Method and system for high-speed tablet counting and dispensing

Abstract

A medicament tablet dispensing system and method dispenses any selected number of tablets, up to a maximum number, with minimal dispensing delays. During fill operations, a preset number of tablets are counted and stored in dedicated storage compartments. Dispensing operations are performed in response to dispense request commands. The fill operations are performed in a manner independent from the quantity of tablets identified by the dispense request commands. During the dispensing operations for a particular dispense request command, the preset number of tablets are emptied from one or more of the dedicated storage compartments, thereby avoiding delays associated with counting all of the dispensed tablets. Moreover, the fill operations and the dispensing operations may be performed in parallel for high-throughput dispensing applications.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates broadly to medicament tablet counting and dispensing apparatus. More particularly, this invention relates to tablet feeding and counting apparatus which are adapted to dispense any selected number of tablets, up to a maximum number, with minimal dispensing delay.

2. State of the Art

In retail, hospital, and mail order medication dispensing, a large number of different prescriptions of single dose medications, such as tablets, must be filled. (Hereinafter, reference to “tablets” should be understood for purposes herein as being generic to tablets, capsules, caplets and any other solid dose medication).

Larger quantity prescriptions are often filled with the aid of a counting apparatus intended to more rapidly count different quantities of different tablets successively. For example, a prescription for ninety tablets of 10 mg Claritin® may need to be filled after a prescription for sixty tablets of 400 mg Motrin®.

With an automatic tablet counter, the pharmacist obtains a bulk container of a prescription medication from a shelf and then pours from the container a quantity of tablets into a hopper of the counting apparatus. The pharmacist then sets the counting apparatus to the number of tablets to be counted, e.g., ninety. Assuming at least the required number of tablets for the prescription has been poured into the hopper, the pharmacist waits while the counting apparatus counts the required number of tablets and dispenses the tablets into a patient prescription bottle. The excess tablets are discharged back into the bulk container, which is then replaced on the shelf. It has been found that the time taken to discharge the excess tablets can be equal to or greater than the time required to count the prescription.

Each prescription medication must be obtained from a bulk storage container located in stock, which must be opened prior to use and closed after use. In order to minimize the time taken to dispense a prescription, counter manufacturers have provided “cassette counters” for retail, hospital, and mail order pharmacies. Each cassette is designed for a specific size and shape capsule, tablet, or caplet. The cassettes are pre-filled by the pharmacist with bulk quantities of the appropriate prescription drugs, and are used to store bulk quantities rather than using the container supplied by the manufacturer. The prescription medication is then dispensed directly from the cassette. The use of cassettes eliminates the time needed to open the manufacturer's original container, the time needed to return excess tablets to the container, and the time needed to close the container.

However, there are situations, particularly in bulk mail order pharmacies and high volume hospital dispensing, where greater dispensing speed is desired than is currently provided by automatic dispensing systems, particularly for the most frequently dispensed medications.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide a system for dispensing a selected quantity of tablets extremely rapidly, irrespective of the type of tablet and the quantity of tablets dispensed.

It is another object of the invention to provide a system for dispensing tablets which functions with all tablets regardless of size, shape, and weight.

It is an additional object of the invention to provide a system for dispensing tablets which is not prone to clogging.

It is a further object of the invention to provide a system for dispensing tablets which is efficient.

In accord with these objects, which will be discussed in detail below, a system and method for storing and dispensing discrete objects, such as ‘tablets’ (stated above to be generic for tablets, capsules, caplets and any other solid dose medication), is provided and adapted to dispense a number of tablets, up to a maximum number, without a delay associated with counting the tablets.

The system and methodology include first counting and storing a preset number of tablets in respective dedicated chambers (storage locations), the combination of the numbers of tablets within the chambers being useful for dispensing commonly prescribed numbers of tablets.

According to one embodiment of the invention, n chambers are provided, with 2⁰, 2¹, 2², . . . ,2ⁿ⁻¹ tablets provided respectively in the individual chambers. Using such a system, any number of tablets, up to the additive combination of all the chambers (e.g., where n=7, the additive combination is 127), can be dispensed from the chambers by selectively emptying the chambers which together add up to the selected number for dispensing.

Because the number of tablets in each of the chambers is always the same, the system optionally can be hardwired to select the tablets from the required chambers without any combinatorial computation process; i.e., for any number of tablets selected for dispensing, there always exists a particular readily determinable combination of chambers which can be emptied to comprise the selected number of tablets exactly. Alternatively, the chambers can be selected by a simple computational process.

According to another embodiment of the invention, there are n chambers, where n preferably equals at least four, and the number of tablets in a particular chamber i is preferably 2ⁱ⁺², where i=1 . . . n. In accord with this embodiment, a direct feed channel is provided in addition to the chambers. The direct feed channel feeds individually counted tablets into an exit chute in combination with the tablets dispensed from the chambers. The direct feed channel is primarily provided for counting up to 2ⁱ⁺²−1 tablets, where i preferably equals one, e.g., seven tablets. As such, the direct feed channel in combination with the chambers permits dispensing of any number of tablets up to

$\sum _{i=1}^n{2}^{i+2}+7;$ e.g. where n=4, up to 127 tablets. However, it is certainly appreciated that the chambers may store a non-exponentially incremented number of tablets, and that the direct feed channel may be used to supply up to another number of tablets.

Dispensing operations are performed in response to dispense request commands. During the dispensing operations for a particular dispense request command, the preset number of tablets are emptied from one or more of the dedicated chambers, thereby avoiding delays associated with counting all of the dispensed tablets.

