Drinking Device to Minimize The Unpleasant Taste of Liquids

Abstract

A drinking device comprising a first compartment to hold a first fluid, a second compartment to hold a second fluid independent of the first fluid, a vertical separation between the first and second compartments, a horizontal separation closing a part of the first compartment, an opening in the horizontal separation to allow flow of the first fluid, and a lip on an upper rim of the device and opposite to the horizontal separation and adjacent to the opening to allow ingestion of the first and second fluids. A method of oral delivery of a first fluid and a second fluid, said fluids having different taste flavors, comprising delivering the first fluid in a bolus head followed by delivering the second fluid in the bolus center, and then delivering the first fluid again in the bolus tail to mask the more unpleasant flavor.

Description

FIELD OF THE INVENTION

The present invention relates generally to drinking devices. More particularly, the invention relates to a drinking device that minimizes the unpleasant taste of a liquid.

BACKGROUND

For years, people have ingested liquid medications having unpleasant flavors with difficulty. The unpleasant taste of medications can decrease the quality of life for patients and decrease compliance with useful or necessary medications. To be able to drink such medications, many people (e.g. children, incapacitated or older patients) currently try to diminish the unpleasant taste of such a medication by mixing it with a liquid that has a pleasant taste, or after the medication is swallowed, drinking as soon as possible a cup of water or another more tasty or pleasantly flavored liquid in an attempt to reduce the unpleasant flavor. Similarly, some people have difficulty ingesting certain fluids whose perception (taste or consistency) they don't favor, e.g., ingestion of radiologic contrast by patients, interfering with the nutrition of children on the autistic spectrum, or with less essential life processes like entertainment (shots of strong or unpleasant alcoholic drinks) Many people can also be particularly sensitive to the flavor of the fluid they don't like and would gag and even vomit if they are exposed to certain unpleasant flavors, e.g. many healthy children, adults with nausea (e.g. from chemotherapy, pregnancy) or who are incapacitated.

The normal oral liquid bolus drank in a single swallow for most people is likely between 13 and 21 ml. As is understood in the art, the liquid bolus is the quantity of medication or other liquid compound administered to raise its concentration in the blood to the desired effective level. Liquids in general have short oral preparation time (bolus manipulation, mastication and containing in the mouth) and typically are held in the mouth about 1 to 2 seconds before being moved by the tongue and propelled into the hypo pharynx and swallowed. But even this short period is minimized in the process of trying to swallow an unpleasant tasting medication as quickly as possible. The oral transit time (normally 0.5 to 1.5 seconds, fluoroscopically determined) is the interval from onset of the tongue movement propelling the bolus posteriorly until the bolus passes the base of the tongue. The end of the oral transit time is defined and measured as that point where the bolus tail crosses the “back of the tongue.” This point is identified (fluoroscopically) as the point where the base of the tongue crosses the posterior aspect of the ramus of the mandible. If the unpleasant taste of the medication lingers in the bolus tail, the patient will perceive this taste more saliently, resulting in prolonged unpleasant perception of the medication, gagging, and even vomiting.

The normal frequency of spontaneous swallows of saliva averages only about once every 1 to 2 minutes. Even though an increase in salivary flow and rate of swallowing can occur on stimulation with certain odors or flavors in the mouth, waiting for the saliva to wash down the lingering aftertaste of medication can unnecessarily and significantly prolong the unpleasant experience. While the exposure of the lingual taste buds to the unpleasant tasting medication during the process of swallowing can be minimized to less than the normal oral preparation (normal 1-2 seconds) and transit time (0.5 to 1.5 seconds), the perception of the aftertaste can be significantly longer than that, especially if the tail of the bolus still contains the perceptible unpleasant taste of the medication.

The previously invented drinking devices do not appear to be designed to maximize the pleasant taste of both the bolus head and tail, failing to provide an optimized solution to minimize the mixing of the pleasant and unpleasant flavored liquids in both the head and tail of the bolus, therefore potentially prolonging the unpleasant tasting part of the bolus and the duration of lingual taste bud exposure to the unpleasant medications.

