Patent Description:
Various dispensing cabinets and carts have been developed to assist in the management of medications and other items. For example, <CIT> discloses a dispensing mechanism with a driving gear turned by an actuator causing a segmented belt to be driven, some paddles are integrally formed with segments of the belt or attached to the belt, spaces between paddles form a number of storage compartments, e.g. for blister packs which drop out at the bottom of the dispensing mechanism.

<CIT> and <CIT> disclose similar dispensing mechanisms.

<CIT> discloses linked L-shaped paddles which build a belt with a linking.

<CIT> discloses an inventory cabinet with a dispensing module and a horizontal conveyor made up of a series of conveyor pieces and divider pieces, the conveyor is driven by a motor.

However, improvements are still desired in the reliability of dispensing and tracking of items, and it is also desirable to reduce the amount of space required for item storage and dispensing.

According to independent claim <NUM> a dispensing mechanism comprises a connector for receiving electrical signals from a cabinet in which the dispensing mechanism is installed, an actuator that operates in response to the electrical signals, a non-circular sprocket driven by the actuator, and a belt driven by the sprocket. The belt comprises a plurality of links, and is configured to circulate within a chamber when driven by the actuator. The dispensing mechanism further comprises a plurality of paddles integrally formed with the links of the belt for receiving between pairs of the paddles items to be dispensed, the paddles extending from the belt, wherein each of the paddles is L-shaped in cross section, and wherein the paddles are pinned together in alternating orientations such that each paddle is joined to one adjacent paddle at the corners of the joined L shapes, and each paddle joined to one adjacent paddle at tips of the joined L shapes. The dispensing mechanism also includes a housing defining the chamber and defining an opening at the bottom of the chamber, such that a single item drops from between its respective paddles and through the opening when the segmented belt is incrementally advanced and the paddle supporting the item approaches a vertical orientation due to the advancement of the belt.

Particular embodiments of the invention are set out according to the appended dependent claims <NUM>-<NUM>.

In the following detailed description, the dispensing mechanisms as described in description paragraphs [<NUM>]-[<NUM>] and [<NUM>]-[<NUM>] and corresponding <FIG> and <FIG> are not according to the claimed invention and are for illustrative purposes only. The claimed invention is directed to the dispensing mechanism as described in paragraphs [<NUM>]-[<NUM>] and <FIG>. <FIG> illustrates an example cabinet <NUM> in which the invention may be embodied. Cabinet <NUM> includes various doors <NUM> and drawers <NUM> providing access to compartments for storing items such as medical supplies or medications. For example, supplies such as bandages, swabs, and the like may be stored in unlocked compartments such as may be accessed through one of doors <NUM>. Medications may be stored in individually lockable compartments within drawers such as drawers <NUM>. A computer <NUM> maintains records of the contents of cabinet <NUM>, and may control access to individual compartments. For example, a floor nurse needing to obtain a dose of medication for a hospital patient may enter his or her identification and the medication required into computer <NUM>. Computer <NUM> verifies that the nurse is authorized to remove the medication, and unlocks a particular drawer <NUM> and a particular compartment within the drawer containing the required medication. Computer <NUM> may also control lights that guide the nurse to the correct drawer and compartment, to help ensure that the correct medication is dispensed. In addition, computer <NUM> may communicate with a central computer system that coordinates information from many storage and dispensing devices such as cabinet <NUM>.

While embodiments of the invention are described in the context of stationary cabinet <NUM>, it will be recognized that the invention may be embodied in other kinds of storage devices, for example movable cabinets, carts, storage rooms, and the like. Example dispensing devices are described in the following commonly owned U. Patents and patent applications, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>,, <CIT>, an <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT> to Vahlberg et al. , issued on April <NUM>, <NUM>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, and <CIT>. Embodiments of the present invention may incorporate features from the devices described in these documents, in any workable combination.

In the above scenario, the nurse may be given access to a compartment having a large number of doses of the medication, and he or she may simply remove the number immediately required.

Cabinet <NUM> also includes a return bin <NUM>, into which unused items can be placed, for later return to stock by a pharmacy technician.

When further control and tracking accuracy is required, medications may be placed in a dispensing unit such as dispensing unit <NUM>. Dispensing unit <NUM> includes a restock drawer <NUM> and a dispense drawer <NUM>. Restock drawer includes in turn a number of dispensing mechanisms (not visible in <FIG>) that, under control of computer <NUM>, can dispense single items into dispense drawer <NUM>. Dispense drawer <NUM> can then be opened to retrieve the dispensed items. Restock drawer <NUM> is accessible only by specially-authorized persons, for example for restocking by a pharmacy technician.

<FIG> illustrates dispensing unit <NUM> in more detail, including restock drawer <NUM> and dispense drawer <NUM>. A number of dispensing mechanisms may be installed within restock drawer by <NUM> attaching them to rails <NUM>. Only a few dispensing mechanisms <NUM>, <NUM>, <NUM> are shown in <FIG>. Different types of dispensing mechanisms may be present, depending on the kinds of items to be dispensed, as is discussed in more detail below. The different kinds of dispensers may be of differing sizes, and rails <NUM> may be configured as necessary to accommodate a particular mix of dispensing mechanisms, by fixing rails <NUM> to different sets of hangers <NUM>.

For example, dispensing mechanism <NUM> is a double width mechanism, placed between rails that are two bays wide, while dispensing mechanisms <NUM> and <NUM> are single width mechanisms, placed between rails <NUM> that are connected to adjacent sets of hangers <NUM>. Other sizes of dispensers, for example triple and quadruple widths are also possible.

<FIG> also illustrates that dispense drawer <NUM> and restock drawer <NUM> form a nested pair of drawers. That is, restock drawer <NUM> can slide out of cabinet <NUM> on guides <NUM> for restocking, maintenance, and the like, carrying dispense drawer <NUM> with restock drawer <NUM>. Similarly, dispense drawer <NUM> can slide in and out of restock drawer <NUM> on similar guides not easily visible in <FIG>.

In some embodiments, dispense drawer <NUM> may conveniently serve as a work surface for the user of cabinet <NUM> or a similar device. For example, once an item has been dispensed into dispense drawer <NUM> and the user has opened dispense drawer <NUM> to retrieve the item, the user may use the flat bottom of dispense drawer <NUM> to rest a note pad, computer, or other item he or she may use to document or make notes about the transaction. Dispensing unit <NUM> may include features to facilitate the use of dispense drawer <NUM> as a work surface. For example, the guides or other slide mechanism by which dispense drawer opens may include a detent at the openmost position of dispense drawer <NUM>, to lend stability to dispense drawer <NUM> while it is used as a work surface.

<FIG> is a detail view of a portion of <FIG>, showing that at each hanger <NUM> is an electrical connector <NUM>. Each connector <NUM> connects with a mating connector attached to wiring within a rail <NUM> positioned at the respective hanger <NUM>, supplying power and signals coming from other systems within cabinet <NUM>. Other connectors <NUM> are spaced along the rails, for making electrical connections with the dispensing mechanisms such as dispensing mechanisms <NUM>, <NUM>, and <NUM>. To accomplish the required electrical connections, each rail <NUM> may house a wiring harness, a printed circuit board assembly (PCBA), or the like. Thus, computer <NUM> can communicate individually with any dispensing mechanism within restock drawer <NUM>. Cabling from all of the connectors converges at a circuit board (not visible) at the back of dispensing unit <NUM>, which in turn connects to other electronics within cabinet <NUM> via one or more flexible cables (not visible in <FIG>), which permits dispensing unit <NUM> to slide out of cabinet <NUM> for restocking, maintenance, and the like.

<FIG> illustrates dispensing unit <NUM> fully loaded with seven dispensing mechanisms <NUM>, <NUM> dispensing mechanisms <NUM>, and seven dispensing mechanisms <NUM>, fully populating the available spaces on rails <NUM>. It will be recognized that this arrangement of dispensing units is but one example of many, many arrangements of dispensing units that could be employed. For example, restock drawer <NUM> may not be fully populated with dispensing units. Only one or two different kinds of dispensing mechanisms may be present, or four or more kinds of dispensing units may be present. Different kinds of dispensing units may be present in any workable proportions, and like dispensing units need not be installed next to each other. Example dispensing unit <NUM> can hold up to <NUM> single width dispensing mechanisms (with two additional rails <NUM> installed). One example of this is shown in <FIG>, in which dispensing unit is loaded with <NUM> dispensing mechanisms <NUM>.

Preferably, each dispensing unit can identify itself through its respective connector <NUM>, and computer <NUM> can create a map of the particular arrangement of dispensing units that are installed. Computer <NUM> can also preferably detect the presence of a dispensing unit at any one of the bay positions, through the respective connector <NUM> or via a separate sensor. In addition, each dispensing unit can preferably also communicate to computer <NUM> the kind and quantity of items it contains and stands ready to dispense.