After the selected chambers are emptied tablets are fed from a feeder which stores bulk quantities of the tablet, counted, and directed into the emptied chambers to refill the chambers with the preset number of tables. Such refill operations are performed in a manner independent from the quantity of tablets identified by the dispense request commands, and may be performed in parallel with respect to the dispensing operations for high throughput dispensing applications.

The direction of the tablets into the emptied chambers for filling is preferably controlled by refill gates which open to receive or direct the required number of tablets and close once appropriately refilled. It is appreciated that only those chambers which are emptied after dispensing need to be refilled and, as such, only the number of tablets in those storage locations need to be counted.

According to another aspect of the invention, each chamber i may include subchambers which are each filled with the appropriate number of tablets for the chamber. Then, when activated, a subchamber of the chamber is emptied. The remaining filled subchambers are then ready for subsequent dispensing while the emptied subchamber is being refilled. As such, the user is not required to wait before attempting to dispense another prescription for the tablets. Moreover, during a single dispensing operation more than one subchamber of a chamber may be emptied, particularly when large numbers of tablets are to be dispensed.

In addition, an overflow chamber may be provided for extra tablets which are inadvertently fed into the refill system after the required count to fill one or more of the chambers has been met. A count is kept of the tablets in the overflow chamber, and the overflow chamber is emptied during the subsequent dispensing or when the number therein is suitable in combination with one or more other chambers to meet an input number of tablets for dispensing.

The system may include a plurality of cells, each including a plurality of chambers for a different solid dose medication. The solid dose medication may then be selected along with the number of tablets required to be dispensed.

Additional objects and advantages of the invention will become apparent to those skilled in the art upon reference to the detailed description taken in conjunction with the provided figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a medicament tablet counting and dispensing system according to the invention including a cell provided with chambers having tablets;

FIGS. 2, 3 and 4 are schematic views of the tablet counting and dispensing system of FIG. 1, showing a sequence for release and closure of exit gates;

FIGS. 5, 6 and 7 are schematic views of the tablet counting and dispensing system of FIG. 1, showing a sequence for opening and closure of refill gates;

FIG. 8 is a schematic section of a side elevation view of a first embodiment of a multi-cell tablet counting and dispensing system;

FIG. 9 is a schematic section view through line 9-9 in FIG. 8;

FIG. 10 is a schematic view of a second embodiment of a multi-cell tablet counting and dispensing system;

FIG. 11A is a perspective view of another embodiment of a multi-chamber tablet counting and dispensing system according to the invention;

FIG. 11B is a schematic view of the system of FIG. 11A;

FIG. 12 is a flow chart illustrating an exemplary control scheme in loading tablets into the multi-chamber tablet counting and dispensing system of FIGS. 11A and 11B;

FIG. 13A is a perspective view of another embodiment of a multi-chamber tablet counting and dispensing system according to the invention;

FIG. 13B1 is a schematic top view of the tablet feeder mechanism of FIG. 13A.

FIG. 13B2 is a section view through line B-B in FIG. 13B1;

FIG. 13C is an exploded view of the tablet feeder mechanism of FIG. 13A.

FIG. 13D is a perspective view of the tablet feeder mechanism of FIG. 13A.

FIG. 14 is a functional block diagram of a distributed control architecture for controlling a multi-cell tablet counting and dispensing systems according to the present invention; and

FIGS. 15A and 15B are high level flow charts illustrating exemplary control operations carried out by the respective local controllers of FIG. 14 in loading tablets into and dispensing tablets from the storage compartments of tablet counting and dispensing subsystems operably coupled to the local controllers.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Turning now to FIG. 1, a tablet dispensing system 10 is shown which includes a hopper 12 which stores a bulk quantity of tablets, a feeder 14 which feeds tablets from the hopper 12 to a cell 16, which is described in more detail below, a counter 18 which counts the tablets fed by the feeder to the cell 16, and a controller 34 which operates the cell 16 and permits a user to enter or select the number of tablets to be dispensed.

The hopper 12, feeder 14 and counter 18 may be of any type known in the art suitable for counting small discrete objects, such as tablets. For example, the hopper 12 and feeder 14 may be a vibratory bowl feeder, a mechanical feeder, or a cassette system such as described in co-pending U.S. Ser. No. 09/871,531, filed May 31, 2001, which is hereby incorporated by reference herein in its entirety, each of which may have an integrated unit which functions as both a hopper and a feeder. The counter 18 is preferably an optical system which uses an optical sensor array, such as that disclosed in co-owned U.S. Pat. No. 5,768,327, which is hereby incorporated by reference herein in its entirety. The optical sensor array of U.S. Pat. No. 5,768,327 includes an orthogonal arrangement of two discrete optical sensors which together sense objects in three dimensions. This sensor arrangement is adapted to sense multiple objects simultaneously falling past the sensors.

The cell 16 includes a plurality of vertically-stacked inclined chambers (storage locations) 20 positioned below the counter 18. Seven chambers sequentially numbered one through seven are shown in the embodiment of FIG. 1. The chambers 20 each have a fill gate 22 and an exit gate 24. When the fill gate 22 of any chamber is open, that chamber is in communication with a feed chute 26 and thereby adapted to receive tablets 28 fed from the feeder 14 and counted by the counter 18. With the respective exit gates 24 closed, each chamber 20 stores a predetermined, and preferably different, number of tablets. As discussed in more detail below, when the exit gate 24 of any chamber is in an open position, the tablets stored within the chamber 20 are released into an exit chute 30, and from the exit chute 30 the tablets are dispensed into a container 32. The fill gates and exit gates are preferably electromechanically controlled, e.g., with solenoids powered by the controller 34, to effect movement of the gates between open and closed positions.

