Single-use disposable elapsed time indicator with volatile fluid - Patent Application 20070122997

Abstract

The single-use disposable elapsed time indicator and method for using the same can include an indicator having a chamber and a longitudinal channel for receiving a volatile fluid. A sponge is disposed and secured within the longitudinal channel and configured to allow evaporation of the volatile fluid from within the longitudinal channel to outside the longitudinal channel. A spring is included within the longitudinal channel that presses against an end of the chamber and urges a plunger, the plunger being secured and movable within the longitudinal channel along its longitudinal axis. The spring is configured to apply a force to the plunger along the longitudinal axis within the longitudinal channel as the volatile fluid in the longitudinal channel evaporates through the sponge, moving the plunger from the first end of the chamber toward the second end of the chamber. Movement of the plunger thereby indicates elapsed time along the graduated scale.

Description

[Technical Field]

[0001] The present disclosure relates generally to single-use, disposable elapsed time indicators, and more particularly to elapsed time indicating devices that can be used with medical devices that operate based on the evaporation of a volatile fluid from within the indicator. [Background technology]

[0002] Many medical devices have a limited shelf life, meaning that once the device is activated, it is designed to be used for a limited period of time. Such products are usually associated with a single event, a limited time period, or limited access. For example, nearly all modern disposable medical devices, such as syringes, needle-free access connectors, needle-free connectors (NFC), and catheters, have a desired expiration date once the device is activated or put into use.

[0003] In some cases, medical professionals record or symbolize the start time when a device is put into use, however, this is not always the case, and often the length of time the device will be used is unknown. Summary of the Invention [Problem to be solved by the invention]

[0004] There is a continuing need for disposable elapsed time indicators that can be used in medical environments, and in particular, for progress indicators that can show the elapsed and remaining time period to provide medical professionals with sufficient time to make preparations for the particular device being monitored. [Means for solving the problem]

[0005] Aspects of the subject technology relate to a single-use, disposable elapsed time indicator that includes a spring configured to exert a force on a plunger to move the plunger along a longitudinal channel as volatile fluid evaporates from the longitudinal channel over a predetermined time. The longitudinal channel may also include a graduated scale. Movement of the plunger due to evaporation of the volatile fluid advantageously marks the elapsed time along the graduated scale. Such an indicator may include a chamber having a first end, a second end opposite the first end, and a longitudinal channel between the first and second ends for receiving the volatile fluid. A sponge is disposed at the second end of the chamber and secured within the longitudinal channel. Such a sponge is configured to allow the volatile fluid to evaporate from within the longitudinal channel to an exterior of the chamber, e.g., the external atmosphere. A spring is included within the longitudinal channel. The spring has a first end and a second end opposite the first end, the first end of the spring pressing against the first end of the chamber, and the second end of the spring pressing against a plunger fixed and movable within the longitudinal channel along a longitudinal axis (X). A graduated scale is provided along the longitudinal axis of the longitudinal channel to indicate an elapsed period of time. The spring is configured to apply a force to the plunger along the longitudinal axis within the longitudinal channel as the volatile fluid in the longitudinal channel evaporates through the sponge, moving the plunger from the first end of the chamber toward the second end of the chamber, thereby indicating the elapsed time on the graduated scale.

[0006] Additional aspects of the subject technology include methods of using a single-use, disposable elapsed time indicator. Such methods can include an indicator that includes a spring configured to exert a force on a plunger to move the plunger along the longitudinal channel as the volatile fluid evaporates from the longitudinal channel over a predetermined time period, and that includes activating the indicator by exposing the volatile fluid to an exterior of the longitudinal channel. Such exposure can be performed by removing a cover seal at one end of the longitudinal channel.

[0007] The foregoing embodiments may include one or more of the following features, individually or in combination: For example, the volatile fluid may include an alcohol, such as isopropanol and / or ethanol, an ether, a glycol, or the like, or other such volatile fluids used in the medical field.

[0008] Additional advantages of the subject technology will become readily apparent to those skilled in the art from the following detailed description, wherein only certain aspects of the subject technology are shown and described by way of example only. As will be understood, the subject technology is capable of other and different configurations, and its several details are capable of modification in various other respects, all without departing from the subject technology. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.