<FIG> is a reverse angle view of a portion of the fully-loaded dispensing unit <NUM> of <FIG>, showing a back panel <NUM> of restock drawer <NUM>. Preferably, both restock drawer <NUM> and dispense drawer <NUM> include latching mechanisms operable by computer <NUM>, to prevent the opening of the drawers at improper times. For example, computer <NUM> may permit restock drawer <NUM> to be opened only when computer <NUM> has received a proper security code from a restocking technician, and may permit dispense drawer <NUM> to be opened only after an item has been dispensed from one of dispensing mechanisms <NUM>, <NUM>, <NUM>. A latching mechanism <NUM> for locking and unlocking restock drawer <NUM> is visible in <FIG>. A similar latching mechanism may be provided inside restock drawer <NUM> for locking and unlocking dispense drawer <NUM>. Also visible in <FIG> are various connectors <NUM> for connecting to other electronics within cabinet <NUM>, for example a power supply, computer <NUM>, or other electronic components through one or more flexible cables (not shown).

The dispensing mechanisms <NUM>, <NUM>, <NUM> may be tailored to the size and type of items to be dispensed, and provide improvements over prior dispensing mechanisms. For example, one prior type of dispensing mechanism used a helical coil, and items to be dispensed were positioned between the coils of the helix. The coil was rotated until an item was advanced beyond the grasp of the coil and was dispensed. This kind of dispenser, although widely and successfully used, is somewhat limited in the shapes and sizes of items that could be dispensed, as the items must be compatible with the pitch and size of the coil.

<FIG> illustrate upper and lower views of dispensing mechanism <NUM> in more detail. Dispensing mechanism <NUM> may be especially useful for dispensing small items such as individual medicine doses packaged in well-known "blister packs", although dispensing mechanism <NUM> may be useful for dispensing may other kinds of items as well.

As is visible in <FIG>, a button <NUM> at the top of dispensing mechanism <NUM> allows a user authorized to access the interior of restock drawer <NUM> to signal computer <NUM>, for example to record the fact that dispensing mechanism <NUM> has been refilled. A light <NUM> enables computer <NUM> to communicate to the user, for example flashing the light to direct the user to restock this particular dispensing mechanism.

As is visible in <FIG>, a connector <NUM>, compatible with connectors <NUM> on rails <NUM>, is positioned to engage one of connectors <NUM> when dispensing mechanism <NUM> is installed in restock drawer <NUM>. Various parts of dispensing mechanism <NUM> collectively constitute a housing that defines an opening <NUM> at the bottom of dispensing mechanism <NUM>, through which items are dispensed. Dispensing mechanism <NUM> may be removably secured to one of rails <NUM> using a snap mechanism, one or more screws, or by another method.

As is shown in <FIG>, example dispensing mechanism <NUM> comprises a dispenser <NUM> and a cassette <NUM>, which are separable. For example, dispenser <NUM> and cassette <NUM> may snap together, may be separable with the removal of one or a small number of screws, or may be reasonably separable in some other way without damage to either dispenser <NUM> or cassette <NUM>. In this way, restocking may be accomplished by replacing a depleted cassette <NUM> with a full cassette <NUM>. A gear <NUM> engages a driving gear (not easily visible in <FIG>) within dispenser <NUM> when cassette <NUM> is assembled to dispenser <NUM>.

Preferably, as will be discussed in more detail below, cassette <NUM> does not contain any active electrical components. All of the active components of example dispensing mechanism <NUM> reside in dispenser <NUM>. For example, an antenna <NUM> can excite a passive memory chip <NUM> in cassette <NUM>, to determine the contents of cassette <NUM> (written into passive memory chip <NUM> when cassette <NUM> was filled at a remote location). If desired, antenna <NUM> can also be used to update the data in passive memory chip <NUM>. This wireless data exchange may use any suitable wireless protocol, for example Near Field Communications (NFC), radio frequency identification (RFID), or another wireless protocol.

Dispenser <NUM> can preferably automatically detect the installation and removal of cassette <NUM>. This automatic detection may facilitate the inventory and tracking of items, and also can help prevent illicit diversion of items. The detection may be accomplished in any suitable way, for example periodic polling using antenna <NUM>, a contact sensor (not shown) that can detect the presence of cassette <NUM> electromechanically, or by another technique.

In other embodiments, a dispensing mechanism in accordance with embodiments of the invention may not have the separable architecture of dispensing mechanism <NUM>, but may be a single unit including space for storing items to be dispense and including an actuator and other components for dispensing items. In other embodiments that do include a cassette, the cassette may include active components, for example a motor or other actuator, light emitters for sensing, or other components.

As are visible in <FIG>, a light emitter <NUM> and two light receivers <NUM> are positioned near the bottom of dispenser <NUM>. In operation, light from light emitter <NUM> reflects from reflective surface <NUM> (visible in <FIG>) and returns to light receivers <NUM>, so long as it is not interrupted by an item being dispensed and falling through the "light curtain" formed across opening. When an item is dispensed through opening <NUM>, it interrupts the light received by either or both of light receivers <NUM>, and dispenser <NUM> can note that an item has in fact been dispensed. If no light interruption is detected despite a command to dispense an item, computer <NUM> may assume that a misfeed or other problem has occurred, or that cassette <NUM> is empty. By using more sophisticated monitoring strategies, accidental dispensing of multiple items may be detected. For example, if two interruptions of the light curtain are detected closely spaced in time, a double feed may be indicated. Emitter <NUM> may be of any suitable type of emitter, and may emit light in any suitable wavelength or combinations of wavelengths. For example, light emitter <NUM> may be a light emitting diode, a laser such as a vertical cavity semiconductor emitting laser (VCSEL) or another kind of light source, and may emit visible light, infrared light, or light in other suitable wavelength bands or combinations of wavelength bands.

In other embodiments, light emitter <NUM> and receivers <NUM> may be on opposite sides of opening <NUM>, so that receivers <NUM> receive light directly from light emitter <NUM> until the light is interrupted by the dispensing of an item.

<FIG> shows a partially cutaway oblique view of dispensing mechanism <NUM>, revealing some internal details of dispenser <NUM>. A motor <NUM> having a right-angle drive turns driving gear <NUM>, which engages gear <NUM> on cassette <NUM> to actuate cassette <NUM>. Motor <NUM> may be, for example, a stepper motor whose angular position can be readily moved incrementally and held. In that case, an item may be dispensed by advancing motor <NUM> by a number of steps known to correspond to one dispensing operation. If the light curtain does not detect that an item is dispensed, motor <NUM> may be advanced further, and if no dispensing is yet detected, an error message may be generated, or it may be assumed that cassette <NUM> is empty. Alternatively, motor <NUM> may be a simple DC or AC motor, in which case dispensing may be accomplished by simply running motor <NUM> until the dispensing of an item is detected, and then shutting off the motor so that motor <NUM> is advanced incrementally as far as is needed. A time limit may be imposed, such that if no dispensing is detected within the time limit with motor <NUM> running, the motor may be shut off and an error message generated.

In other embodiments, an actuator other than a motor may be used. For example, a solenoid or memory metal actuator may provide a reciprocating motion that is used to drive the driving gear within dispenser <NUM> using a ratchet or ratchet-like arrangement. Other kinds of actuators and driving arrangements are possible.

A microprocessor, microcontroller, or similar controlling circuitry may reside within dispenser <NUM>, and may operate the various active components and sensors of dispenser <NUM> in response to high-level commands from a supervisory controller elsewhere within restock drawer <NUM>, or from computer <NUM>. In that case, dispenser <NUM> is considered a "smart" dispenser, because it includes some processing intelligence. However, other architectures are possible. For example, logic signals from a supervisory controller elsewhere within restock drawer <NUM> may operate dispenser <NUM>.

As was discussed above, dispensing mechanism <NUM> may be especially useful for dispensing individual medicine doses such as those commonly packaged in blister packs. <FIG> illustrates a typical blister pack <NUM>. A flat portion <NUM> may be made of cardboard, a stiff plastic, or the like. A plastic bubble-like "blister" <NUM> is laminated to flat portion <NUM>, with a capsule or the like (not visible) confined within blister <NUM>.

<FIG> shows an orthogonal view of cassette <NUM>, with its back cover removed, and showing the internal workings of the cassette. A segmented belt <NUM> is supported between drive shaft <NUM> and idler shaft <NUM>. Drive shaft <NUM> is connected to gear <NUM>, such that belt <NUM> is driven by gear <NUM>, and ultimately by motor <NUM>. Motor <NUM> (and thus belt <NUM>) may be driven in either direction. Paddles <NUM> are integrally formed with segments of belt <NUM>, and circulate within chamber <NUM> as the belt moves. Recesses within drive shaft <NUM> and idler shaft <NUM> (not visible) engage with teeth <NUM> formed on the inner surface of belt <NUM>, providing positive relationship between the angular position of drive shaft <NUM> and the travel of belt <NUM>.

Other arrangements are possible. For example, belt <NUM> could be a continuous belt rather than a segmented belt, and paddles <NUM> could be attached to the belt rather than being integrally formed with it.

The spaces between paddles <NUM> form a number of storage compartments, some of which are filled with blister packs <NUM>. To dispense an item, belt <NUM> is incrementally advanced until the bottommost paddle <NUM> holding an item approaches a vertical orientation, as shown by paddle <NUM>, and the item falls by gravity through opening <NUM> to dispense drawer <NUM>.