The combination of the numbers of tablets within the plurality of chambers 20 is capable of comprising any number of tablets which is desired for dispensing. According to a preferred system, n chambers are provided, with 2⁰, 2¹, 2², . . . , 2ⁿ⁻¹ tablets provided respectively in the individual chambers 20. Using such a system, any number of tablets, up to the additive combination of all the chambers (e.g., where n=8, the additive combination is 255), can be dispensed by selectively emptying the chambers which together add up to the selected number for dispensing.

As shown in FIG. 1, in an embodiment of the invention, seven chambers 20 are provided; i.e., n=7. The chambers are provided with tablets as follows: chamber one includes one tablet (2⁰) ; chamber two includes two tablets (2¹); chamber three includes four tablets (2²); chamber four includes eight tablets (2³); chamber five includes sixteen tablets (2⁴); chamber six includes thirty-two tablets (2⁵); and chamber seven includes sixty-four tablets (2⁶).

Referring to FIG. 2, if it is desired to dispense, e.g., twenty-six tablets, twenty-six tablets are selected at the controller 34 which causes the exit gates 24 of chambers two, four and five to be opened. The gates may be opened simultaneously. However, in the embodiment of the invention as shown, where the gates swing open, the gates are preferably opened in succession and at time intervals, e.g., 0.25 seconds between each opening, starting with the gate of the lowermost chamber. The time interval prevents jamming by the tablets. As the exit gates are opened, the tablets in the respective chambers (two, eight, and sixteen tablets, respectively) are released into the exit chute 30. The sixteen tablets from chamber five fall directly into the container, while the tablets from chambers four and two are retained the open exit gates of chambers five and four respectively. Referring to FIG. 3, the exit gates 24 are then closed from the bottom up, preferably again in succession and at a short time interval, to release the retained tablets into the chute 30 for dispensing. That is, when the exit gate 24 of chamber five is closed, the tablets from chamber four which were resting on that gate are released to fall through the exit chute 30 and into the container. Likewise, when the exit gate 24 of chamber four is closed, the two tablets retained in chamber two fall into the container 32. Referring to FIG. 4, the exit gate 24 of chamber two, previously holding the two tablets is then closed.

As is discussed hereinafter, because the number of tablets in each of the particular chambers 20 is kept constant (due to refilling), the system optionally can be hardwired at the controller 34 to open the exit gates from the required chambers without any combinatorial computation process; i.e., for any number of tablets selected for dispensing, there always exists a particular readily determinable combination of chambers which can be emptied to comprise the selected number of tablets exactly, up to the maximum number of tablets stored in the cell 16.

Alternatively, the chambers can be selected by a simple computational process performed by the controller 34, for example, by first identifying the chamber having the largest number of tablets less than the selected number for dispensing, then identifying the chamber having the next largest number of tablets, provided that the addition of such number of tablets to the previously identified chamber does not exceed the selected number for dispensing, then identifying the chamber having the next largest number of tablets, provided that the addition of such number of tablets to the previously identified chambers does not exceed the selected number for dispensing, etc., until the desired number of tablets has been identified. As each chamber is identified, or after all have been identified, the exit gates are opened and closed, preferably in succession as described above, to dispense the tablets.

The tablet dispensing system requires no tablet counting time because the chambers of the cell are preloaded. The only time required is for the gates to open to release and empty the tablets from the identified chambers. While time is required to refill the emptied chambers, the refill occurs after dispensing and presumably while the system operator is completing the prescription requirement (e.g., labeling, data entry, packaging, etc.) or identifying and/or preparing the subsequent prescription information; i.e., refill occurs during system operator downtime.

After the identified chambers have been emptied, such chambers need to be refilled for subsequent dispensing operations. Referring now to FIG. 5, the fill gates 22 of the emptied chambers (chambers two, four, and five in the example) are opened, and the tablets 28 are fed by the feeder 14 from the hopper 12 to the counter 18 (which is preferably an optical counter such as disclosed in co-owned U.S. Pat. No. 5,768,327). Once the counter counts the required number of tablets for the uppermost emptied chamber (chamber two), and after a short predetermined delay to permit the tablets to fall through the fill chute 26 to the respective chamber, the fill gate of that chamber is closed, as shown in FIG. 6. Still referring to FIG. 6, then the tablets required for the next chamber (i.e., chamber four) are counted, enter the fill chute and fall through the open fill gate to the chamber. Referring to FIG. 7, once chamber four is refilled, its respective fill gate 22 is closed, and chamber five is refilled in a like manner. It is appreciated that only those chambers which are emptied after dispensing need to be refilled and, as such, only the number of tablets in those chambers need to be counted. It is also appreciated that the dispensing system is initialized by counting and directing the required number of tablets to each of the respective chambers.

Referring to FIGS. 8 and 9, a tablet dispensing system 110 may include a plurality of radially arranged cells 116 each including a plurality of chambers 120 for a different solid dose medication. Each of the cells 116 is preferably provided with its own hopper 112, feeder 114 and counter 118. The solid dose medication may be selected from a controller (not shown) along with the number of tablets required to be dispensed. A common exit chute 130 can be used for dispensing into a bottle or container.