[0009] The accompanying drawings, which are included to provide a further understanding and are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of embodiments of the present disclosure. [Brief explanation of the drawings]

[0010] [Figure 1] 1 illustrates a single-use disposable elapsed time indicator device according to aspects of the present disclosure. [Figure 2] 2 is another view of the single-use disposable elapsed time indicator device of FIG. 1. [Figure 3]2 is a cross-sectional view of the single-use disposable elapsed time indicator device of FIG. 1. [Figure 4A] 2 is an exploded view of the single-use disposable elapsed time indicator of FIG. 1. FIG. [Figure 4B] 2 is an exploded view of the single-use disposable elapsed time indicator of FIG. 1. FIG. [Figure 5A] 10A-10C illustrate the operation of using a single-use disposable elapsed time indicator according to aspects of the present disclosure. [Figure 5B] 10A-10C illustrate the operation of using a single-use disposable elapsed time indicator according to aspects of the present disclosure. [Figure 5C] 10A-10C illustrate the operation of using a single-use disposable elapsed time indicator according to aspects of the present disclosure. [Figure 5D] 10A-10C illustrate the operation of using a single-use disposable elapsed time indicator according to aspects of the present disclosure. [Figure 6A] FIG. 10 shows a single use disposable elapsed time indicator in an initial state. [Figure 6B] FIG. 10 shows a single use disposable elapsed time indicator in an expired state. [Figure 7] 10A-10C illustrate a method of using a single-use disposable elapsed time indicator device according to aspects of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] The detailed description set forth below is a description of various configurations of the subject technology and is not intended to represent the only configurations in which the subject technology may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the subject technology. Accordingly, dimensions are provided as non-limiting examples of certain aspects. However, it will be apparent to those skilled in the art that the subject technology may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form to avoid obscuring concepts of the subject technology.

[0012] It should be understood that the present disclosure includes examples of the subject technology and does not limit the scope of the appended claims. Various aspects of the subject technology are disclosed herein according to specific, but non-limiting examples. The various embodiments described in this disclosure can be implemented in different ways and in modified forms depending on the desired application or implementation.

[0013] Referring now more particularly to the drawings, in which like reference numerals refer to like or corresponding elements throughout the several views, FIGS. 1, 2, 3, and 4 illustrate a single-use, disposable elapsed time indicator (100) according to an embodiment of the present disclosure. As shown, the indicator includes a chamber 102 having a first end 104 and a second end 106 opposite the first end 104. The chamber also includes a longitudinal channel 108 along a longitudinal axis (X) between the first end 104 and the second end 106. In this example, the chamber 102 is a cylinder having a first opening at the first end 104 and a second opening at the second end 106. The longitudinal channel 108 can receive a volatile fluid, such as a fluid composed of an alcohol, an ether, a glycol, or the like, or other such volatile fluids used in the medical field.

[0014] A sponge 110 is disposed at the second end 106 of the chamber 102 and secured within the longitudinal channel 108. The sponge provides an evaporation barrier between the volatile fluid within the longitudinal channel and the exterior of the longitudinal channel (e.g., the external environment). The sponge has an exterior surface 110a exposed to the exterior of the chamber to allow evaporation of the fluid from the chamber. The sponge can also include a removable cover seal 122 on its exterior surface 110a to prevent evaporation of the fluid until the indicator is activated by removal of the cover seal 122.

[0015] In practicing aspects of the present disclosure, the sponge is configured to allow evaporation of a volatile fluid from within the longitudinal channels to the exterior of the chamber. In some embodiments, the sponge may be configured to wick fluid from the longitudinal channels to the exterior surface 110a of the sponge 110 to facilitate evaporation of the volatile fluid (111) from the exterior surface 110a of the sponge. The sponge may be made from a polyolefin, such as polypropylene, with embedded cellulose fibers for wicking fluid to the exterior surface of the sponge, such as a cellulose sponge.

[0016] To promote evaporation of the fluid and indicate elapsed time, a spring is included within the indicator having a plunger for applying pressure to the fluid within the longitudinal channel along the longitudinal axis, allowing the device to operate effectively even when oriented at any angle or upside down (e.g., with the outer surface 110a of the sponge 110 facing upward and away from the ground). As shown in the embodiment of FIGS. 1-4, a spring 112 having a first end 112a and an opposing second end 112b is included within the longitudinal channel 108. The first end 112a of the spring 112 presses against the first end 104 of the chamber, and the second opposing end of the spring presses against a plunger 114 that is fixed and movable within the longitudinal channel 108 along the longitudinal axis.