One can try to minimize the unpleasant taste of medications by either indiscriminately or uniformly diluting the unpleasant taste of the medication with the pleasant taste of a better tasting liquid, but this approach has significant limitations and drawbacks. It is not always practical to mix in advance an unpleasantly flavored liquid with a pleasantly flavored one to obtain a flavor that is tolerated by all people, because different people like different flavors. Since at least a hundred years ago, drinking vessels and their variations have been invented that allow for the separate storage of two different fluids. Examples include U.S. Pat. No. 1,275,467 A, U.S. Pat. No. 2,026,449 A, U.S. Pat. No. D400,398 S, U.S. Pat. No. D369,518 S, U.S. Pat. No. D416,443 S, U.S. 2004/0232153, U.S. Pat. No. 7,243,812 B2, and U.S. Pat. No. 8,272,529 B2. But none of them allow for rapid continuous delivery and ingestion of an unmixed fluid in both the head and tail of a fluid bolus. These drinking devices produce various degrees of mixing of the unpleasant tasting medication in either the head or tail of the bolus. The problem with such approaches is that the unpleasant flavor can often still be felt in the head and/or tail of the bolus even with large dilutions of a medication, resulting in an undesirable mixture of pleasantly flavored and unpleasantly flavored fluids that prolongs the duration of perceiving a lower intensity but nevertheless unpleasant taste. One would still have to chase the remaining unpleasant taste with the more pleasantly flavored fluid, resulting in a relatively inefficient solution that can unnecessarily prolong the perception of the unpleasantly flavored medication.

There is thus a need for a drinking device that would minimize the unpleasant taste or perception of unpleasantly flavored fluids.

It was noticed that when a person quickly drinks a liquid, like with a single shot of one or more uninterrupted continuous swallows, the person initially perceives the flavor of the liquid in the beginning of drinking (the liquid bolus head) and after that the person does not significantly perceive any flavor until the person finishes swallowing the liquid, when the longer aftertaste occurs. After a person swallows the liquid, the taste receptors in the lingual buds are often still exposed to the lingering flavor of the liquid that was just swallowed, resulting in an unpleasant aftertaste. In this way when a person drinks a liquid, he or she will feel the flavor of this liquid a little in the beginning of the swallowing (the bolus head) and then will feel the lingering flavor of the liquid in the bolus tail, in the mouth, at the end of the last swallow, without significantly perceiving the taste of the body of the liquid bolus between the beginning and end of the drink.

Therefore, a better solution for minimizing the perception of the unpleasant taste of a fluid is to minimize the duration of the exposure of the unpleasant bolus to the lingual tasting buds by maximizing both the initial pleasant taste of the head bolus and the lingering pleasant taste of the tail bolus, while minimizing the duration of exposure to the unpleasant taste in the body of the bolus.

SUMMARY OF THE INVENTION

The current invention is a drinking device and a method of delivery that optimizes the perception of the unpleasant taste during the ingestion of an unpleasantly flavored fluid, e.g., medication. According to an embodiment of the invention, a drinking device minimizes the perception of an unpleasant taste by delivering the unpleasantly flavored fluid sandwiched between a pleasantly flavored fluid. According to an exemplary embodiment of the invention, a drinking device, such as a cup, has two separate compartments, one filled with a liquid medication having an unpleasant flavor and the other with a more pleasantly flavored liquid, designed such that the air and hydraulic pressure in the compartments minimize the mixing of the two liquids. When drinking from the drinking device, the unmixed more pleasantly flavored liquid is ingested first, followed by the medication liquid and then finishing again with the unmixed more pleasantly flavored liquid. In this way the person will minimize perceiving the unpleasant flavor of the medication liquid and maximize the sensing of the pleasantly favored liquid.

In accordance with another embodiment of the invention, a method of delivering two liquids with different properties (e.g., flavors) is provided by delivering the more pleasantly flavored liquid first, then delivering the unpleasantly flavored liquid second, and then delivering the pleasantly flavored fluid again. The method of delivery minimizes the mixing of the two liquids by delivering the first liquid in the head and tail of a liquid bolus and limiting the delivery of the second liquid to the center or body of the bolus.

In some embodiments of the invention, the fluid may be a tablet made into a liquid form. In some embodiments of the invention, the drinking device may be a disposable or pre-filled drinking device. In some embodiments of the invention, the compartments are separated by a separation, e.g., a vertical wall or nesting compartments.

For a better understanding of the present invention, its operation, and advantages, reference should be had to the following detailed description of the invention in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a top plan view of a drinking device with two chambers or compartments, separated by a vertical wall, according to one embodiment of the invention.