Turning now to FIG. 10, another embodiment of a multi-cell tablet dispensing system 210 is shown. Each cell 216 includes its own hopper 212 and preferably a feeder 214. A common counter 218 may be movable between the hoppers 212, feeders 214, and the cells 216. Alternatively, the feeder 214 may be integrated with the counter 218 and also movable relative to the hoppers 212 and cells 216. From the above multi-cell system embodiments, is understood that various other configurations of a multi-cell system may be implemented.

While the preferred system includes cells with n chambers provided with 2⁰, 2¹, 2², . . . , 2ⁿ⁻¹ tablets in the respective chambers, it will be appreciated that chambers having another arrangement of tablet quantities may be used, provided that such arrangement permits the desired number of tablets to be dispensed. It is appreciated that not every number of tablet need be able to be dispensed, just those quantities which are generally prescribed. Prescribed quantities are generally in multiples of 7 or 10.

Turning now to FIGS. 11A and 11B, another embodiment of a dispensing system 310 for tablets is shown. The system 310 generally includes many of the features described above, including a hopper 12, a feeder 14, and a counter 18. The system 310 also includes a cell 316 preferably having n primary chambers 320 for storing tablets, where n is preferably greater than or equal to four. The number of tablets in a particular chamber i is preferably 2ⁱ⁺², where i=1 . . . n. Thus, for exactly four chambers 320, according to a presently preferred embodiment, a first chamber 320a preferably includes eight tablets, a second chamber 320b preferably includes sixteen tablets, a third chamber 320c preferably includes 32 tablets, and a fourth chamber 320d preferably includes 64 tablets. The cell 316 preferably also includes a fifth chamber 320e, the purpose of which is described further below. With four primary chambers, the chambers are adapted to dispense a large range of numbers of tablets, between 8 and 120 tablets, and even up to 240 using multiple chambers and double dispensing, as discussed below.

A direct feed channel 340 is provided in addition to the cell 316. The direct feed channel 340 provides automatic feed-through of individually counted tablets in a manner which bypasses the chambers 320 of the cell 316. The direct feed channel 340 is primarily provided for counting up to the number of tablets stored in the cell chamber having the fewest number of tablets. For example, if the first chamber 320a stores eight tablets, the direct feed channel 340 is provided for automatically feeding up to seven tablets into the chute 330. As such, for n=4, the chambers 320 in combination with the direct feed channel 340 permit dispensing of any number of tablets up to

$\sum _{i=1}^n{2}^{i+2}+7$ (i.e., 127 tablets), without requiring three additional chambers for 1 (2⁰), 2 (2¹) and 4 (2²) tablets, as in the prior embodiments. Moreover, there is no need to direct feed more tablets than already pre-counted and stored in a chamber.

According to a preferred aspect of the invention, each chamber 320 preferably includes a plurality of subchambers, such as 342, 344, 346. Each of the subchambers 342, 344, 346 can be provided with the respective number of tablets for that chamber 320. That is, if a chamber 320 is designated to dispense eight tablets at a time, then each of the subchambers 342, 344, 346 is preferably provided with eight tablets, though it is appreciated that at any given time one or two of the subchambers may be emptied of tablets and awaiting refill. In a preferred embodiment, the chambers 320 are generally circular, with the subchambers 342, 344, 346 defined by sectors formed by radially extending walls 348 located 120° apart about a central hub 350. The chambers 320 are preferably mounted for individual mechanical rotational movement by a motorized actuation mechanism 352. The circumference of each circular chamber 320 includes a rim 353 which preferably extends within a stationary guide 355 at the bottom of the gateway 360, described below, to facilitate rotational alignment of the chambers 320. The chambers 320 also include an outer wall 354 provided with openings 356 into each of the subchambers. An enclosure 358, shown in broken lines, is provided partially about the cell 316 to retain tablets in the subchambers 342, 344, 346 and limit release of the tablets within the subchambers. The enclosure 358 has upper and lower apertures (not shown) which permit tablets to be received into the chamber and dispensed therefrom. When a subchamber is oriented in a first direction, e.g., vertically upwards, the subchamber is positioned to receive tablets fed through its opening via the gateway 360. When a subchamber is oriented vertically downwards, the subchamber is oriented to empty its tablet contents via its opening 356 into the chute 330. When a subchamber is oriented such that its opening is not adjacent the gateway 360 or chute 330, the subchamber and enclosure 358 merely store tablet contents.

Upon receiving an input for dispensing a certain number of tablets, the necessary chambers to comprise the largest number of tablets smaller than the input number are actuated, e.g., by rotation, to empty their contents. Alternatively, all chambers are rotated and only the necessary chambers (or subchambers) are emptied, e.g., by providing actuatable gates at the openings to the subchambers. If necessary, tablets are automatically fed into the direct feed channel 340 to complete the required number of tablets. For example, if an input is received to dispense ninety tablets, the fourth, second and first chambers are rotated to empty eighty-eight (64+16+8) tablets, and the direct feed provides an additional two tablets, for a total of ninety tablets.

According to another aspect of the invention, it may be desirable to be able to dispense a relatively large number of tablets by emptying more than one subchamber of a chamber. For example, if the number of tablets input for dispensing is one hundred-eighty, and the cell includes four primary chambers, each with three subchambers, of which two such subchambers of each chamber are preferably filled at any one time, the cell may be actuated to release two subchambers, each with sixty-four tablets from the fourth chamber 320d, one subchamber with thirty-two tablets from the third chamber 320c, and one subchamber of sixteen tablets from the second chamber 320b. Four tablets automatically fed from the feeder 14 to the direct feed channel 340 complete the request.