[0017] The spring is configured to apply a force to the plunger along the longitudinal axis within the longitudinal channel, moving the plunger from the first end of the chamber toward the opposing second end of the chamber. The spring can be constructed of plastic or metal. The plunger moves along the longitudinal axis within the longitudinal channel from the first end of the chamber toward the opposing second end of the chamber as the volatile fluid in the longitudinal channel evaporates through the sponge over a predetermined period of time. The plunger can be constructed of rubber, such as silicone rubber, or nitrile rubber, such as nitrile-butadiene rubber (NBR).

[0018] As shown in this example, a first end 112a of the spring 112 presses against a cap 105 that covers a first end 104 of the chamber 102. The cap may be a snap-on or screw-on cap to cover the first end of the chamber. The first end of the spring may be connected to the cap or may be easily removed by pressing the cap. Alternatively, a second end 112b of the spring 112 may be connected to a plunger 114 or may be easily removed by pressing the plunger. The use of a cap facilitates easy assembly and sealing of the longitudinal channel after it has been filled with a volatile fluid.

[0019] The indicator also includes a graduated scale 116 along the longitudinal axis of the longitudinal channel to indicate an elapsed period of time. The graduated scale has indicia to indicate the elapsed period of time, such as, for example, an indicia of the elapsed period in hours or days. The indicia may be in the form of a checkmark or line along with numbers, words, symbols, and may be disposed on the surface of the chamber along the viewing window. Thus, an associated elapsed period of time may be indicated by an indicia such as, for example, a checkmark with a word description of the period of time (e.g., 1st hour, 2nd hour, etc.; 1st day, 2nd day, 3rd day, 4th day, etc.) or simply a number by itself (e.g., 1, 2, 3, 4, etc.).

[0020] If the chamber or longitudinal channel is not constructed of a transparent or translucent material, such as polycarbonate, the chamber also includes a viewing window 118 along the longitudinal axis (X) of the longitudinal channel 108. Alternatively, the chamber and longitudinal channel may be constructed of a transparent material and partially surrounded by an outer shell, with the viewing window formed by a slot in the outer shell. The viewing window 118 is configured to allow the plunger to be observed along with a graduated scale so that elapsed time can be determined as fluid evaporates from the longitudinal channel. The chamber and longitudinal channel may be individually constructed of one or more of plastic, polycarbonate, polyacrylate, polyester, polyolefin such as polypropylene, acrylonitrile-butadiene-styrene copolymer, etc. The viewing window may be constructed of glass or clear plastic.

[0021] As described above, the spring is configured to apply a force to the plunger along the longitudinal axis within the longitudinal channel, moving the plunger from the first end of the chamber toward the second end of the chamber. As the volatile fluid within the longitudinal channel evaporates through the sponge, the plunger moves at a predetermined speed and is used to mark graduations in hours and / or days. Thus, various markings on the graduated scale can be used to track the elapsed time as the plunger lines up with, approaches, or crosses the markings. Various markings on the graduated scale can also be used to estimate the remaining time until the expiration date of a given device.

[0022] In aspects of the present disclosure, sample evaporation calculations can be estimated based on water evaporation and then applied to the particular fluid used within the longitudinal channel of the indicator device of the present disclosure. For example, the amount of liquid water evaporated can be calculated using the following formula: h =ΘA(x s -x), and in the above formula, g h= amount of water evaporated per hour (kg / h), Θ = (25 + 19v) = evaporation coefficient (kg / m2h), v = air velocity above the water surface (m / s), A = water surface area (m2), x s = maximum humidity ratio (kg / kg) (kg H2O in 1 kg dry air) of saturated air at the same temperature as the water surface, which is constant with specific area, and x = air humidity ratio (kg / kg) (kg H2O in 1 kg dry air). Based on a similar calculation for volatile fluids, the elapsed time can be estimated from the activation of the indicator.

[0023] Volatile fluids that can be used with indicator devices according to embodiments of the present disclosure include hand sanitizer formulations, such as those containing 50-75% alcohol, such as isopropanol or ethanol, ethers, glycol ethers, or other such volatile fluids used in the medical field. For example, alcohol formulations containing 50%-100% by volume, e.g., 70-100% by volume, of alcohol, such as isopropanol or ethanol, are useful volatile fluids.

