir of claim of claim 15, wherein the envelope is made from rubber, latex, cellulose, silicone, or composites thereof.

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