While chamber <NUM> is shown as being oriented vertically (being taller than it is wide), this is not a requirement. A dispensing mechanism according to embodiments of the invention may also position a chamber in a horizontal orientation (being wider than it is tall).

<FIG> is an oblique detail view of the upper portion of cassette <NUM>, providing more detail about the construction of cassette <NUM>.

The use of paddles <NUM> in this manner provides the ability to store a large number of items to be dispensed, in comparison with prior cassette designs, for example the prior helical screw dispenser. Example cassette <NUM> uses <NUM> paddles <NUM>, providing storage for up to <NUM> items between paddles <NUM>. More or fewer paddles <NUM> could be used, providing a different number of storage spaces, depending on the sizes of the items to be placed in and dispensed from the cassette. While other dimensions are possible, example cassette <NUM> is approximately <NUM> tall, <NUM> wide, and <NUM> deep, and thus displaces a volume of less than <NUM> cubic centimeters, or about <NUM> cubic centimeters for each item that can be stored in cassette <NUM>. In other embodiments, more items may be stored by placing paddles <NUM> closer together, making paddles <NUM> smaller, or by other miniaturization techniques. For example, in various embodiments, cassette <NUM> may displace, less than <NUM>, less than <NUM>, less than <NUM>, less than <NUM>, or less than <NUM> cubic centimeters for each item stored in cassette <NUM> at full capacity.

In some embodiments, dispensing mechanism <NUM> may include one or more sensors for directly detecting movement of a mechanical component of dispensing mechanism <NUM>. For example, the driving gear within dispenser <NUM> may have holes around its main portion, so that the remaining material between the holes functions as broad spokes. A reflective optical sensor may be provided within dispenser <NUM> that shines light (for example infrared light) onto the driving gear and can detect whether a return reflection is received. Rotation of the gear then results in an alternating signal from the sensor as the reflective "spokes" and the non-reflective holes alternately pass the sensor. A processor or other circuitry within dispenser <NUM> can interpret this signal to verify the motion of the driving gear. This direct measurement provides additional feedback as to the operation of dispensing mechanism <NUM>. For example, if it is verified using the additional sensor that belt <NUM> has moved sufficiently far that an item should be dispensed, but the light curtain sensor does not detect the dispensing of an item, it may be determined that cassette <NUM> is empty, or it may be suspected that an error has occurred.

Other kinds of sensors could be used to directly measure mechanical motion. For example, the passing of paddles <NUM> may be detected by a reflective optical sensor shining light through an opening the wall of chamber <NUM>. Preferably, any active parts of the sensing system reside in dispenser <NUM>, so that cassette <NUM> does not include active electrical components.

<FIG> illustrate upper and lower partially exploded oblique views of dispensing mechanism <NUM>. Dispensing mechanism <NUM> may be especially useful in dispensing vials such vial <NUM> shown in <FIG>having a protruding cylindrical top <NUM>. Vial <NUM> may be used, for example, for storing fluids for loading into a hypodermic syringe for injection into a patient. Other similarly-shaped items may also be dispensed by dispensing mechanism <NUM>.

Referring again to <FIG>, example dispensing mechanism includes a dispenser <NUM> and a cassette <NUM>, which may be easily separable for restocking dispensing mechanism <NUM>.

Preferably, cassette <NUM> does not contain any active electrical components. All of the active components of dispensing mechanism <NUM> reside in dispenser <NUM>. For example, an antenna <NUM> can excite a passive memory chip <NUM> in cassette <NUM>, to determine the contents of cassette <NUM> (written into passive memory chip <NUM> when cassette <NUM> was filled at a remote location). If desired, antenna <NUM> can also be used to update the data in passive memory chip <NUM>. This wireless data exchange may use any suitable wireless protocol, for example Near Field Communications (NFC), radio frequency identification (RFID), or another wireless protocol.

Dispenser <NUM> can preferably automatically detect the installation and removal of cassette <NUM>. This automatic detection may facilitate the inventory and tracking of items, and also can help prevent illicit diversion of items. The detection may be accomplished in any suitable way, for example periodic polling using antenna <NUM>, a contact sensor (not shown) that can detect the presence of cassette <NUM> electromechanically, or by another technique. Dispensing mechanism <NUM> may be removably secured to one of rails <NUM> using a snap mechanism, one or more screws, or by another method.

Although not visible in <FIG>, a light emitter and light receivers are positioned near the bottom of dispenser <NUM>, and operate similarly to light emitter <NUM> and receivers <NUM> described above with respect to dispensing mechanism <NUM>. In operation, light from the light emitter reflects from reflective surface <NUM> (visible in <FIG>) and returns to the light receivers, so long as it is not interrupted by an item being dispensed and falling through the "light curtain" formed across opening <NUM>. When an item is dispensed through opening <NUM>, it interrupts the light received by either or both light receivers, and dispenser <NUM> can note that an item has in fact been dispensed. If no light interruption is detected despite a command to dispense an item, computer <NUM> may assume that a misfeed or other problem has occurred, or that cassette <NUM> is empty. By using more sophisticated monitoring strategies, accidental dispensing of multiple items may be detected. For example, if two interruptions of the light curtain are detected closely spaced in time, a double feed may be indicated.

In other embodiments, the light emitters and receivers may be on opposite sides of opening <NUM>, so that the receivers receive light directly from the light emitters until the light is interrupted by the dispensing of an item.

As is visible in <FIG>, a connector <NUM>, compatible with connectors <NUM> on rails <NUM>, is positioned to engage one of connectors <NUM> when dispensing mechanism <NUM> is installed in restock drawer <NUM>. Although not shown in <FIG>, dispensing mechanism <NUM> may include a button and light similar to button <NUM> and light <NUM> discussed above, for communication between a restocking technician or other user and computer <NUM> of cabinet <NUM>.

<FIG> is a cutaway oblique view of example cassette <NUM>, partially filled with vials <NUM>, and with the top of cassette <NUM> removed. As is visible in <FIG>, cassette <NUM> includes a number of T-shaped vertical channels <NUM> of a shape and size to receive cylindrical tops <NUM> of a number of vials <NUM> and hold the vials in vertical stacks. Vials <NUM> may be, for example, <NUM> vials, having a diameter of about <NUM>, a height of about <NUM>. While other dimensions may be used, example cassette <NUM> is about <NUM> high, <NUM> wide, and <NUM> deep (displacing about <NUM> cubic centimeters), and can hold <NUM> vials of the <NUM> size. Thus, example cassette <NUM> displaces less than <NUM> cubic centimeters for each vial that can be stored in cassette <NUM>. In other uses, <NUM> vials may be used, having a diameter of about <NUM>, in which case cassette <NUM> may hold about <NUM> of the <NUM> vials, for a displacement of less than <NUM> cubic centimeters for each vial that can be stored in cassette <NUM>. Other vial sizes may be used as well. The protruding cylindrical tops of the various vial sizes are preferably similar enough that any compatible size vial can be retained by vertical channels <NUM>. In various embodiments, cassette <NUM> may displace less than <NUM>, less than <NUM>, less than <NUM>, or less than <NUM> cubic centimeters for each vial stored in cassette <NUM> at full capacity.

<FIG> illustrates a lower oblique view of loaded cassette <NUM>, showing spring-loaded latches <NUM>. While cassette <NUM> is separated from dispenser <NUM>, latches <NUM> partially block T-shaped channels <NUM>, preventing vials <NUM> from falling out of cassette <NUM>. Latches <NUM> are connected to a latch release <NUM>, which when actuated in the direction shown, moves latches out of channels <NUM>. When cassette <NUM> is installed in dispenser <NUM>, latch release <NUM> can be moved and restrained, so that vials <NUM> are free to travel down T-shaped channels <NUM>, as is described in more detail below.

<FIG> illustrates a partially-cutaway rear view of the lower portion of dispenser <NUM>. As is visible in <FIG>, a motor <NUM> turns a shaft through right-angle gears <NUM>. Motor <NUM> may be, for example, a stepper motor or a simple DC or AC motor, operated in the manner described above in relation to dispensing mechanism <NUM>. That is, motor <NUM> may be incrementally advanced either by control of the steps of a stepper motor, or by running motor <NUM> only until the dispensing of an item is detected.

In other embodiments, an actuator other than a motor may be used. For example, a solenoid or memory metal actuator may provide a reciprocating motion that is used to drive the gear within dispenser <NUM> using a ratchet or ratchet-like arrangement. Other kinds of actuators and driving arrangements are possible.

<FIG> illustrates a front view of the lower portion of dispenser <NUM>, showing additional details of its operation. A central slotted gear <NUM> is driven directly by right angle gears <NUM>. While a rotation direction is shown for ease of explanation, the choice of rotation direction is arbitrary, and either direction may be used. slotted gear <NUM> drives slotted gears <NUM> and <NUM>. Each of the slotted gears has a T-shaped blind slot <NUM> of a shape and size to receive the cylindrical top of a vial <NUM>. Here, "blind" means that the slot does not continue all the way through the slotted gear.

As the slotted gears rotate, the respective slots <NUM> "take turns" reaching an upward vertical orientation and a downward vertical orientation. For example, the three slotted gears of example dispenser <NUM> are meshed in such a way that one of the T-shaped slots reaches the upward vertical orientation for every <NUM> degrees of rotation of central slotted gear <NUM>. If different numbers of slotted gears are present, then a different angular separation of the gear positions may be used, but preferably slots <NUM> reach the downward vertical orientation at evenly spaced angular intervals of the driving gear <NUM>.