[0024] Indicator devices according to aspects of the present disclosure can also include wings (120) or flat protrusions from the chamber. Such wings can be used to label and identify the indicator. Indicator devices according to aspects of the present disclosure can also include fasteners for securing the indicator to a medical device. For example, the wings can include holes (not shown) through which a wire or string can be threaded and used to fasten the indicator to a particular medical device for tracking elapsed time. Alternatively, or in combination with a string or wire, indicator devices according to aspects of the present disclosure can also include an adhesive, such as a peel-off sticker, on the surface of the indicator to adhere the indicator to the medical device.

[0025] 4A-4B can be easily assembled by securing sponge 110 within the second end of longitudinal channel 108, followed by adding volatile fluid within longitudinal channel 108. Plunger 114, spring 112, and cap 105 can then be assembled onto the first end of the longitudinal channel. Advantageously, single-use, disposable elapsed time indicators according to aspects of the present disclosure can be sterilized; that is, the indicator can be subjected to radiation or heat sufficient to sterilize the device.

[0026] FIGS. 5A-5D and 6A-6B illustrate the operation of a single-use, disposable elapsed time indicator according to an embodiment of the present disclosure. As shown in the packed state in FIG. 5A, the plunger is closest to the first end of the longitudinal channel with the spring in its most compressed state. When the cover seal 122 is removed, the indicator is activated and evaporation of the fluid in the longitudinal channel begins. The evaporation rate of the volatile fluid in the channel is a function of time and depends, in part, on the nature of the fluid, the sponge, and the volume of the fluid. During evaporation of the volatile fluid, the spring moves the plunger toward the second end of the longitudinal channel. FIGS. 5B-5D show the plunger at various times after removal of the cover seal. For example, FIG. 5C shows the plunger halfway through the elapsed time period, and FIG. 5D shows the plunger at the final, expiring elapsed time period.

[0027] As another example, FIGS. 6A and 6B show a single-use, disposable elapsed time indicator device in an initial state and an expired state, respectively. As shown in FIG. 6A, the spring 112 is compressed, and the plunger 114 is closest to the first end 104 of the longitudinal channel. When the indicator is activated, for example, when the cover seal covering the sponge is removed, the plunger begins to slowly move toward the second end of the longitudinal channel over time due to evaporation of volatile fluid within the channel. As shown in FIG. 6B, when the indicator expires, the spring has moved the plunger to its final position, closest to the second, opposite end of the longitudinal channel. In this final position, the indicator changes to prompt a medical professional to take action upon expiration of the elapsed time, such as cleaning or replacing the particular medical device.

[0028] Additional aspects of the subject technology include methods of using a single-use, disposable elapsed time indicator. Such methods can include an indicator including a spring configured to exert a force on a plunger to move the plunger along the longitudinal channel as the volatile fluid evaporates from the longitudinal channel over a predetermined time period, and activating the indicator by exposing the volatile fluid to the exterior of the longitudinal channel. Such exposure can be performed, for example, by removing a cover seal at one end of the longitudinal channel to expose the volatile fluid to the atmosphere. FIG. 7 illustrates an exemplary method of using a single-use, disposable elapsed time indicator according to aspects of the present disclosure. In step 710, the indicator (e.g., the single-use, disposable elapsed time indicator 100) is fastened to a medical component (e.g., a needleless connector, an intravenous set, a urine bag, a secondary set, an oncology set, etc.). In aspects of the present disclosure, the indicator can be fastened to the medical device by adhesive, string, or the like.

[0029] An indicator according to the present disclosure may be activated by removing a cover seal from one end of the longitudinal channel, for example, by removing the cover seal (e.g., cover seal 122) to activate the indicator in step 720. For example, the cover seal (e.g., cover seal 122) may be peeled or removed from the outer surface 110a of the sponge 110 to expose the volatile fluid in the longitudinal channel 108 to the outside atmosphere.