After a dispensing operation, tablets are fed from the feeder through the gateway 360 to the appropriate chambers for subchamber refilling. The gateway 360 is a series of channels including the above described direct feed channel 340 and chamber channels 364, 366, 368, 370 which direct tablets from a funnel 372 below the feeder 14 and into the chambers 320a-e. Appropriate channels 340, 364, 366, 368, 370 are selected by operation of a plurality of actuatable gates 374. The gates 374 are movable between opened and closed positions to, at any given time, define a single path for a tablet from the funnel 372 to one of the channels 340, 364, 366, 368, 370. This permits subchambers to be refilled with the designated number of tablets after a dispensing operation, as well as the output of individual tablets through the direct feed channel 340.

After a subchamber is filled with the appropriate number of tablets, it is possible that an additional tablet will have already been fed by the feeder 14 to the counter 18, but not yet counted. As such, after filling a chamber, the gates 374 move to a default position whereby such an extra tablet is provided to the fifth chamber 320e. The fifth chamber 320e operates as a temporary repository for such tablets. Generally, no more than one extra tablet would be counted per chamber. As such, with four chambers, up to four tablets may be provided to the fifth chamber upon each refill of the chambers. A count is kept of the tablets in the fifth chamber 320e, and the tablets in the fifth chamber are preferably dispensed along with the tablets in other appropriate chambers (i) when the number in the fifth chamber 320e is suitable in combination with one or more other chambers 320a, 320b, 320c, 320d to meet an input number of tablets for dispensing, or (ii) during every dispensing in combination with one or more other chambers and an appropriate number of tablets provided through the direct feed channel 340. Emptying the fifth chamber 320e whenever tablets are stored therein, regardless of how many tablets are in the fifth chamber, prevents inadvertent storage of a relatively large number of tablets which may be difficult to dispense in combination with the other chambers 320a-d.

In the above embodiment, it is recognized that the first chamber may be set to have more than eight tablets and that direct feed may be used for more than seven tablets. Moreover, while the chambers have been described as having exponentially incremented numbers of tablets, it is appreciated that it may be desirable to fill the chambers with numbers of tablets which are multiples of seven and/or ten, in view of the fact that most prescriptions comprise a number of tablets in a multiple of seven or ten. Moreover, the number of tablets designated for a particular chamber can be altered via software or hardware.

FIG. 12 is a flow chart that illustrates the operations performed by a controller to load tablets into a given subchamber i within the chambers 320a-e. It will be appreciated that this process is readily extended to load tablets into each subchamber within the chambers 320a-e, and can be used to initially load tablets into the subchambers as well as reload tablets into a subchamber after it has been emptied as described below. The operations begin in block B301 wherein the controller determines whether the subchamber i is empty and thus requires reloading of tablets. If not, the operation returns to wait until this condition is satisfied. If so, the operations continue to blocks B303 and B305. In block B303, the controller controls actuation of the gates of the feed channel (via electrical signals supplied thereto) to define a feed path from the counter to the circular chamber that includes subchamber i. It also controls rotation of this circular chamber (via electrical signals supplied to actuation mechanism 352) such that subchamber i is oriented vertically and tablets supplied thereto will pass through the opening in the outside wall of the circular chamber into the subchamber i. In block B305, the controller starts the feed of tablets into the counter and into the feed channel to initiate the fill operation for the subchamber i. The operations then continue to block B307.

In block B307, the controller monitors the count value output by the counter to determine whether this count value is less than the desired count value (which is the number of tablets to be loaded into the subchamber i). When this operation fails (the count value output by the counter is equal to the desired count value), the operations continue to blocks B309 and B311.

In block B309, the controller terminates the feed of tablets into the counter and into the feed channel to terminate the fill operation for the subchamber i.

In block B311, the controller controls actuation of the gates of the feed channel (via electrical signals supplied thereto) to define a feed path from the counter to the fifth chamber 320e (e.g., overflow chamber), thereby removing the supply path to the subchamber i. This terminates the fill operation for subchamber i after loading the desired number of tablets into the subchamber i. Any extra tablets that may be fed into the counter are stored in the fifth chamber 320e (e.g., overflow chamber).

It will be appreciated that the circular chambers 320a-e as described above provide logical groups of tablet storage containers (e.g., the group of three subchambers that make up a given circular chamber), wherein each group is associated with a given number of tablets. This feature enables high speed dispensing operations by selectively emptying one or more of the tablet storage containers that has been filled with the associated number of tablets.

In the exemplary embodiments described above, only one of the storage containers of a particular group is filled at a time, and one or more of the storage containers of the particular group is emptied at a time. These features provide for simple and efficient operation. Moreover, it is preferred that one of the storage containers of a particular group be capable of being filled simultaneously while another storage container of the particular group is emptied. This feature provides for decreased delays in filling the storage containers that would otherwise result in the event that such operations are performed sequentially.

It will be appreciated that the multi-chamber cell 316 as described above may be readily adapted for use in a multi-cell tablet dispensing system (FIG. 10). In this configuration, the cell is realized by a multi-chamber cell 316 and supporting elements as described above with respect to FIGS. 11 through 13. From the above multi-cell system embodiments, is understood that various other configurations of a multi-cell system may be implemented.

Turning now to FIGS. 13A through 13D, another embodiment of a dispensing system 401 for tablets is shown. The system 401 generally includes many of the features described above, including a feeder 14′ and a counter 18′. The system 401 also includes a cell 402 having four primary chambers 404A, 404B, 404C, 404D for storing tablets therein. A direct feed channel 406 is also provided for automatic feed-through of individually counted tablets in a manner which bypasses the chambers of the cell.