When one of the slots reaches its upward vertical orientation and at least one vial is present in the corresponding T-shaped vertical channel of cassette <NUM> (not shown), the vial is free to drop into the T-shaped blind slot <NUM> of the respective slotted gear. In <FIG>, slotted gear <NUM> has just received a vial <NUM> in this manner. Slotted gear <NUM> has previously received a vial <NUM>. As the gears continue to turn, the slot in slotted gear <NUM> approaches its downward vertical orientation. When the downward vertical orientation is reached, vial <NUM> will be free to drop through opening <NUM> into dispense drawer <NUM>. Slot <NUM> of slotted gear <NUM> is approaching its upward vertical orientation, to receive another vial, if one is present. Thus, the vials in cassette <NUM> can be dispensed one by one.

In some embodiments, dispensing mechanism <NUM> may include one or more sensors for directly detecting movement of a mechanical component of dispensing mechanism <NUM>. For example, the driven gear within dispenser <NUM> may have holes around its main portion, so that the remaining material between the holes functions as broad spokes. A reflective optical sensor may be provided within dispenser <NUM> that shines light (for example infrared light) onto the driving gear and can detect whether a return reflection is received. Rotation of the gear then results in an alternating signal from the sensor as the reflective "spokes" and the non-reflective holes alternately pass the sensor. A processor or other circuitry within dispenser <NUM> can interpret this signal to verify the motion of the driven gear. This direct measurement provides additional feedback as to the operation of dispensing mechanism <NUM>. For example, if it is verified using the additional sensor that the gear has moved sufficiently far that an item should be dispensed (<NUM> degrees in the example embodiment), but the light curtain sensor does not detect the dispensing of an item, it may be determined that cassette <NUM> is empty, or it may be suspected that an error has occurred.

Other kinds of sensors could be used to directly measure mechanical motion. For example, the teeth of slotted gear <NUM> or <NUM> may be visible to a reflective optical sensor shining light through an opening the wall of dispenser <NUM>, and the rotation of the slotted gears may be detected by monitoring the passing of the individual gear teeth. Preferably, any active parts of the sensing system reside in dispenser <NUM>, so that cassette <NUM> does not include active electrical components.

<FIG> illustrate upper and lower views of dispensing mechanism <NUM> in more detail. Dispensing mechanism <NUM> may be especially useful for dispensing cylindrical items such as syringes, although dispensing mechanism <NUM> may be useful for dispensing other similarly-shaped items as well.

Example dispensing mechanism <NUM> comprises a dispenser <NUM> and a cassette <NUM>, which are separable. For example, dispenser <NUM> and cassette <NUM> may snap together, may be separable with the removal of one or a small number of screws, or may be reasonably separable in some other way without damage to either dispenser <NUM> or cassette <NUM>. In this way, restocking may be accomplished by replacing a depleted cassette <NUM> with a full cassette <NUM>.

As is visible in <FIG>, a connector <NUM>, compatible with connectors <NUM> on rails <NUM>, is positioned to engage one of connectors <NUM> when dispensing mechanism <NUM> is installed in restock drawer <NUM>. Dispenser <NUM> defines an opening <NUM> at the bottom of dispensing mechanism <NUM>, through which items are dispensed. Dispensing mechanism <NUM> may be removably secured to one of rails <NUM> using a snap mechanism, one or more screws, or by another method.

A light emitter <NUM> and two light receivers <NUM> are positioned near the bottom of dispenser <NUM>. In operation, light from light emitter <NUM> reflects from a reflective surface of dispenser <NUM> (not visible in <FIG>, but opposite light emitter <NUM> and receivers <NUM>) and returns to light receivers <NUM>, so long as it is not interrupted by an item being dispensed and falling through the "light curtain" formed across opening <NUM>. When an item is dispensed through opening <NUM>, it interrupts the light received by either or both of light receivers <NUM>, and dispenser <NUM> can note that an item has in fact been dispensed. If no light interruption is detected despite a command to dispense an item, computer <NUM> may assume that a misfeed or other problem has occurred, or that cassette <NUM> is empty. By using more sophisticated monitoring strategies, accidental dispensing of multiple items may be detected. For example, if two interruptions of the light curtain are detected closely spaced in time, a double feed may be indicated. Emitter <NUM> may be of any suitable type of emitter, and may emit light in any suitable wavelength or combinations of wavelengths. For example, light emitter <NUM> may be a light emitting diode, a laser such as a vertical cavity semiconductor emitting laser (VCSEL) or another kind of light source, and may emit visible light, infrared light, or light in other suitable wavelength bands or combinations of wavelength bands.

A clear window <NUM> may be provided, so that a user can see the contents of cassette <NUM>.

Although not shown in <FIG>, a button and light similar to button <NUM> and light <NUM> discussed above, for communication between a restocking technician or other user and computer <NUM> of cabinet <NUM>.

<FIG> shows an oblique view of dispenser <NUM> with some parts removed, revealing internal details of the operation of dispenser <NUM>. A cable <NUM> connects a first circuit board <NUM> with a second circuit board <NUM>, to which a motor <NUM> is connected. Motor <NUM> may be, for example, a stepper motor whose angular position can be readily moved incrementally and held. In that case, an item may be dispensed by advancing motor <NUM> by one rotation. If the light curtain does not detect that an item is dispensed, motor <NUM> may be advanced further, and if no dispensing is yet detected, an error message may be generated, or it may be assumed that cassette <NUM> is empty. Alternatively, motor <NUM> may be a simple DC or AC motor, in which case dispensing may be accomplished by simply running motor <NUM> until the dispensing of an item is detected, and then shutting off the motor. A time limit may be imposed, such that if no dispensing is detected within the time limit with motor <NUM> running, the motor may be shut off and an error message generated.

Motor <NUM> turns a cam <NUM> in the direction shown, the function of which is explained in more detail below.

As was discussed above, dispensing mechanism <NUM> may be especially useful for dispensing syringes or other similarly-shaped items. <FIG> illustrates a typical syringe <NUM> of a kind that may be dispensed by dispensing mechanism <NUM>. Syringe <NUM> has a main barrel <NUM> configured to hold a quantity of a serum or other liquid, and a reduced diameter portion <NUM> configured to accept a hypodermic needle or the like. In some embodiments, the outer diameter of main barrel portion may be about <NUM>, and the overall length of syringe <NUM> may be in keeping with the capacity of syringe <NUM>. For example, a syringe <NUM> configured to hold <NUM> of liquid may have an overall length of about <NUM>, while a syringe <NUM> configured to hold <NUM> of liquid may have an overall length of about <NUM>. These dimensions are given only as examples, and syringes or other items having different sizes may be used in embodiments of the invention.

<FIG> illustrate cassette <NUM> with certain outer panels removed, and revealing internal details of cassette <NUM>. In <FIG>, cassette <NUM> is empty, and in <FIG>, cassette <NUM> contains a number of syringes <NUM>. An angled floor <NUM> of cassette <NUM> and an angled moveable guide <NUM> serve to funnel syringes <NUM> toward the lowest part <NUM> of cassette <NUM>, to be dispensed in the manner described below. While other dimensions are possible, example cassette <NUM> is about <NUM> high, <NUM> deep, and <NUM> wide, and thus displaces an overall volume of less than <NUM> cubic centimeters, and can hold up to <NUM> or more syringes <NUM>. Cassette <NUM> thus displaces less than <NUM> cubic centimeters for each syringe that can be stored in cassette <NUM>. While syringes <NUM> having a <NUM> capacity are shown, cassette <NUM> may be configured to dispense syringes having a smaller overall length by placing a spacer block (not shown) within cassette <NUM>. In various embodiments, cassette <NUM> may displace less than <NUM>, less than <NUM>, less than <NUM>, or less than <NUM> cubic centimeters for each item stored in cassette <NUM> at full capacity.

<FIG> illustrate a cutaway view of portions of dispenser <NUM> and cassette <NUM> and their operation to dispense a syringe. A bottom tray <NUM> of cassette <NUM> defines an opening <NUM> and a ledge <NUM>. A movable slide <NUM> defines a slot in which syringe 2000a is positioned in <FIG>. Slide <NUM> is biased to the left by spring <NUM>, such that syringe 2000a remains suspended by ledge <NUM>. Syringe 2000a is in position to be dispensed, while cassette <NUM> contains additional syringes such as syringe 2000b. Spring <NUM> also ensures that the syringes in cassette <NUM> are not accidentally dispensed when cassette <NUM> is separated from dispenser <NUM>, for example during transport from a central pharmacy to cabinet <NUM>.

When it is desired to dispense a syringe, motor <NUM> (not visible in <FIG>) turns cam <NUM> as shown in <FIG>. Cam <NUM> acts against surface <NUM> of slide <NUM>, moving slide <NUM> to the right, aligning the slot in slide <NUM> with opening <NUM> in bottom tray <NUM> of cassette <NUM>. Syringe 2000a can accordingly drop through opening <NUM> and into dispense drawer <NUM>. Syringe 2000b rolls down angled floor <NUM> into position between slide <NUM> and angled floor <NUM>. Guide <NUM> is force upward by its interaction with slide <NUM>, to jostle any remaining syringes within cassette <NUM>, facilitating their future dispensing.

