Abstract:
There is provided an automated prescription filling system using a robotic arm in combination with an automatic pharmaceutical dispenser having a plurality of individual pill-counting units, each under the control of its own microprocessor. The automatic pharmaceutical dispensers are modified for use with the robotic arm. Because tablet counting is completely independent of the robotic arm, system throughput is higher than in systems of the prior art. Unlike systems of the prior art, each individual pill-counting unit can be removed from behind the pharmaceutical dispenser so that the system need not be stopped for such service. The fact that counting operations are divorced from robotic arm movements allows the arm movements to be optimized and multiple prescriptions to be processed simultaneously. Controller software optimizes movement of the robotic arm based upon such factors as the fullness of the vial being transported.

Description:
RELATED APPLICATIONS 
     The present invention is a Continuation-in-Part of application Ser. No. 10/105,570, filed Mar. 26, 2002 now abandoned for ROBOTIC ARM AND METHOD FOR USING WITH AN AUTOMATIC PHARMACEUTICAL DISPENSER, and is related to U.S. Pat. Nos. 5,884,806, for DEVICE THAT COUNTS AND DISPENSES PILLS, issued Mar. 23, 1999; 5,907,493, for PHARMACEUTICAL DISPENSING SYSTEM, issued May 25, 1999; and 6,202,923 for AUTOMATED PHARMACY, issued Mar. 20, 2001, all of which are hereby included by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to pharmaceutical dispensers and, more particularity, to a robotic arm for use in cooperation with an automated pharmaceutical dispensing system. 
     BACKGROUND OF INVENTION 
     Automated pharmaceutical dispensing systems are available which automatically count a predetermined number of pills, tablets, capsules, or similar items. The term pill is used hereinafter to designate any pill, tablet, capsule, or similar solid form of pharmaceutical or similar item. It will be recognized that while a pharmacy has been chosen for purposes of disclosure, the inventive system may be applied to many other fields and the invention is not considered limited to the environment chosen for purposes of disclosure. Such systems are disclosed in U.S. Pat. Nos. 5,884,806; 5,907,493; and 6,202,923, all commonly assigned to the assignee of the instant application. In these systems, pills are counted from a reservoir into an output buffer upon command. Once the pills have been counted, an operator empties the buffer contents into a vial or similar container. 
     It is also known in the art to use robotic arms to automate portions of the prescription filling process in an automated pharmacy. U.S. Pat. Nos. 5,812,410, for SYSTEM FOR DISPENSING DRUGS, issued Sep. 22, 1998 to Nicholas Lion, et al, and 5,838,575, for SYSTEM FOR DISPENSING DRUGS, issued Nov. 17, 1998 to Nicholas Lion, both teach a system wherein disposable containers of drugs are mounted vertically in a frame above individual counting units (i.e., base port subunits). Vials may be moved directly under the counting units to receive tablets or capsules counted from the disposable container. However, there is no teaching of a robotic arm or other robotic type manipulator. In some embodiments, vials to receive the pills, tablets or capsules are manufactured within or near the dispensing unit. 
     In contradistinction, the system of the present invention utilizes a robotic arm in combination with a multi-unit, automated pill dispensing unit. Pill counting is performed by individual independently operable pill counting units, each under direct control of an internal microprocessor. This allows pill-counting operations to be performed independently from movements of the robotic arm. While tablets are being counted, the robotic arm may be performing other tasks, such as fetching a labeled vial, moving an unlabeled vial to a labeling station, moving a filled vial from another counting unit to an output station, etc. In addition, no facility for manufacturing vials from plastic sheeting is provided. 
     U.S. Pat. Nos. 6,006,946 and 6,036,812 for PILL DISPENSING SYSTEM were both issued to Jeffery P. Williams, et al, on Dec. 28, 1999 and Mar. 14, 2000, respectively. Both of these patents teach using a robotic actuator for removing cassettes from a shelving unit, transferring the cassettes to a counting station, counting a predetermined number of tablets or capsules from the cassette into a vial, and ultimately returning the cassette to its proper place in the shelving unit and moving the filled vial to an output station. 
     The unit of the present invention, on the other hand, utilizes a robotic arm in combination with a sophisticated automatic pharmaceutical dispensing system wherein tablets or capsules are independently and simultaneously counted in each of the plurality of counting units in the dispensing system. This requires far fewer movements of the robotic arm and thus provides far greater throughput of the system because of the independence of the tablet counting operations from the robotic arm movement. In addition, parallel pill counting operations are possible, further improving system throughput. In the inventive system, no cassettes need be moved from a shelving unit to a counting unit. 