According to a preferred aspect of the invention, each chamber (404A, 404B, 404C, 404D) preferably includes a plurality of subchambers (not shown) for storing tablets therein. In a preferred embodiment, the chambers are generally circular, with the subchambers defined by sectors formed by radially extending walls about a central hub as described above. The chambers (404A, 404B, 404C, 404D) are preferably mounted for individual mechanical rotational movement by a motorized actuation mechanism (not shown). The chambers (404A, 404B, 404C, 404D) have upper and lower apertures which permit tablets to be received into the chamber and dispensed therefrom. When a subchamber is oriented in a first direction, e.g., vertically upwards, the subchamber is positioned to receive tablets fed through its opening. When a subchamber is oriented vertically downwards, the subchamber is oriented to empty its tablet contents via its opening into the discharge chute 408.

Upon receiving an input for dispensing a certain number of tablets, one or more subchambers of the cell are emptied of their contents (e.g., by rotation of the chamber(s)). The tablets that are emptied from such subchamber(s) pass through the discharge chute 408 into the tablet container that is being filled. If necessary, tablets are automatically fed into the direct feed channel 406 to complete the required number of tablets.

After (or during) one or more dispensing operations, tablets are fed from the feeder 14′ to a funnel 411. The funnel 411 directs the tablets supplied thereto to the input of the counter 18′. The output of the counter 18′ is directed to a feed channel network 410 that has two feed channels. The tablets passing through the counter 18′ are selectively routed to one the two feed channels by a transfer gate (not shown). The feed channels have respective release gates 412A, 412B that are selectively open or closed (in the direction of the arrow 414) to block the flow of tables through the two feed channels. Preferably, the release gates 412A, 412B are controlled by a rack and pinion interface (or other mechanical drive mechanism) that closes one of the release gates while opening the other release gate. In this manner, only one of the release gates 412A, 412B is fully open at any point in the fill operations of the cell 402. Note that the feed channels can be used as an intermediate tablet storage container for tablets prior to release via the respective release gate into the desired subchamber of the cell 402.

The tablet counter 18′ and the two-channel feed network 410 are mounted onto an arm 416 that is mechanically rotated about a pivot point 418 by an electric motor (not shown) under control of a controller (not shown). The rotation of the arm 416 translates the counter 18′ and the two-channel feed network 410 (in the XY plane) such that the release gates 412A, 412B of the network 410 are positioned over the desired pair of upper apertures of the cell 402. Position sensors 420 are used to provide feedback to the controller such that it can automatically identify the rotation position of the arm 416 (and thus the position of the release gates 412A, 412B). There are four desired positions for the arm 16, including:

position 1—one feed channel feeds the subchambers of the primary chamber 404A, and the other feed channel feeds the subchambers of the primary chamber 404B;

position 2—one feed channel feeds the subchambers of the primary chamber 404B, and the other feed channel feeds the subchambers of the primary chamber 404C;

position 3—one feed channel feeds the subchambers of the primary chamber 404C, and the other feed channel feeds he subchambers of the primary chamber 404D; and

position 4—one feed channel feeds the subchambers of the primary chamber 404D, and the other feed channel feeds the direct feed channel 406.

With the arm 414 (and thus the counter 416 and the release gates 412A, 412B) placed in its desired position, the feeder 14′ supplies tablets to the funnel 411. While such tablets are supplied to the funnel 411, the counter 18′, transfer gate and release gates 412A, 412B are operated under control of the controller to count out and direct a desired number of tablets through either one of the two feed channels for supply to one of the subchambers of the cell (or to the direct feed channel 406) as desired.

After a subchamber is filled with the appropriate number of tablets, it is possible that an additional tablet will have already been fed by the feeder 14′ to the counter 18′, but not yet counted. As such, the tablet will be stored within one of the two feed channels. The controller can maintain a count of such tablets and use such tablets in refilling another subchamber.

Preferably, the counter 18′ is fed with a supply of tablets, one at a time, from a tilted rotating tablet supply feeder 14′ as shown. In this configuration, the supply feeder 14′ preferably is mounted on the same pivoting arm 416 as the counter 18′ such that there is no relative movement therebetween. As shown in FIGS. 13B1 and 13B2, the supply feeder has three parts 451, 453, 455. The first part 451 is a cylinder (preferably formed from transparent plastic material) with an insert 457 realized by magnetic material (such as iron or stainless steel) that is integrated into an end wall 459 of the cylinder. The second part 453 is a removable cover that fits snuggly over the open end of the cylinder 451. The inside surface of the cover 453 has a wedge-shaped opening 461 disposed near its edge as shown in FIG. 13C. The cylinder 451 and the removable cover 453 provide a primary chamber 463 for holding tablets therein. The wedge-shaped opening 461 leads to a secondary chamber 465 for holding tablets therein. The secondary chamber 465 is defined by the cover 453 and has a frusto-conical wedge shape that is displaced radially with respect to the rotational axis 471 of the feeder 14′ as shown. The secondary chamber 465 leads to a tertiary chamber 467 disposed along the rotational axis 471. The tertiary chamber 467 leads to a supply tube 473 that extends to the funnel 411. The tertiary chamber 467 and supply tube 473 form the third part 455 of the supply feeder. Preferably, the tertiary chamber 467 is formed as a compartment of the supply tube 473 and thus has the same diameter as that of the supply tube 473 as shown. The area of the wedge-shaped inlet 461 of the secondary chamber 465 may be user adjustable (for example, by providing a user-rotatable surface that blocks a variable amount of the inlet 461 into the secondary chamber 465 as it is rotated). Preferably, the volume of the primary chamber 463 is greater than the volume of the secondary chamber 465, and the volume of the secondary chamber 465 is greater than the volume of the tertiary chamber 467. Moreover, the area of the inlet 461 into the secondary chamber 465 is preferably greater than the area of the outlet from the tertiary chamber 467 into the supply tube 473. These features provide sequential feeding of tablets down the feed tube during rotation of the tilted tablet feeder mechanism as described below.