In <FIG>, cam <NUM> has rotated past its contact with slide <NUM>, allowing spring <NUM> to force slide <NUM> back to its nominal position. Sensor electronics may sense the dispensing of syringe 2000a, or that slide <NUM> is back to its nominal position, and may shut off motor <NUM>, stopping cam <NUM>. Syringe 2000b drops into the slot in slide <NUM>, resting on ledge <NUM>, in preparation for its future dispensing.

In other embodiments, an actuator other than a motor may be used. For example, a solenoid or memory metal actuator may provide a translational motion that is used to directly translate slide <NUM> against spring <NUM>. Other kinds of actuators and driving arrangements are possible.

In some embodiments, dispensing mechanism <NUM> may include one or more sensors for directly detecting movement of a mechanical component of dispensing mechanism <NUM>. For example, slide <NUM> may be generally non-reflective, but may include a reflective sticker placed for detection by a reflective optical when slide <NUM> moves under the action of cam <NUM>. The passing of the reflective sticker, as detected by the sensor, verifies that slide <NUM> has actually moved. A similar effect may be achieved by placing a magnet on slide <NUM> and detecting its passing of a Hall Effect sensor. Similarly, the movement of cam <NUM> could be directly sensed. A processor or other circuitry within dispenser <NUM> can interpret a signal produced by the sensor to verify the motion of the slide or cam. This direct measurement provides additional feedback as to the operation of dispensing mechanism <NUM>. For example, if it is verified using the additional sensor that slide <NUM> has moved sufficiently far that an item should be dispensed, but the light curtain sensor does not detect the dispensing of an item, it may be determined that cassette <NUM> is empty, or it may be suspected that an error has occurred.

<FIG> illustrates an electrical block diagram of dispensing unit <NUM>, in accordance with embodiments of the invention. Among other components, dispensing unit <NUM> includes a main PCBA <NUM>, and a number of rail assemblies <NUM>, each of which includes a respective PCBA. Only one generic dispensing mechanism <NUM> is shown, but it will be recognized that a number of dispensing mechanisms such as dispensing mechanisms <NUM>, <NUM>, and <NUM> may be present. Each dispensing mechanism may have its own PCBA <NUM>.

<FIG> illustrates a more detailed electrical block diagram of restock drawer <NUM> main PCBA <NUM>, in accordance with embodiments of the invention. Main PCBA <NUM> include a microcontroller <NUM>, as well as various sensing and communication circuitry, and connections <NUM> for connection to rail assemblies <NUM>.

<FIG> illustrates a more detailed electrical block diagram of a dispenser PCBA <NUM>, in accordance with embodiments of the invention. In this example, the dispenser includes a microcontroller <NUM>, and the dispenser represented is a "smart" dispenser. Dispenser PCBA <NUM> also includes various power and communication circuitry, driver circuitry for a motor, a wireless communication interface and antenna, various other sensors, and other components, many of which may be described above in relation to dispensers <NUM>, <NUM>, and <NUM>.

<FIG> illustrate a dispensing mechanism <NUM> in accordance with other embodiments of the invention. Dispensing mechanism <NUM> is similar in some ways to dispensing mechanism <NUM> described above, and may be especially useful for dispensing small items such as individual medicine doses packaged in well-known "blister packs" such as blister pack <NUM>, although dispensing mechanism <NUM> may be useful for dispensing may other kinds of items as well. Like dispensing mechanism <NUM>, dispensing mechanism <NUM> may include one or more buttons or lights, and may have an internal processor that controls the operation of dispensing mechanism <NUM>. Dispensing mechanism <NUM> includes a connector <NUM>, compatible with connectors <NUM> on rails <NUM> and positioned to engage one of connectors <NUM> when dispensing mechanism <NUM> is installed in restock drawer <NUM>. Various parts of dispensing mechanism <NUM> collectively constitute a housing that defines an opening <NUM> at the bottom of dispensing mechanism <NUM>, through which items are dispensed. Dispensing mechanism <NUM> may be removably secured to one of rails <NUM> using a snap mechanism, one or more screws, or by another method.

As are visible in <FIG>, one or more light emitters <NUM> and light receivers <NUM> are positioned near the bottom of dispenser <NUM>. In operation, light from light emitters <NUM> reflects from reflective surface <NUM> (visible in <FIG>) and returns to light receivers <NUM>, so long as it is not interrupted by an item being dispensed and falling through the "light curtain" formed across opening. When an item is dispensed through opening <NUM>, it interrupts the light received by any of light receivers <NUM>, and dispenser <NUM> can note that an item has in fact been dispensed. If no light interruption is detected despite a command to dispense an item, computer <NUM> may assume that a misfeed or other problem has occurred, or that cassette <NUM> is empty. By using more sophisticated monitoring strategies, accidental dispensing of multiple items may be detected. For example, if two interruptions of the light curtain are detected closely spaced in time, a double feed may be indicated. Emitter <NUM> may be of any suitable type of emitter, and may emit light in any suitable wavelength or combinations of wavelengths. For example, light emitter <NUM> may be a light emitting diode, a laser such as a vertical cavity semiconductor emitting laser (VCSEL) or another kind of light source, and may emit visible light, infrared light, or light in other suitable wavelength bands or combinations of wavelength bands. In other embodiments, surface <NUM> may be non-reflective, for example black, and the dispensing of an item may be detected by noting an increase in the intensity of light reaching receivers <NUM>, rather than a decrease, as light is reflected from the item being dispensed.

In other embodiments, light emitters <NUM> and receivers <NUM> may be on opposite sides of opening <NUM>, so that receivers <NUM> receive light directly from light emitters <NUM> until the light is interrupted by the dispensing of an item.

<FIG> shows an oblique view of dispensing mechanism <NUM> with some parts removed, revealing some internal details of dispenser <NUM>. A motor <NUM> having a right-angle drive turns driving gear <NUM>, which engages gear <NUM> on cassette <NUM> to actuate cassette <NUM>. Motor <NUM> may be, for example, a stepper motor whose angular position can be readily moved incrementally and held. In that case, an item may be dispensed by advancing motor <NUM> by a number of steps known to correspond to one dispensing operation. If the light curtain does not detect that an item is dispensed, motor <NUM> may be advanced further, and if no dispensing is yet detected, an error message may be generated, or it may be assumed that cassette <NUM> is empty. Alternatively, motor <NUM> may be a simple DC or AC motor, in which case dispensing may be accomplished by simply running motor <NUM> until the dispensing of an item is detected, and then shutting off the motor so that motor <NUM> is advanced incrementally as far as is needed. A time limit may be imposed, such that if no dispensing is detected within the time limit with motor <NUM> running, the motor may be shut off and an error message generated.

<FIG> shows an orthogonal view of cassette <NUM>, with its back cover removed, and showing the internal workings of the cassette. A segmented belt <NUM> is supported between drive shaft <NUM> and idler shaft <NUM>. Drive shaft <NUM> is connected to gear <NUM>, such that belt <NUM> is driven by gear <NUM>, and ultimately by motor <NUM>. Motor <NUM> (and thus belt <NUM>) may be driven in either direction. Paddles <NUM> are integrally formed with segments of belt <NUM>, and form links in belt <NUM>. Paddles <NUM> circulate within chamber <NUM> as belt <NUM> moves. A sprocket <NUM> turns with drive shaft <NUM> to drive belt <NUM>, providing positive relationship between the angular position of drive shaft <NUM> and the travel of belt <NUM>.

Sprocket <NUM> is non-circular. That is, its cross section taken perpendicular to its axis of rotation is not circular. In the example of <FIG>, sprocket <NUM> has a square cross section.

<FIG> shows sprocket <NUM> and several paddles in a partially exploded view. Sprocket <NUM> is outlined in dashed lines <NUM> to show its square cross section. Particular paddles 2904a, 2904b, 2904c, and 2904d have been moved from their assembled positions, for clarity of explanation. Each of paddles 2904a-2904d is L-shaped. Paddles 2904a and 2904b join together, for example using pins, at the tips <NUM> of their L shapes, and paddles 2904b and 2904c join together at the corners <NUM> of their L shapes. Similarly paddles 2904a and 2904e are joined at their corners <NUM>, and paddles 2904d and 2904f are joined at their corners <NUM>. Thus, the paddles are joined together in alternating orientation along the length of belt <NUM>.

This arrangement allows the adjacent pairs of paddles defining compartments for holding items to be dispensed to remain closer together as they traverse the top of cassette <NUM> than if sprocket <NUM> were round. The spacing between paddles 2904c and 2904d is labeled "D" in <FIG>. The paddles do not necessarily maintain parallelism through their traversal of the top of cassette <NUM>, but remain closer than if sprocket <NUM> were round. This arrangement may reduce the possibility of jamming of the cassette mechanism.

Referring again to <FIG>, a spring-loaded idler <NUM> maintains tension on belt <NUM>, and takes up the unevenness of the travel of belt <NUM> over square sprocket <NUM>.