FIG. 1B is a cross-sectional view of the drinking device of FIG. 1A along line B-B.

FIG. 1C is a cross-sectional view of the drinking device of FIG. 1A along line A-A.

FIG. 2A is a cross-sectional view of the drinking device of FIG. 1A filled with two fluids.

FIG. 2B is a cross-sectional view of the drinking device of FIG. 2A being poured at a small angle.

FIG. 2C is a cross-sectional view of the drinking device of FIG. 2A being poured at a larger angle than in FIG. 2B.

FIG. 2D is a cross-sectional view of the drinking device of FIG. 2A being poured at a larger angle than in FIG. 2C.

FIG. 3A is a cross-sectional view of a drinking device of FIG. 1A with two pre-filled compartments, according to another embodiment of the invention.

FIG. 3B is a top plan view of a drinking device of FIG. 1A with one pre-filled compartment, according to another embodiment of the invention.

FIG. 4A is a top plan view of a drinking device with two compartments, one inside another, according to another embodiment of the invention.

FIG. 4B is a cross-sectional view of the drinking device of FIG. 4A along line B-B.

FIG. 4C is a cross-sectional view of the drinking device of FIG. 4A along line A-A.

FIG. 5A is a cross-sectional view of the drinking device of FIG. 4A filled with two fluids.

FIG. 5B is a cross-sectional view of the drinking device of FIG. 4A being poured at a small angle.

FIG. 5C is a cross-sectional view of the drinking device of FIG. 4A being poured at a larger angle than in FIG. 5B.

FIG. 5D is a cross-sectional view of the drinking device of FIG. 4A being poured at a larger angle than in FIG. 5C.

FIG. 6A is a cross-sectional view of a drinking device of FIG. 4A with two pre-filled compartments, according to another embodiment of the invention.

FIG. 6B is a cross-sectional view of a drinking device of FIG. 4A with one pre-filled compartment, according to another embodiment of the invention.

FIG. 6C is a top plan view of a drinking device of FIG. 4A with two pre-filled compartments, according to another embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description of the invention refers to the accompanying drawings. According to an exemplary embodiment of the invention, a drinking device, such as a cup, has two compartments adapted to hold fluids independent of one another. One embodiment is illustrated in FIGS. 1-2. FIG. 1A shows a top plan view of the drinking cup 10 having an outer rim 70 and two compartments, 50 and 60, that are divided by a vertical separation wall 20. The vertical separation wall may be curved. The outer rim 70 has a lip 71 for pouring or drinking of the liquids in a desired position of the cup. The drinking cup 10 is dissected horizontally by line A-A and vertically by line B-B.

FIG. 1B shows a vertical cross-sectional view of the drinking device of FIG. 1A along the line B-B. Compartment 60 of the drinking cup is partially closed on top with a horizontal separation wall 30. The horizontal separation wall may be curved.

FIG. 1C shows a horizontal cross-sectional view of the drinking cup of FIG. 1A along the line A-A. The drinking cup 10 has two compartments 50 and 60, divided by the vertical separation wall 20 and the horizontal separation wall 30. Compartment 50 is open on the top and compartment 60 is partially closed on the top by the horizontal wall 30. The horizontal wall 30 has a small opening 40. Compartment 50 is filled with an unpleasantly flavored liquid, e.g., medication. Compartment 60 is filled with a more pleasantly flavored liquid.

The volume of each compartment 50 and 60 depends on the position of the dividing vertical wall 20, but the sum of the volumes of the two compartments is constant and equal to the volume of the cup 10. Depending on the application, the position of the vertical wall 20 provides the desired volume ratio of the two compartments.

Drinking area 14 is the space formed between the horizontal wall 30, the cup's lip 71, and a drinker's lips. The curvature of the horizontal wall 30 helps to get the liquid into the drinking area 14 while covering the opening 40. When the level of the liquid in the drinking area 14 covers the opening 40, then no air bubbles can get inside of the closed compartment 60 to replace and allow the liquid to flow outside. Under these conditions, the liquid from the closed compartment 60 cannot flow outside into the drinking area 14.

While for smaller cups it might not be as important, for larger cups, the horizontal wall 30 curves to allow central draining of the liquid straight into the drinking area 14, so that the unpleasantly tasting liquid completely covers the opening 40. The lip 71 and the drinking area 14 may be adjusted to optimize comfort while maintaining functionality.