     U.S. Pat. No. 6,176,392 for PILL DISPENSING SYSTEM, issued Jan. 23, 2001 to Jeffery P. Williams, et al, teaches a bottle dispensing system for use in cooperation with the pill dispensing system disclosed in the &#39;812 and &#39;946 WILLIAMS patents described hereinabove. 
     The system of the present invention has no provision for dispensing bottles. 
     U.S. Pat. No. 6,256,967 for INTEGRATED AUTOMATED DRUG DISPENSER METHOD AND APPARATUS, issued Jul. 10, 2001 to Terrance J. Hebron, et al, teaches a system wherein at least one line of machines is provided to fill, label and cap vials of medication for a particular patient. Multiple prescriptions for a patient are grouped and accumulated in unique, patient-specific output bins. 
     The automated system of the present invention provides no facility for grouping various prescriptions for a particular patient, but rather fills each prescription independently. Only after the prescriptions have been inspected are they sent to a packaging area where multiple prescriptions for a single patient are identified and grouped for pickup by the patient. 
     None of these patents, either individually or in combination, anticipates or suggests the automated prescription filling system of the present invention. 
     It is therefore an object of the invention to provide a system using a robotic arm in combination with an automatic pharmaceutical dispenser. 
     It is a further object of the invention to provide a system using a robotic arm in combination with an automatic pharmaceutical dispenser having a plurality of individual, independent, pill-counting units. 
     It is another object of the invention to provide a system using a robotic arm in combination with an automatic pharmaceutical dispenser wherein each individual pill-counting unit has a dedicated microprocessor. 
     It is an additional object of the invention to provide a system using a robotic arm in combination with an automatic pharmaceutical dispenser wherein tablet or capsule counting is performed independently of and simultaneously with the movement of the robotic arm. 
     It is a still further object of the invention to provide a system using a robotic arm in combination with an automatic pharmaceutical dispenser wherein an individual pill-counting unit may be serviced from behind the automatic pharmaceutical dispenser so that normal operation of the robotic arm with other dispensing modules can continue normally. 
     It is an additional object of the invention to provide a system using a robotic arm in combination with an automatic pharmaceutical dispenser wherein replenishment of individual pill-counting units may be performed from behind the automatic pharmaceutical dispenser so that normal operation of the robotic arm with other dispensing modules can continue normally. 
     SUMMARY OF THE INVENTION 
     The present invention provides a robotic arm in combination with one or more automatic pharmaceutical dispensers having a plurality of individual pill-counting units, each under the control of its own microprocessor. Because pill counting is completely independent of the robotic arm, and multiple pill count units may count simultaneously, system throughput is higher than in systems of the prior art. Unlike systems of the prior art, each individual pill-counting unit can be removed from behind the pharmaceutical dispenser so that the system need not be stopped for such service. That is, operation of the robotic arm is not blocked by a technician in front of the dispensing unit. Also, tablets are loaded into the counting units from the rear of the dispenser. The fact that counting operations are divorced from robotic arm movements allows the arm movements to be optimized; multiple prescriptions may be processed simultaneously. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A complete understanding of the present invention may be obtained by reference to the accompanying drawings, when taken in conjunction with the detail description thereof and in which: 
         FIG. 1  is a perspective, schematic view of a first robotic arm implementation of the prior art; 
         FIG. 2  is a perspective, schematic view of a second embodiment of a robotic arm implementation of the prior art; 
         FIG. 3  is a perspective, schematic view of the robotic arm implementation of the invention; 
         FIG. 4   a  is a timing diagram of the robotic arm implementation of  FIG. 1 ; 
         FIG. 4   b  is a timing diagram of the robotic arm implementation of  FIG. 2 ; 
         FIG. 4   c  is a timing diagram of the inventive robotic arm implementation; 
         FIGS. 5   a  and  5   b  are bottom plan and side sectional isometric views, respectively of a vial adapter for use for use in human vial presentation in an automated prescription dispensing system; and 
         FIGS. 5   c  and  5   d  are bottom plan and side sectional isometric views, respectively of a vial adapter for use for use in robotic presentation in an automated prescription dispensing system. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring first to  FIG. 1 , there is shown a perspective, schematic view  100  of a robotic arm  102  used in an automated prescription filling system of the prior art. Robotic arm  102  is equipped with an end effector  104  as is well known in the robotics art. While a robotic arm  102  having an effector  104  is shown for purposes of disclosure, it will be recognized that other suitable robotic mechanisms may be used to accomplish the disclosed vial movement tasks in accordance with the invention. Consequently, the invention is not limited to the robotic arm chosen for purposes of disclosure but covers any robotic mechanism suitable for accomplishing the described vial movement tasks. For simplicity, the term robotic arm is used herein to refer to any such robotic mechanism. 