The use of paddles <NUM> in this manner provides the ability to store a large number of items to be dispensed, in comparison with prior cassette designs, for example the prior helical screw dispenser. Example cassette <NUM> uses <NUM> pairs paddles <NUM>, providing storage for up to about <NUM> items between paddles <NUM>. More or fewer paddles <NUM> could be used, providing a different number of storage spaces, depending on the sizes of the items to be placed in and dispensed from the cassette. While other dimensions are possible, example cassette <NUM> is approximately <NUM> tall, <NUM> wide, and <NUM> deep, and thus displaces a volume of less than <NUM> cubic centimeters, or about <NUM> cubic centimeters for each item that can be stored in cassette <NUM>. In other embodiments, more items may be stored by placing paddles <NUM> closer together, making paddles <NUM> smaller, or by other miniaturization techniques. For example, in various embodiments, cassette <NUM> may displace, less than <NUM>, less than <NUM>, less than <NUM>, less than <NUM>, or less than <NUM> cubic centimeters for each item stored in cassette <NUM> at full capacity.

<FIG> shows a rear oblique view of cassette <NUM>, and <FIG> shows a magnified view of part of <FIG> illustrate a brake <NUM>. Brake <NUM> is normally engaged, and hinders movement of belt <NUM> when engaged. In this example, teeth <NUM> in brake <NUM> engage with the teeth of gear <NUM> on cassette <NUM>. This may be helpful, for example, during shipment or transport of a full cassette, to prevent intentional or accidental removal of items from cassette <NUM> by turning gear <NUM>.

Preferably, brake <NUM> disengages automatically when cassette <NUM> in installed into dispenser <NUM>. For example, tab <NUM> on brake <NUM> may contact the top of dispenser <NUM> as cassette <NUM> is installed into dispenser <NUM>, lifting brake <NUM> out of engagement with gear <NUM>.

Other measures may be taken to prevent accidental or intentional diversion of items from cassette <NUM>. For example, as shown in <FIG>, openings <NUM> may be provided in back <NUM> and side <NUM> of cassette <NUM>, to accommodate tamper-evident ties that also disable the operation of cassette <NUM>. <FIG> shows cassette <NUM> (with back <NUM> removed) with several ties <NUM> installed. Ties <NUM> may be, for example, plastic "zip" ties or a similar kind of tie, that is not conveniently removable without cutting the tie. Ties <NUM> may be installed when cassette is filled, and not legitimately removed until cassette <NUM> is ready to be installed in a drawer such as drawer <NUM>. If cassette <NUM> arrives at its destination with all of ties <NUM> intact, it may be assumed that no tampering or accidental dispensing has occurred. If any of ties <NUM> is missing or damaged, diversion may be suspected. When a decision is made to install cassette <NUM> in a dispenser or drawer, the restock technician can cut ties <NUM> before installation.

Other kinds of tamper-evident mechanisms may be used as well, instead of or in addition to ties <NUM>.

<FIG> illustrate upper and lower partially exploded oblique views of a dispensing mechanism <NUM>, in accordance with embodiments of the invention. Dispensing mechanism <NUM> is similar in some ways to dispensing mechanism <NUM> described above, and may be especially useful in dispensing vials such vial <NUM> shown in <FIG>having a protruding cylindrical top <NUM>. Vial <NUM> may be used, for example, for storing fluids for loading into a hypodermic syringe for injection into a patient. Other similarly-shaped items may also be dispensed by dispensing mechanism <NUM>.

In other embodiments, a dispensing mechanism in accordance with embodiments of the invention may not have the separable architecture of dispensing mechanism <NUM>, but may be a single unit including space for storing items to be dispense and including the actuator and other components for dispensing items. In other embodiments that do include a cassette, the cassette may include active components, for example a motor or other actuator, light emitters for sensing, or other components.

Although not visible in <FIG>, a light emitter and light receivers are positioned near the bottom of dispenser <NUM>, and operate similarly to light emitter <NUM> and receivers <NUM> described above with respect to dispensing mechanism <NUM>. In operation, light from the light emitter reflects from reflective surface <NUM> (visible in <FIG>) and returns to the light receivers, so long as it is not interrupted by an item being dispensed and falling through the "light curtain" formed across opening <NUM>. When an item is dispensed through opening <NUM>, it interrupts the light received by either or both light receivers, and dispenser <NUM> can note that an item has in fact been dispensed. If no light interruption is detected despite a command to dispense an item, computer <NUM> may assume that a misfeed or other problem has occurred, or that cassette <NUM> is empty. By using more sophisticated monitoring strategies, accidental dispensing of multiple items may be detected. For example, if two interruptions of the light curtain are detected closely spaced in time, a double feed may be indicated. In other embodiments, surface <NUM> may be non-reflective, for example black, and the dispensing of an item may be detected by noting an increase in the intensity of light reaching the receivers, rather than a decrease, as light is reflected from the item being dispensed.

<FIG> is a cutaway oblique view of example cassette <NUM>, partially filled with vials <NUM>, and with the top of cassette <NUM> removed. As is visible in <FIG>, cassette <NUM> includes a number of vertical channels <NUM> of a shape and size to receive a number of vials <NUM> and hold the vials in vertical stacks. In cassette <NUM>, three vertical channels <NUM> are present, and vials <NUM> are <NUM> vials, having a diameter of about <NUM>, and a height of about <NUM>. While other dimensions may be used, example cassette <NUM> is about <NUM> high, <NUM> wide, and <NUM> deep (displacing about <NUM> cubic centimeters), and can hold about <NUM> vials of the <NUM> size. Thus, example cassette <NUM> displaces less than <NUM> cubic centimeters for each vial that can be stored in cassette <NUM>. In other uses, <NUM> vials may be used, having a diameter of about <NUM>, in which case cassette <NUM> may hold a similar number of vials. Other vial sizes may be used as well. Walls <NUM> divide the stacks of vials, and protrusions <NUM> may help constrain the vials by their necks. In various embodiments, cassette <NUM> may displace less than <NUM>, less than <NUM>, less than <NUM>, or less than <NUM> cubic centimeters for each vial stored in cassette <NUM> at full capacity.

Cassette <NUM> also includes a number of open-sided rotatable receivers <NUM> at the bottom of vertical channels <NUM>.

<FIG> illustrates a lower oblique rear view of cassette <NUM>, showing a set of gears <NUM>, each of which is coupled to one of open-sided rotatable receivers <NUM>. Gears <NUM> mesh, so that receivers <NUM> rotate in synchronization.

<FIG> illustrates a partially-cutaway rear view of dispenser <NUM>, and <FIG> illustrates an oblique front view of dispenser <NUM>. Referring to both <FIG>, a motor <NUM> drives a belt <NUM>, which in turn drives gear <NUM>. Motor <NUM> may be, for example, a stepper motor or a simple DC or AC motor, operated in the manner described above in relation to dispensing mechanism <NUM>. That is, motor <NUM> may be incrementally advanced either by control of the steps of a stepper motor, or by running motor <NUM> only until the dispensing of an item is detected. In other embodiments, an actuator other than a motor may be used. For example, a solenoid or memory metal actuator may provide a reciprocating motion that is used to drive the gear within dispenser <NUM> using a ratchet or ratchet-like arrangement. Other kinds of actuators and driving arrangements are possible.

When dispenser <NUM> and cassette <NUM> are engaged, gear <NUM> meshes directly or indirectly with gears <NUM> of cassette <NUM>, to turn open-sided rotatable receivers <NUM>. Referring again to <FIG>, gears <NUM> rotate in synchronization. While a rotation direction is shown for ease of explanation, the choice of rotation direction is arbitrary, and either direction may be used.

As the gears rotate, the respective open sides of receivers <NUM> "take turns" reaching an upward vertical orientation and a downward vertical orientation. For example, the three gears of example cassette <NUM> are meshed in such a way that one of the receivers reaches the upward vertical orientation for every <NUM> degrees of rotation of gears <NUM>. If different numbers of gears are present, then a different angular separation of the gear positions may be used, but preferably receivers <NUM> reach the downward vertical orientation at evenly spaced angular intervals gears <NUM>.

When one of the receivers reaches its upward vertical orientation and at least one vial is present in the corresponding vertical channel of cassette <NUM> (not shown), the vial is free to drop into the respective receiver <NUM>. As the gears continue to turn, the receivers <NUM> alternately reach their upward positions to receive vials, and reach their downward positions to dispense vials. Thus, the vials in cassette <NUM> can be dispensed one by one.

In some embodiments, dispensing mechanism <NUM> may include one or more sensors for directly detecting movement of a mechanical component of dispensing mechanism <NUM>. For example, the driven gear within cassette <NUM> may have holes around its main portion, so that the remaining material between the holes functions as broad spokes. A reflective optical sensor may be provided within dispenser <NUM> that shines light (for example infrared light) onto the driven gear and can detect whether a return reflection is received. Rotation of the gear then results in an alternating signal from the sensor as the reflective "spokes" and the non-reflective holes alternately pass the sensor. A processor or other circuitry within dispenser <NUM> can interpret this signal to verify the motion of the driven gear. This direct measurement provides additional feedback as to the operation of dispensing mechanism <NUM>. For example, if it is verified using the additional sensor that the gear has moved sufficiently far that an item should be dispensed (<NUM> degrees in the example embodiment), but the light curtain sensor does not detect the dispensing of an item, it may be determined that cassette <NUM> is empty, or it may be suspected that an error has occurred.