The outside form and the dimensions of the drinking device depend on the necessary volumes of the liquids used. The cup 10 may be oval or round or another shape that is compatible with the functional design. Optionally, the cup 10 may have a deformed area 15 in the front and a deformed area 16 on the back, to help a user hold the cup by the thumb in the front and by the fingers in the back, in the right position, to drink from the drinking area.

The working of the drinking cup according to one embodiment of the invention is illustrated in FIG. 2. Experiments were undertaken with users who drank from the drinking cup 10. Referring now to FIG. 2A, a cross-sectional view of the drinking cup of FIG. 1A is shown in position 1. Compartment 50 of the cup is filled with an unpleasantly flavored medication liquid and compartment 60 is filled with a pleasantly flavored liquid. Compartment 60 is filled completely and compartment 50 is filled to a lower level.

FIG. 2B shows position 2 of the drinking cup. The cup is tilted at an angle, allowing the pleasantly flavored liquid from the compartment 60 to flow through the opening 40 into the drinking area 14. The user will start to ingest and feel the pleasant flavor. The liquid from compartment 60 will flow into the drinking area 14, through the opening 40, only as long as the liquid level from the drinking area 14 is lower than the level from the compartment 60 and also lower than the top of the opening 40. In this way the liquid is pushed outside of the compartment 60 by differential hydrostatic pressure and the atmospheric pressure will push a bubble of air inside of the compartment 60 through the top of the opening 40.

FIG. 2C shows position 3 of the drinking cup. The drinking cup is tilted further, allowing the medication liquid from compartment 50 to flow into the drinking area 14, raising the liquid level in the drinking area 14 and closing the opening 40. In this moment or position, due to the changes in pressure and other parameters, the air bubbles cannot go inside compartment 60 and the flow of the more pleasantly flavored liquid from the compartment 60 stops.

Referring to FIG. 2D, in position 4, the drinking cup 10 is tilted even more. In this position, all the medication liquid from the compartment 50 is finished, the level of the liquid in the drinking area 14 becomes lower than the level of the liquid in compartment 60 and the opening 40 is again partially uncovered on top, permitting the air bubbles to get inside the compartment 60, and the more pleasantly flavored liquid from the compartment 60 flows freely into the drinking area 14. The pleasantly flavored liquid from the compartment 60 maybe completely or partially consumed, depending on what the user wants.

In this way the design of the drinking device minimizes the mixing of the two liquids. The design of the drinking device allows the ingestion of the liquids in an uninterrupted desired sequence that minimizes the perception of the unpleasant taste while maximizing the perception of the pleasant taste. The drinking device allows uninterrupted advantageous redistribution of the unpleasant tasting fluid in the center of the ingested bolus while maximizing the intensity of the pleasant tasting fluid in the head and tail of the ingested bolus.

According to a second embodiment of the invention shown in FIG. 3A, both compartments of a drinking cup may be pre-filled with fluids. The drinking cup of FIG. 3A may have an extension of the upper rim of the cup, forming a step 13 all around the extension of the upper rim. On this step, a removable foil 80 or 100 is sealed. The removable foil 80 closes both compartments 50 and 60. The removable foil 80 is attached after both compartments are filled up with liquids, e.g., by a pharmaceutical company. On top of the drinking cup and around the top, an antiseptic removable foil 90 may be sealed. Removable foils 80 and 90 may be removed by a user before swallowing the liquids by pulling from the edge of the foils. Edge 11 is for removal of foil 80 and edge 12 is for removal of foil 90.

FIG. 3B shows the top plan view of a drinking cup according to another embodiment of the invention, where the drinking cup has only one compartment pre-filled with a fluid. The drinking cup has a removable foil 100 that closes only compartment 50. The removable foil 100 is attached after compartment 50 is filled up with an unpleasantly flavored liquid such as a medication liquid by, e.g., a pharmaceutical company. This allows the user to fill-up the other compartment 60 with any desired flavored liquid. The foil 100 may be removed by a user prior to swallowing the liquids by pulling on the edge 11. The removable antiseptic foil 90 may be sealed on top of the drinking cup. The removable foils are removed by the user prior to drinking