     A series of shelving units  106  hold cassettes  108  filled with prescription drugs, generally in pill, tablet or capsule form. Each cassette  108  is specifically designed for the type (i.e., the physical form factor) of drug to be dispensed. 
     Under computer control, as discussed in detail hereinbelow, robotic arm  102  moves to a particular cassette  108  on shelves  106 , grasps the cassette  108 , and moves the cassette  108  to a pill counter  110 . Robotic arm  102  then deposits cassette  108  on counter  110 . At any time after the arrival of cassette  108  at counter  110 , tablet counting may commence, the counted tablets being placed in a buffer (not shown). 
     While counting is in process, robotic arm  102  moves to a vial storage location (not shown), grasps a vial  112  and proceeds to a labeling station (not shown). At the labeling station, vial  112  is labeled, either manually or by an automated labeling system as is well known in the pharmacy automation art. 
     Robotic arm  102  then moves vial  112  to a position under discharge chute  114  of pill counter  110 . Once vial  112  is in position, the counted tablets or capsules are released from a buffer (not shown) within counter  110 . Robotic arm  102  then moves filled vial  112  to an output area and places filled vial  112  on an output conveyor (not shown). After depositing filled vial  112  onto the conveyor, robotic arm  102  retrieves cassette  108  from counter  110  and replaces it in its original position on shelves  106 . The robotic arm  102  is then ready to fill the next prescription. 
     Referring now to  FIG. 2 , there is shown a perspective, schematic view  200  of an alternate embodiment of a robotic system used in an automated prescription filling system of the prior art. Pharmaceuticals to be dispensed are stored in a rectangular array of cassette mechanisms  202 . A gantry mechanism  204  rides on tracks  206  disposed adjacent to the array of cassette mechanisms  202 . Gantry  204  allows horizontal movement along the array of cassette mechanisms  202 . 
     A vertical post  208  is mounted on gantry  204 . Mechanism  210  is supported on post  208  and may travel therealong. On mechanism  210  is a horizontal member  212  which is movable towards and away from the array of cassette mechanisms  202 . In effect, the combination of gantry  204 , mechanism  210  moving on post  208 , and horizontal member  212  allows movement along the X, Y and Z axes. 
     Horizontal member  212  is adapted to grasp a vial  112  from a vial storage area and move it into proximity to a selected cassette mechanism  202 . Once vial  112  is in its proper position, a motor  214  having a shaft  216  which is received in cassette mechanism  202 , rotates and dispenses a predetermined number of tablets or capsules from cassette assembly  202  directly into vial  112 . Vial labeling may be performed either before or after vial filling. Once the filled vial  112  is labeled, it is placed on an output conveyor (not shown) and the robot assembly  200  is available to fill the next prescription. Prior art systems like that shown in  FIG. 2  are generally faster than those shown in  FIG. 1 . 
     A pharmacist inspects the vials on the output conveyor and ensures that the correct pharmaceutical has been dispensed. Once satisfied, the pharmacist places a cap on the vial  112 , mates the vial  112  with the correct paperwork (typically a copy of the label that was applied to the vial  112 , as well as other data in the prescription data record and/or patient instructions) and allows the filled, capped vial  112  to proceed to a shipping or other delivery station (not shown). Both types of systems suffer from the fact that the robotic arm is occupied for the entire period that tablets or capsules are being counted. 
     Referring now to  FIG. 3 , there is shown a perspective, schematic view  300  of a robotic arm in accordance with the invention for use with an automated tablet dispensing system. Automated dispensing systems  302  such as those described in U.S. Pat. No. 5,907,493, are well suited for use with an auxiliary robotic arm. Each dispensing system  302  contains an array of dispensing modules (i.e., pill counters)  308 . Such dispensing modules  308  are described in detail in U.S. Pat. No. 5,884,806. 