Other kinds of sensors could be used to directly measure mechanical motion. For example, the teeth of gears <NUM> may be visible to a reflective optical sensor shining light through an opening the wall of dispenser <NUM>, and the rotation of the gears may be detected by monitoring the passing of the individual gear teeth. Preferably, any active parts of the sensing system reside in dispenser <NUM>, so that cassette <NUM> does not include active electrical components.

While cassette <NUM> is shown as having three vertical channels <NUM>, other numbers of channels may be used. For example, an alternate cassette may have two vertical channels, and may be suitable for dispensing <NUM> vials having a diameter of about <NUM>.

Referring again to <FIG>, a hinged flap <NUM> can be seen below rotatable receivers <NUM>. Hinged flap <NUM> may be lightly spring loaded so that it is normally in an upward position, but can be deflected by the weight of a vial being dispensed. Hinged flap <NUM> may serve to absorb some of the energy of a falling vial, and prevent excessive jostling or bouncing of a vial in the dispense drawer. Hinged flap <NUM> may include a ridge <NUM> configured to engage with the neck of a vial being dispensed. Ridge <NUM> may reduce the tendency of a dispensed vial to rotate during dispensing.

<FIG> shows a rear orthogonal view of a lower portion of cassette <NUM>, and illustrates the operation of a brake <NUM>. Brake <NUM> includes gear teeth <NUM>. When cassette <NUM> is installed in dispenser <NUM>, a part of dispenser <NUM> (not shown) pushes rack <NUM> upward, which turns gear <NUM>, and draws brake <NUM> downward, out of engagement with gear <NUM> so that cassette <NUM> can operate to dispense vials or other items. Brake <NUM> may be helpful, for example, during shipment or transport of a full cassette, to prevent intentional or accidental removal of items from cassette <NUM> by turning gears <NUM>.

Other measures may be taken to prevent accidental or intentional diversion of items from cassette <NUM>. For example, as shown in <FIG>, openings <NUM> may be provided in back <NUM>, side <NUM>, and top <NUM> of cassette <NUM>, to accommodate tamper-evident ties that also disable the operation of cassette <NUM>. <FIG> show cassette <NUM> with ties <NUM> installed. Ties <NUM> may be, for example, plastic "zip" ties or a similar kind of tie, that is not conveniently removable without cutting the tie. Ties <NUM> may be installed when cassette is filled, and not legitimately removed until cassette <NUM> is ready to be installed in a drawer such as drawer <NUM>. If cassette <NUM> arrives at its destination with all of ties <NUM> intact, it may be assumed that no tampering or accidental dispensing has occurred. If any of ties <NUM> is missing or damaged, diversion may be suspected. When a decision is made to install cassette <NUM> in a dispenser or drawer, the restock technician can cut and remove ties <NUM> before installation.

<FIG> illustrate upper and lower views of a dispensing mechanism <NUM> in accordance with embodiments of the invention. Dispensing mechanism <NUM> may be especially useful for dispensing cylindrical items such as syringes, although dispensing mechanism <NUM> may be useful for dispensing other similarly-shaped items as well.

The main body of cassette <NUM> may be made of a clear material, so that a user can see the contents of cassette <NUM>.

<FIG> shows an oblique view of dispenser <NUM> with some parts removed, revealing internal details of the operation of dispenser <NUM>.

One or more light emitters and receivers <NUM>, <NUM> may be positioned near the bottom of dispenser <NUM>. In operation, light from light emitters may reflect from a reflective surface of dispenser <NUM> (not visible in <FIG>) and return to the light receivers, so long as it is not interrupted by an item being dispensed and falling through the "light curtain" formed across opening. When an item is dispensed through opening <NUM>, it interrupts the light received by one or more of the light receivers, and dispenser <NUM> can note that an item has in fact been dispensed. If no light interruption is detected despite a command to dispense an item, computer <NUM> may assume that a misfeed or other problem has occurred, or that cassette <NUM> is empty. By using more sophisticated monitoring strategies, accidental dispensing of multiple items may be detected. For example, if two interruptions of the light curtain are detected closely spaced in time, a double feed may be indicated. The one or more light emitters may be of any suitable type of emitter, and may emit light in any suitable wavelength or combinations of wavelengths. For example, a light emitter in an embodiment of the invention may be a light emitting diode, a laser such as a vertical cavity semiconductor emitting laser (VCSEL) or another kind of light source, and may emit visible light, infrared light, or light in other suitable wavelength bands or combinations of wavelength bands. In other embodiments, the surface may be non-reflective, for example black, and the dispensing of an item may be detected by noting an increase in the intensity of light reaching receivers <NUM>, rather than a decrease, as light is reflected from the item being dispensed.

In other embodiments, light emitters and receivers <NUM>, <NUM> may be on opposite sides of opening <NUM>, so that receivers <NUM> receive light directly from light emitters <NUM> until the light is interrupted by the dispensing of an item.

A cable (not visible) couples connector <NUM> directly or indirectly with a circuit board <NUM>, to which a motor <NUM> is connected. Motor <NUM> may be, for example, a stepper motor whose angular position can be readily moved incrementally and held. In that case, an item may be dispensed by advancing motor <NUM> by one rotation. If the light curtain does not detect that an item is dispensed, motor <NUM> may be advanced further, and if no dispensing is yet detected, an error message may be generated, or it may be assumed that cassette <NUM> is empty. Alternatively, motor <NUM> may be a simple DC or AC motor, in which case dispensing may be accomplished by simply running motor <NUM> until the dispensing of an item is detected, and then shutting off the motor. A time limit may be imposed, such that if no dispensing is detected within the time limit with motor <NUM> running, the motor may be shut off and an error message generated.

<FIG> illustrates a cutaway oblique view of cassette <NUM>, and also cam <NUM> (which is part of dispenser <NUM> rather than cassette <NUM>). Cassette <NUM> is formed by two side pieces <NUM> and <NUM>, which cooperate to define a serpentine channel <NUM> between them. A number of syringes <NUM> are disposed in serpentine channel <NUM>, and feed toward the bottom of cassette <NUM> as syringes are dispensed. While other dimensions are possible, example cassette <NUM> is about <NUM> high, <NUM> deep, and <NUM> wide, and thus displaces an overall volume of less than <NUM> cubic centimeters, and can hold up to <NUM> or more syringes <NUM>. Cassette <NUM> thus displaces about <NUM> cubic centimeters for each syringe that can be stored in cassette <NUM>. While syringes <NUM> having a <NUM> capacity are shown, cassette <NUM> may be configured to dispense syringes having a smaller overall length by placing a spacer (not shown) within cassette <NUM>. In various embodiments, cassette <NUM> may displace less than <NUM>, less than <NUM>, less than <NUM>, or less than <NUM> cubic centimeters for each item stored in cassette <NUM> at full capacity.

<FIG> show orthogonal section views of the lower part of cassette <NUM>, as well as cam <NUM>, and their operation to dispense a syringe <NUM>. A bottom <NUM> of cassette <NUM> defines an opening <NUM> and a ledge <NUM>. A movable slide <NUM> defines a slot in which syringe 2000a is positioned in <FIG>. Slide <NUM> is biased to the left by spring <NUM>, such that syringe 2000a remains suspended by ledge <NUM>. Syringe 2000a is in position to be dispensed, while cassette <NUM> contains additional syringes such as syringe 2000b. Spring <NUM> also ensures that the syringes in cassette <NUM> are not accidentally dispensed when cassette <NUM> is separated from dispenser <NUM>, for example during transport from a central pharmacy to cabinet <NUM>.

When it is desired to dispense a syringe, motor <NUM> (not shown in <FIG>) turns cam <NUM> as shown in <FIG>. Cam <NUM> acts against surface <NUM> of slide <NUM>, moving slide <NUM> to the right, aligning the slot in slide <NUM> with opening <NUM> in bottom <NUM> of cassette <NUM>. Syringe 2000a can accordingly drop through opening <NUM> and into dispense drawer <NUM>.

<FIG> shows a cutaway oblique view of a portion of cassette <NUM>, and illustrates the operation of a brake <NUM>. Brake <NUM> includes a hooked lever <NUM>. When cassette <NUM> is disengaged from dispenser <NUM>, hooked lever <NUM> is biased downward by spring <NUM>, so that hooked lever <NUM> hooks into opening <NUM>, preventing motion of slide <NUM>. When cassette <NUM> is engaged with dispenser <NUM>, a feature of dispenser <NUM> (for example pin <NUM> visible in <FIG>) pushes hooked lever <NUM> into the upward position shown, so that slide <NUM> can move freely. Brake <NUM> may be helpful, for example, during shipment or transport of a full cassette, to prevent intentional or accidental removal of items from cassette <NUM> by moving slide <NUM>.