An electric motor 475 is provided that rotates an output shaft 477. A permanent magnet 479 is affixed to the end of the output shaft 477. The magnetic insert 457 integral to the end wall of the cylinder 451 is removably mated to the magnet 479. The rotational axis of the feeder 14′ is oriented such that is tilted downward as best shown in FIG. 13A. Preferably, the angle of the tilt between the rotational axis and the horizontal plane (the XY plane) is between 5 and 20 degrees, but it may extend greater than 20 degrees. This tilt angle may be varied to control the throughput rate of the tablets flowing through the chambers and out the supply tube 473. Larger tilt angles provide for greater throughput rates. Note that the tilt angle may be adjusted during a given counting and dispensing operation to vary the throughput of the tablets supplied to the counting and dispensing apparatus.

During operation, a supply of tablets is added to the primary chamber 463 by the user. The controller starts the electric motor 475, thereby rotating the output shaft 477 and the magnet mount 479, which in turn rotates the feeder 14′ due to the magnet 457 in the end wall 459 of the first part 451 of the feeder. As the feeder mechanism rotates, the primary chamber 463 rotates and the tablets housed therein are mixed. During such mixing, tablets are fed from the primary chamber 463 through the inlet 461 into the secondary chamber 465 and further into the tertiary chamber 467 and into the supply tube 473. The dimensional constraints with respect to the volumes and inlet area of the chambers produce sequential feeding of tablets down the supply tube as described above. Moreover, the size and shape of the volumes and the inlet area of the chambers provided by the three parts 451, 453, 455 may be varied for tablets of different size and shape. Such different size parts may be provided to the user for interchangeability as desired.

Turning now to FIG. 14, distributed control architecture may be used to control a multi-cell tablet counting and dispensing system in accordance with the present invention. Such multi-cell systems typically employ a workstation 1401 (which may be a personal computer, kiosk, or other computer processing system) that interacts with a user to generate the information required to fill a prescription (e.g., patient name, medicament name/dose/quantity, and label information). The workstation 1401 is typically part of a pharmacy management information system that maintains a database of information that generally includes customers, doctors and other health care providers, prescriptions to be filled, prescription that have been filled, etc. In addition, the management computer system typically includes features that enable efficient processing of prescriptions, such as

• • the ability to refill prescriptions for a given customer with just a few keystrokes or mouse clicks;
  • the ability to set up refill control for state requirements;
  • the ability to screen prescriptions against customer records for duplicate prescriptions, drug-disease conflicts, allergies, and patient compliance based on timeliness of refills;
  • the ability to link codes and free text to quickly produce detailed directions;
  • the ability to write unlimited notes regarding patients, doctors, drugs, and prescriptions;
  • the integration of or linking to subsystems that provide for electronic submission of claims/billing;
  • the integration of or linking to subsystems that provide for inventory management and price quotes; and
  • the integration of or linking to subsystems that provide for accounts receivable management.The workstation 1401 is operably coupled to a system controller 1403 over a network communication link 1404 therebetween (which may involve communication over a LAN, WAN or the Internet as is well known in the communication arts). As part of the operations that fulfill a given prescription, the workstation 1401 issues a message (labeled “Dispense Request Message”) to the system controller 1403. The Dispense Request Message identifies a particular medicament name, dose and quantity (and possibly other information) that are necessary to fulfill the given prescription.

In the exemplary embodiment shown, the cells of the multi-cell system are logically organized into groups that are capable of dispensing different medicaments and doses. In response to the reception of the Dispense Request Message, the system controller 1403 identifies one of the cells of the multi-cell system that is capable of dispensing the particular medicament/dose, and issues a command (labeled “Dispense Request Command”) to the local controller 1405_i for that cell (e.g., the local controller 1405₁ of cell 1 as shown). The Dispense Request Command identifies the quantity of the particular medicament/dose that is required to fulfill the prescription. The local controller 1405_i for the selected cell (e.g., the local controller 1405₁ of cell 1) processes the Dispense Request Command and executes a dispensing routine 1409_i that cooperates with the counting/dispensing subsystem 1407_i of the selected cell to dispense the desired quantity of the particular medicament/dose.

As a result of the dispensing routine 1409_i executed by the local controller 1405_i, one or more storage compartments of the cell (sometimes referred to herein as “chambers” or “sub-chambers”) will be emptied, and thus require loading of medicament tablets therein for the next dispensing operation. The local controller 1405_i for the cell monitors such conditions and executes a fill routine 1411_i that cooperates with the counter and fill gates of the cell to load a predetermined number of medicament tablets into the empty storage compartment(s) of the cell. Importantly, the loading operations of the fill routine 1411_i are performed independently of the desired quantity of medicament tablets encoded by a given Dispense Request Command. Moreover, the loading operations of the fill routine 1411_i are preferably performed prior to the execution of the next dispensing routine that requires dispensing of medicament tablets from the empty storage compartment(s). This eliminates any delays that may occur during the execution of this next dispensing routine that would stem from waiting for the fill routine to complete its tablet loading operations.