An alternative embodiment of the invention is shown in FIGS. 4-5. The drinking device, such as a cup, in this embodiment has two compartments, one inside of the other to separate the two fluids. FIG. 4A shows a top plan view of the drinking cup with the two compartments 50 and 60. The drinking cup is dissected horizontally by line A-A and vertically by line B-B. FIG. 4B shows a vertical cross-sectional view of the drinking cup of FIG. 4A. The compartments are cylindrical but may be of different shapes. Compartment 50 is housed inside of the drinking cup 10 and may be removed for cleaning Compartment 60 is formed by the space between the drinking cup and compartment 50. The compartment 60 is partially closed on the top by the horizontal separation wall 30. Compartment 50 is filled with an unpleasantly flavored liquid such as a medication. Compartment 60 is filled with a more pleasantly flavored liquid, including on top of the separation wall 30.

FIG. 4C shows the horizontal cross-sectional view of the drinking cup of FIG. 4A. The horizontal separation wall 30 has an opening 40 to allow flow of the more pleasantly flavored liquid from compartment 60. The top of the cup has a lip 71 to facilitate drinking from the drinking area 14. The cup 10 may optionally have a deformed area 15 in the front and a deformed area 16 on the back, to help a user hold the cup by the thumb in the front and by the fingers in the back, in the right position.

The embodiment of FIG. 4A works on the same principle as the embodiment of FIG. 1A. FIG. 4A embodiment may be easier to manufacture and the compartments may be easier to clean. The working of the drinking cup of FIG. 4A is illustrated in FIGS. 5A-D. As shown in FIG. 5A, in position 1 of the drinking cup 10, compartment 60 is filled so that the more pleasantly flavored liquid will be both below and above the horizontal separating wall 30. Compartment 50 is filled to a lower level with the medication liquid.

In position 2, as shown in FIG. 5B, the drinking cup is tilted at an angle. The more pleasantly flavored liquid above the horizontal separation wall 30 flows first into the drinking area 14 and the drinker will first sense the good flavor of this liquid. After the liquid above the separation wall 30 finishes, the medicine liquid from compartment 50 starts to flow into the drinking area 14 and closes or seals the opening 40 so that the more pleasantly flavored liquid from the compartment 60 does not flow into the drinking area 14.

Referencing FIG. 5C, the drinking cup is tilted further in position 3. The medication liquid from the compartment 50 continues to flow into the drinking area 14 until it finishes. In position 4 shown in FIG. 5D, the drinking cup is tilted even more. The liquid level in the drinking area uncovers the opening 40, and the more pleasantly flavored liquid from the compartment 60 flows freely again into the drinking area 14.

In accordance with another embodiment of the reusable drinking cup of FIG. 4A, the compartments of the drinking cup may be pre-filled with liquids. FIG. 6A shows a cross-sectional view of a drinking cup of FIG. 4A where both compartments are pre-filled with fluids by, e.g., a pharmaceutical company. A removable foil 80 seals both compartments, filled-up to different levels. In another embodiment of the invention shown in FIG. 6B, the removable foil 80 closes only the medication liquid compartment 50. The foil 80 is attached after compartment 50 is filled up with medication liquid. A user may fill-up the other compartment 60 with any desired flavored liquid. The user may also practice a few times drinking only from the flavored liquid with the medication compartment 50 sealed. The drinking cups in both FIG. 6A and FIG. 6B may additionally have a removable antiseptic foil 90 sealed on top of the cups. The removable foils 80 and 90 may be removed by pulling on their edges 11 or 12 respectively. FIG. 6C shows the top plan view of the drinking cup of FIG. 6A, shown without the removable foils. In yet another embodiment of the invention that may be useful for people ingesting unpleasantly tasting medications, especially children, the form and the markings on the drinking cup may look similar to a commercial bottle of the pleasantly tasting liquid with the utilization instructions for the ingestion posted on the bottom of the cup, further altering the perception of the person taking the medication. In yet another embodiment, the drinking cup 10 or one or both of its compartments may include images or other inscriptions or decorations on them.

The present invention optimizes the way two liquids are delivered and perceived by designing a method that minimizes as much as possible the undesirable random mixing of two liquids with different flavors, by advantageously facilitating and redistributing in layers the position of the two liquids.