Other measures may be taken to prevent accidental or intentional diversion of items from cassette <NUM>. For example, as shown in <FIG>, which are upper and lower oblique views of cassette <NUM>, openings <NUM> may be provided in top <NUM>, side <NUM>, and bottom <NUM> of cassette <NUM>, to accommodate tamper-evident ties that also disable the operation of cassette <NUM>. <FIG> show cassette <NUM> with ties <NUM> installed. Ties <NUM> may be, for example, plastic "zip" ties or a similar kind of tie, that is not conveniently removable without cutting the tie. Ties <NUM> may be installed when cassette is filled, and not legitimately removed until cassette <NUM> is ready to be installed in a drawer such as drawer <NUM>. If cassette <NUM> arrives at its destination with all of ties <NUM> intact, it may be assumed that no tampering or accidental dispensing has occurred. If any of ties <NUM> is missing or damaged, diversion may be suspected. When a decision is made to install cassette <NUM> in a dispenser or drawer, the restock technician can cut and remove ties <NUM> before installation.

In each of the embodiments described above, one or more light emitters and detectors are used to create a "light curtain" at the bottom of each dispenser, for detecting items being dispensed, or that an item may not have been dispensed when desired. Additional details of example implementations and uses for the light emitters and detectors are given below.

<FIG> schematically illustrates an arrangement of a light curtain, using only one emitter and one detector for simplicity of explanation. A light emitter <NUM> emits light through space <NUM> toward a surface <NUM>. Light emitter <NUM> may be, for example, an infrared light emitting diode (LED) emitting light at a wavelength of about <NUM>, or may be another kind of light emitter. In some embodiments, emitter <NUM> may be an SFH <NUM> infrared LED emitter available from Osram Sylvania having offices in Wilmington, Massachusetts, USA.

Surface <NUM> may be reflective, for example a mirrored or diffuse white surface, so that some of the light reflected from surface <NUM> is directed to a sensor <NUM>. Sensor <NUM> may be, for example, a model VEMT3700F phototransistor available from Vishay Intertechnology of Malvern, Pennsylvania, USA. Sensor <NUM> produces a signal indicating the intensity of light falling on it. In the configuration of <FIG>, the travel of light from emitter <NUM> to surface <NUM> and back to sensor <NUM> is unobstructed, so that sensor <NUM> will produce a signal indicating that it is receiving light.

When an item is dispensed through space <NUM>, the light is interrupted, as shown in <FIG>. For example, vial <NUM> interrupts the light emanating from emitter <NUM> so that it does not reach surface <NUM>, and does not reflect to sensor <NUM>. Some light may scatter from the surface of vial <NUM>, but little will reach sensor <NUM>, and the signal produced by sensor <NUM> in this state indicates that little or no light is reaching sensor <NUM>. In this arrangement, the dispensing of an item is indicated by a decrease in the light detected by sensor <NUM>.

In other embodiments, surface <NUM> may be non-reflective, for example black. This arrangement may be especially useful when the items to be dispensed are themselves highly reflective. For example, <FIG> shows a light curtain having a black surface <NUM>, with no item being dispensed. Surface <NUM> substantially absorbs the light hitting it from emitter <NUM>, and this sensor <NUM> will produce a signal indicating that it is receiving little or no light.

<FIG> illustrates the dispensing of an item between emitter <NUM> and non-reflective surface <NUM>. In this example, a syringe <NUM> is reflective, and scatters light toward sensor <NUM>, so that sensor <NUM> will produce a signal indicating that it is receiving light when syringe <NUM> passes through space <NUM>. In this arrangement, the dispensing of an item is indicated by an increase in the light detected by sensor <NUM>.

In other embodiments, a "transmissive" light curtain may be used, that does not rely on the reflection of light for detecting dispensed items. For example, <FIG> shows an emitter <NUM> and a receiver <NUM> on an opposite side <NUM> of space <NUM> from emitter <NUM>. Receiver <NUM> receives light directly from emitter <NUM>.

<FIG> illustrates the dispensing of an item between emitter <NUM> and receiver <NUM>. In this example, a blister pack <NUM> interrupts the light emanating from emitter <NUM> so that it does not reach receiver <NUM>. In this arrangement, the dispensing of an item is indicated by a decrease in the light detected by sensor <NUM>.

In other embodiments, a combination of these techniques may be used. For example, a sensor may be monitored to detect both increases and decreases in received light.

<FIG> show schematic diagrams of circuitry for an example system having three light emitters and six light receivers. As shown in <FIG>, three emitters <NUM> can be turned on or off, for example by a controller within cabinet <NUM> or within a specific dispenser, using input <NUM>.

As shown in <FIG>, six light receivers in the form of phototransistors <NUM> produce outputs 5902a-5902f indicating the intensity of light being received by the respective phototransistors <NUM>. In this example, each output is a voltage.

<FIG> illustrates the generation of a detection signal from the outputs 5902a-c of three of phototransistors <NUM>. Output 5902a is fed to a comparator 6001a, which compares the voltage of output 5902a with a first reference voltage 6002a. If output 5902a exceeds reference voltage 6002a, then output 6003a goes to a digital "high" value, but is otherwise low.

Similarly, comparator 6001c compares the voltage of output 5902c with a reference voltage 6002c, and produces output 6003c.

Output 5902b is fed to two comparators 6001b and 6001d. Comparator 6001b operates similarly to comparators 6001a and 6001c, producing a "high" output at output 5903b when the voltage of sensor output 5902b exceeds reference value 6002b. However, comparator 6001d operates in the opposite sense, comparing sensor output voltage 5902b with a high reference 6002d. Output 6003d is "high" when output 5902b is below reference voltage 6002d, but is otherwise low.

All of outputs 6003a-d are fed to a quad-input AND gate <NUM>, which produces a "high" detection signal <NUM> only when all four of the inputs are high. That is, detection signal <NUM> is high only when outputs 5902a-c exceed references 6002a-c, and output 5902b is below reference 6002d. With regard to comparators 6001c, this corresponds to the situation shown in <FIG>, where three receivers are receiving light sufficient to exceed a threshold. With regard to the fourth comparator 6001d, reference 6002d may be set high enough that receiver output 5902b normally does not exceed it, but low enough to possibly "see" glinting reflections. The use of two different comparator senses is sometimes called "window" detection.

Detection output <NUM> will normally be high, but will go low when any one or any number of comparators 6001a-d gives a low signal. Output <NUM> may generate an interrupt in a processor coupled to the appropriate dispensing mechanism to signal the dispensing of an item. In other embodiments, detection signal <NUM> may be polled.

The controller may watch for the detection signal immediately after commanding that an item be dispensed, to confirm proper dispensing or to detect a failure to dispense an item.

However, the controller may monitor detection signal <NUM> at other times as well, to detect a detection signal not produced in conjunction with the dispensing of an item. If detection signal <NUM> goes low at such a time, it may be suspected that a diversion attempt is underway, with a finger or tool being inserted into the dispensing mechanism from below. A warning signal may be generated to indicate the suspected diversion or tampering.

Receiver outputs 5902d-f may be processed in a similar way, to provide a second detection signal. Any workable number of emitters and receivers may be used, with any number triggering on a decrease of light reaching the respective receiver or triggering on an increase of light reaching the respective receiver.

For example, in a system similar to the system of <FIG> and <FIG>, using a black surface <NUM> and relying on reflection from an item being dispensed for detection, most or all of the receivers may be configured to generate a detection signal upon an increase of light being received.

Any or all of the reference voltages may be settable by a controller, for calibration purposes. For example, each of the reference voltages may be the output of a respective digitally-controlled potentiometer. The references may be re-calibrated for each dispense request, for example by turning on emitters <NUM> and adjusting the reference voltages to find the tripping point for each comparator <NUM>. Once the tripping point is found, the reference voltage may be re-adjusted to a percentage of the tripping voltage. Preferably, each reference is calibrated individually.

In the claims appended hereto, the term "a" or "an" is intended to mean "one or more. " The term "comprise" and variations thereof such as "comprises" and " comprising," when preceding the recitation of a step or an element, are intended to mean that the addition of further steps or elements is optional and not excluded. It is to be understood that any workable combination of the elements and features disclosed herein is also considered to be disclosed.

Claim 1:
A dispensing mechanism (<NUM>), comprising:
a connector (<NUM>) for receiving electrical signals from a cabinet in which the dispensing mechanism is installed;
an actuator that operates in response to the electrical signals;
a sprocket (<NUM>) driven by the actuator, wherein the sprocket (<NUM>) is square in cross section;
a belt (<NUM>) driven by the sprocket, the belt comprising a plurality of links, and the belt configured to circulate within a chamber when driven by the actuator;
a plurality of paddles (<NUM>) integrally formed with the links of the belt for receiving between pairs of the paddles items to be dispensed, the paddles extending from the belt, wherein each of the paddles (<NUM>) is L-shaped in cross section, and wherein the paddles are pinned together in alternating orientations such that each paddle is joined to one adjacent paddle at the corners of the joined L shapes, and each paddle joined to one adjacent paddle at tips of the joined L shapes; and
a housing defining the chamber and defining an opening (<NUM>) at the bottom of the chamber, such that a single item drops from between its respective paddles and through the opening when the segmented belt is incrementally advanced and the paddle supporting the item approaches a vertical orientation due to the advancement of the belt.