The dispensing operations are performed for each Dispense Request Message communicated to the system controller 1403. Preferably, such dispensing operations are performed in a parallel manner to provide high throughput dispensing of medicament tablets and efficient fulfillment of prescriptions.

Turning now to FIGS. 15A and 15B, there are shown high level flow charts of exemplary control operations carried out by each local controller 1405_i in order to fill (e.g. load) empty storage compartments with medicament tablets and dispense tablets from such storage compartments. The fill operations (blocks B1501 to B1505) of FIG. 15A are performed in parallel with respect to the dispensing operations (blocks B1507 to B1515) of FIG. 15B in order to eliminate delays that would result from sequential execution of such operations.

The fill operations of FIG. 15A utilize a set of status flags (denoted “Filled status flags”) corresponding to the storage compartments (e.g., “chambers” or “sub-chambers”) of the cell. The Filled status flag corresponding to a given storage compartment indicates whether the given storage compartment is currently empty (Filled status flag=False) or currently filled with a predetermined number of medicament tablets (Filled status flag=True). The fill operations begin in block B1501 by initializing the Filled status flags for the storage compartments of the cell to False. In block B1503, a fill routine (for example, the fill routine of FIG. 13) is executed to fill the empty storage compartments (e.g., those storage compartments with a Filled status flag set to False) with a predetermined number of medicament tablets. Preferably, the Dispensing status flags associated with the storage compartments as described below are used to ensure that the fill operations are performed in a manner that does not interfere with the dispensing operations (described below). Finally, in block B1505, the Filled status flag for the storage compartment(s) filled in block B1503 is set to True to thereby provide an indication that such storage compartments) are full, and the operation returns to block B1503 to fill the emptied storage compartment(s) as they are used.

The dispensing operations of FIG. 15B utilize a set of status flags (denoted “Dispensing status flags”) corresponding to the storage compartment(s) (e.g., “chambers” or “sub-chambers”) of the cell. The Dispensing status flag corresponding to a given storage compartment indicates whether the given storage compartment is currently being used to fulfill a Dispensing Request (Dispensing status flag=True) or not (Dispensing status flag=False). The dispensing operations begin in block B1507 by initializing the Dispensing status flags for the storage compartments of the cell to False. In block B1509, the operations wait until a Dispensing Request command is received, and then continues to block B1511 to process the command. In block B1511, the storage compartment(s) that will be used to fulfill the Dispensing Request are identified and the Dispensing status flag for the identified storage compartment(s) is set to True. Preferably, the storage compartment(s) are selected by a simple computational process that identifies a set of filled storage compartments (with Filled Status flag=True) that together, in combination, store an amount of tablets that equal the desired quantity of tablets. The operations then continue to block B1513 to dispense the desired quantity of tablets from the storage compartments selected in block B1511. Finally, in block B1515, the Dispensing status flag for those chambers used to fill the Dispensing Request is set to False and the operations return to block B1509 to process the next Dispensing Request command.

Advantageously, this control architecture enables the loading/filling and dispensing operations to occur independently and in a parallel fashion. This decreases the time required to perform tablet dispensing because the storage compartments of the cell are preloaded. More specifically, such dispensing time is governed by the time required to open the exit gates to release and empty the tablets from the identified storage compartments. While time is required to refill the emptied storage compartments, the refill occurs after the dispensing operation and presumably while the cell is idle (or possibly servicing other Dispensing Request commands).

There have been described and illustrated herein several embodiments of a tablet dispensing system and a method of dispensing tablets. While particular embodiments of the invention have been described, it is not intended that the invention be limited thereto, as it is intended that the invention be as broad in scope as the art will allow and that the specification be read likewise. Thus, while the gates may be operated with a solenoid, it is appreciated that other means for moving the gates may be used. Also, while swinging gates have been disclosed, it will be appreciated that other types of gates can be utilized. In fact, if vertical space is provided between chambers, vertically moving gates may be utilized, and, in some embodiments, when vertically moving gates are utilized, all gates may be opened simultaneously, and all tablets may be dispensed immediately. In addition, while a particular number of chambers have been shown in each cell, it will be understood that other numbers of chambers may be used. Moreover, in one embodiment, while the number of tablets in each of the chambers is shown to increase with the successively lower located chambers, it is understood that the number of tablets designated for the chambers can be otherwise organized, e.g., a decreasing number of tablets as the chambers are located lower, or with another order to the number of tablets in relation to the location of the chambers. Moreover, while particular distributed control architectures have been described, one skilled in the art will realize that such distributed control architectures may be readily adapted to incorporate well known message buffering and routing techniques and/or pipelined control techniques. Also, while the system is described with respect to dispensing tablets, it will be appreciated that the system and method apply to the dispensing of other relatively small discrete objects. Furthermore, aspects of one embodiment may be combined with aspects of another embodiment. It will therefore be appreciated by those skilled in the art that yet other modifications could be made to the provided invention without deviating from its spirit and scope as claimed.

Claims

1. A method of dispensing tablets, comprising: a) feeding tablets from a hopper to a counter for counting tablets supplied thereto;b) directing counted tablets from the counter to a plurality of storage locations such that each storage location has a discrete number of tablets;c) selecting a number of tablets to be dispensed; andd) dispensing the number of tablets from tablets stored in at least one storage location without counting the tablets;wherein the operations of a) and b) occur prior to the selecting of c) and the dispensing of d).

2. A method according to claim 1, wherein: the dispensing of d) includes releasing the tablets from at least one of the storage locations such that the combined total of the tablets from the at least one storage location is equal to the selected number of tablets to be dispensed.