[0030] In step 730, a determination of the elapsed time since activation of the indicator is determined by observing the position of the plunger along the graduated scale. As the volume of volatile fluid in the longitudinal channel decreases, for example, due to evaporation of fluid out of the channel, e.g., into the atmosphere, the plunger moves toward the second end of the longitudinal channel at a predetermined speed. Markings along the longitudinal channel indicate the elapsed time at different marks, and recording the position of the plunger along the graduated scale indicates the elapsed time, thus providing a visual reference to the elapsed time associated with the level of fluid remaining at any given time after activation.

[0031] Examples The following examples are intended to further illustrate certain preferred embodiments of the invention and are not limiting in nature. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, numerous equivalents to the specific substances and procedures described herein.

[0032] In an experiment, isopropyl alcohol was added to an open tube and hand sanitizer gel was added to a separate open tube. The volume of the liquid was recorded over several days. A nearly linear decrease in volume of each liquid was observed each day, demonstrating that such liquids can be used as volatile fluids in single-use, disposable elapsed time indicators according to the present disclosure.

[0033] It is understood that any particular order or hierarchy of blocks in the disclosed process methods describes an example approach. Based on design or implementation preferences, it is understood that the particular order or hierarchy of blocks in the processes may be rearranged, or all of the blocks described may be performed. In some implementations, any of the blocks may be performed simultaneously.

[0034] This disclosure is provided to enable any person skilled in the art to practice the various aspects described herein. This disclosure provides various examples of the subject technology, and the subject technology is not limited to these examples. Various modifications of these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects.

[0035] Reference to a singular element is not intended to mean "one and only one" unless expressly stated to be so, but rather "one or more." The term "some" refers to one or more unless otherwise specified. Masculine pronouns (e.g., his) include feminine and neuter pronouns (e.g., her and its), and vice versa. Headings and sub-headings, if present, are used for convenience only and do not limit the invention.

[0036] The word "exemplary" is used herein to mean "serving as an example or illustration." Any aspect or design described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects or designs. In one aspect, various alternative configurations and operations described herein may be considered at least equivalent.

[0037] As used herein, the phrase "at least one of" preceding a list of items each separated by the word "or" modifies the entire list, not each item in the list. The phrase "at least one of" does not require the selection of at least one item. Rather, the phrase allows for the inclusion of at least one of any one of the items, and / or at least one of any combination of the items, and / or at least one of each of the items. By way of example, the phrase "at least one of A, B, or C" can refer to A only, B only, or C only, or any combination of A, B, and C.

[0038] Use of a phrase such as "aspect" does not imply that such aspect is essential to the subject technology or that such aspect applies to all configurations of the subject technology. Disclosure relating to an aspect may apply to all configurations, or to one or more configurations. An aspect may provide one or more examples. A phrase such as "an aspect" may refer to one or more aspects, and vice versa. Use of a phrase such as "embodiment" does not imply that such embodiment is essential to the subject technology or that such embodiment applies to all configurations of the subject technology. Disclosure relating to an embodiment may apply to all embodiments, or to one or more embodiments. An embodiment may provide one or more examples. A phrase such as "an embodiment" may refer to one or more embodiments, and vice versa. Use of a phrase such as "configuration" does not imply that such configuration is essential to the subject technology or that such configuration applies to all configurations of the subject technology. Disclosure relating to one configuration may apply to all configurations, or to one or more configurations. A configuration may provide one or more examples. A phrase such as "one configuration" may refer to one or more configurations, and vice versa.

[0039] In one aspect, unless otherwise indicated, all measurements, values, ratings, locations, dimensions, sizes, and other specifications set forth herein, including those in the claims that follow, are approximate and not exact, and are intended to have a reasonable range consistent with the function to which they relate and that which is customary in the art to which they pertain.

[0040] It is understood that the specific order or hierarchy of steps, operations, or processes disclosed describes example approaches. It is understood that the specific order or hierarchy of steps, operations, or processes may be rearranged based on design preferences. Some of the steps, operations, or processes may occur simultaneously. Some or all of the steps, operations, or processes may be performed automatically without user intervention. Where present, the accompanying method claims present elements of the various steps, operations, or processes in a sample order, and are not intended to be limited to the specific order or hierarchy presented.

[0041] All structural and functional equivalents of the elements of the various aspects described throughout this disclosure that are known or that become known in the future to those skilled in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Furthermore, nothing disclosed herein is intended to be made available to the public in any way, regardless of whether such disclosure is expressly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. 112(f) unless the element is expressly recited using the phrase "means for," or, in the case of a method claim, the element is recited using the phrase "step for." Furthermore, to the extent terms such as "include," "have," and the like are used, such terms are intended to be inclusive, similar to the interpretation of "comprise" when used as a transitional phrase in a claim.