Thus, the drinking device of the present invention can be used to administer a more pleasantly flavored liquid bolus head, followed by an unpleasantly flavored liquid bolus center, followed again by a more pleasantly flavored bolus tail. This pre-determined sequence of delivery of the fluids minimizes the mixing of the two fluids. This ensures that an adequate volume of the pleasantly flavored liquid washes away the more unpleasantly flavored liquid. It greatly minimizes and essentially eliminates any lingering bad after taste. To receive the benefit of the invention, the user must drink only from the drinking area of the drinking cup and in one continuous shot. The liquids may also be swallowed in multiple swallows without interruption. As can be appreciated by a person skilled in the art, if the more unpleasantly flavored liquid is a medication, the two liquids have to be compatible from a medical point of view. Preferably, the pleasantly flavored liquid has a strong flavor and results in an intense pleasant taste. The flavor may be artificial, natural or organic.

The drinking device of the present invention is used for fluids, including liquid medications. The drinking device may also be used for solid medication that can be converted into a liquid form without affecting the efficacy of the medication. For example, a solid pill may be actively dissolved in a liquid in a separate container by stirring etc. and then added to the compartment 50 in the drinking cup 10. Depending on the pill and the dissolving liquid, the pill may also be placed directly in the compartment 50.

While the exemplary embodiments describe the use of a liquid medication, the invention may be used for other applications such as liquid diets, nutritional drinks, vitamin supplements, cocktails etc. The invention may also be used to facilitate the ingestion of an unpleasantly tasting radiologic contrast liquid prior to imaging procedures. The invention may be adapted for veterinary use to help animals ingest unpleasantly tasting fluids. Furthermore, the drinking device of the invention may be in the form of a cup, a glass, a spoon-like device, a more automatized version or any other suitable form or shape.

The drinking device of the present invention may be made from any standard materials known in the art and compatible with fluids, including materials for insulated cups. Similarly, the removable foils used in some embodiments of the invention may be made of any standard material used to close medicine or food cans and compatible with the liquids used. The foils may be fastened using any heat adhesive or other standard methods used to fasten the foils to food and medicine containers. Further, the drinking device of the present invention may be reusable or disposable.

It is to be understood that the above described arrangements are only illustrative of the application of the principles of the present invention. Numerous modifications and alternative arrangements and applications may be devised by those skilled in the art without departing from the spirit and scope of the present invention and the following claims are intended to cover such modifications and arrangements.

Claims

1. A drinking device comprising:

a first compartment to hold a first fluid;

a second compartment to hold a second fluid independent of the first fluid;

a vertical separation between the first and second compartments;

a horizontal separation closing a part of the first compartment;

an opening in the horizontal separation to allow flow of the first fluid; and

a lip on an upper rim of the device and opposite to the horizontal separation and adjacent to the opening to allow ingestion of the first and second fluids.

2. The drinking device of claim 1, wherein the second compartment is adjacent to the first compartment.

3. The drinking device of claim 1, wherein the second compartment is inside the first compartment.

4. The drinking device of claim 3, wherein the second compartment is removable.

5. The drinking device of claim 1, wherein the first and second fluids flow at different times in a pre-determined sequence.

6. The drinking device of claim 1, wherein the flow of first and second fluids minimizes their mixing.

7. The drinking device of claim 1 further comprising:

an extension of the upper rim of the device; and

a foil to close the second compartment, said foil sealed to the extension.

8. The drinking device of claim 7, wherein the second compartment is pre-filled with a fluid.

9. The drinking device of claim 1 further comprising:

an extension of the upper rim of the device; and

a foil to close first and second compartments, said foil sealed to the extension.

10. The drinking device of claim 9, wherein both the compartments are pre-filled with fluids.

11. The drinking device of claim 9, wherein the foil is removable.

12. The drinking device of claim 7 further comprising an antiseptic foil, said antiseptic foil sealed around the top of the device.

13. The drinking device of claim 1, wherein the front and back of the device have an indentation on the outside to allow holding the device.

14. The drinking device of claim 1, wherein:

the first fluid is a liquid with a first flavor; and

the second fluid is a liquid medication with a different second flavor.

15. A method of oral delivery of a first fluid and a second fluid, said fluids having different taste flavors, comprising:

first delivering the first fluid in a bolus head;

then delivering the second fluid in the center of the bolus; and

finally delivering the first fluid again in the tail of the bolus.

16. The method of claim 15, wherein the sequence of delivery of the first and second fluids minimizes their mixing.

17. The method of claim 16, wherein the sequence of delivery of the first and second fluids masks the flavor of the second fluid.