[0042] While the "Title," "Background," "Summary," "Brief Description of the Drawings," and "Abstract" of this disclosure are incorporated herein into this disclosure, they are provided as illustrative examples of the disclosure, not as a limiting description. This specification is presented with the understanding that they will not be used to limit the scope or meaning of the claims. Furthermore, in the "Description," it is understood that the description provides illustrative examples, and that various features are grouped together in various embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed subject matter requires more features than are expressly recited in each claim. Rather, as reflected in the following claims, inventive subject matter resides in less than all features of a single disclosed structure or operation. The following claims are incorporated herein into the "Description," with each claim standing on its own as separately claimed subject matter.

[0043] The claims are not intended to be limited to the embodiments described herein, but are to be accorded the full scope consistent with the claims by language, including all legal equivalents. Nevertheless, no claim is intended to, and no claim should be construed to, cover subject matter that does not satisfy the requirements of 35 U.S.C. §§ 101, 102, or 103.

Claims

1. A chamber (102) having a first end (104), a second end (106) opposite to the first end, and a longitudinal channel (108) between the first and second ends for receiving a volatile fluid, A sponge (110) is positioned at the second end of the chamber and fixed within the longitudinal channel, wherein the sponge (110) is configured to allow a volatile fluid to evaporate from within the longitudinal channel to the outside of the chamber, A spring (112) contained within the longitudinal channel, having a first end and a second end opposite to the first end, wherein the first end of the spring presses against the first end of the chamber, and the second end of the spring presses against a plunger fixed and movable within the longitudinal channel along the longitudinal axis, To indicate the elapsed time, a scaled scale along the longitudinal axis of the longitudinal channel and A single-use disposable elapsed time indicator (100) comprising, A single-use disposable elapsed time indicator (100) is provided, wherein the spring (112) is configured to apply force to the plunger along the longitudinal axis within the longitudinal channel as the volatile fluid from the longitudinal channel evaporates through the sponge, causing the plunger to move from the first end of the chamber toward the second end of the chamber, thereby indicating the elapsed time on the graduated scale.

2. The indicator according to claim 1, wherein the chamber has a viewing window (118) along the longitudinal channel for viewing the plunger.

3. The indicator according to claim 1, further comprising a cover seal (122) covering the sponge for preventing evaporation of the volatile fluid in the chamber.

4. The indicator according to claim 1, further comprising a fastener for fixing the indicator to a medical device.

5. The indicator according to claim 1, further comprising an adhesive on the surface of the indicator for attaching the indicator to a medical device.

6. The indicator according to claim 1, wherein the scaled scale indicates an elapsed period of hours or days.

7. The indicator according to claim 1, wherein the first end of the chamber is covered by a cap (105), and the first end of the spring presses against the cap.

8. The indicator according to claim 1, further comprising a volatile fluid in the longitudinal chamber.

9. The indicator according to claim 8, wherein the volatile fluid comprises isopropanol and / or ethanol.

10. The indicator according to claim 1, further comprising wings.

11. The indicator according to claim 1, wherein the indicator is sterilized.

12. The indicator according to claim 1, wherein the plunger (114) is made of rubber.

13. The indicator according to claim 1, wherein the chamber and the longitudinal channel are made of plastic.

14. The indicator according to claim 1, wherein the chamber and the longitudinal channel are composed of one or more of polycarbonate, polyolefin, or acrylonitrile-butadiene-styrene copolymer.

15. The indicator according to claim 1, wherein the chamber is in the form of a cylinder having a first opening at the first end and a second opening at the second end.

16. A step of providing a disposable elapsed time indicator (100) according to Claim 1, The steps include: activating the indicator by exposing the volatile fluid to the outside of the longitudinal channel; A method for measuring elapsed time, including [specific details omitted].

17. The method according to claim 16, further comprising the step of fastening the indicator to a medical device.

18. The method according to claim 16, wherein the medical device comprises a needleless connector, an intravenous set, and a urine bag.

19. The method according to claim 16, wherein the step of activating the apparatus includes the step of removing a cover seal (122) at one end of the longitudinal channel.

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