     Refer now also to  FIGS. 5   a - 5   d . Dispensing modules  308  each have an operator interface that requires the user, not shown, to bring an empty, typically pre-labeled vial  112  to the appropriate dispenser  308  and press release switch actuator  504 . The part of the dispenser  308  that accepts the vial  112  is the vial adapter  500 . This vial adapter  500  has a V-shaped backstop  502  to assist the user in locating the vial  112  against the switch actuator  504  that is located at the apex of the V-shaped backstop. After the switch, not shown, is activated by switch activator  504 , the hopper door, not shown, opens and the contents of the internal buffer, (i.e., the pre-counted tablets), are released into the vial  112 . This human-user interface has one key aspect that is rarely mentioned and is intuitive in nature. When the operator holds the vial  112  in position, it is natural to push the vial into the V notch of the vial adapter, and press the vial in place with a force that is greater than is required to actuate the switch. The switch typically requires only about 300 grams force to actuate. The excess force exerted by a human operator is important when considering differences between a human operator and a robot. 
     A robotic manipulator  304  equipped with an end effector  306  to hold a vial  112  at the correct angle and position in front of a dispenser  308  is programmed to a position in three-dimensional space. Position alone is the defining goal of the robotic manipulator. For example, there is no feedback mechanism present that indicates to a controller that the vial  112  is seated against backstop  502  of vial adapter  500 . It should be noted that the actuation of the dispenser release switch described hereinbelow does not typically provide vial location information of high enough accuracy to precisely position vial  112 . 
     The robotic manipulator  304  is programmed to a location that includes the pressing of the dispenser release switch, not shown, via switch actuator  504 . However, all such simple switches experience both over-travel and hysteresis. Over-travel is the distance the switch actuator  504  moves beyond the point where the switch makes electrical connection. This over-travel of the switch actuator  504  is typically about 0.030 to 0.060 inches. When a human operator presents vial  112  at the dispenser  308 , this over-travel is small enough, and so subtle, that most people do not feel or recognize its existence. However, the over-travel is necessary for the complete engagement and alignment of the vial  112  to the opening  506  to the internal buffer, not shown. The over-travel is always achieved when excess force is applied to the vial  112 . The robotic manipulator, however, is programmed to a position that actuates the switch, but is not necessarily the full stroke of the switch/switch-actuator  504  (including all the over-travel). This difference is significant. In addition, variations in vials  112 , (e.g., vials may be purchased from different manufacturers, or vial size may vary slightly even in vials from the same manufacturer), or operational tolerances in the movement of the robotic arm  304  may exacerbate the problem. 
     Switch hysteresis also becomes important as the dynamics of the settling manipulator can result in a momentary overshoot of the target position, which will actuate the switch but the manipulator may restore to a position further away than anticipated, while the switch remains actuated. 
     These combined effects mean that there can be upwards to a 0.090-inch difference between the actual vial  112  position and the fully seated vial position in the V-shaped backstop  502  of the vial adapter  500 . This distance from the fully seated position is sufficient for small tablets like Zocor®, Synthroid®, and Estradiol® to rest edgewise on the lip of the vial  112  during the buffer release. When the robotic manipulator  304  moves the vial  112  away from the dispenser, such tiny tablets usually fall to the floor. 
     While the percentage of tablets which fall edgewise onto a vial, then fall to the floor, is small, when hundreds of thousands of tablets are handled daily in a refill center, the total number is unacceptable. A lost tablet means that the prescription being filled is short one tablet. 
     One solution to the problem of lost tablets is to funnel or guide the dropping tablets outward into the vial  112 . The round vial adapter opening,  506  (typically about 1.3 inches in diameter) is chosen to minimize any form of constriction to prevent bridging of tablets during release from the output buffer. However, a compromise is necessary whereby some constriction is necessary to divert the tablets released from the output buffer further towards the center of the vial  112 . The first prototypes were a shim or wedge  508  added to the vial adapter  500 ′ ( FIGS. 5   c  and  5   d ). This glued-in piece was tapered to a thin knife-edge on the upper edge of the wedge  508  to eliminate any chance that a tablet could catch or hang at that point. From the top edge, the wedge  508  enlarged to a maximum of approximately 0.115 inch at the midpoint. Because this wedge fits into a round opening  506 , the wedge  508  tapers to zero thickness towards each side. 
     After the contour of the shim or wedge  508  was optimized, several hundred dispensers  308  were modified with the glued in parts. The performance of the system showed a marked improvement (i.e., dropped tablets were significantly reduced) with robotically presented vials  112 . The measured performance was about a ten-fold decrease, to about 0.005% drops. 
     With the success of the initial tests, the mold for the vial adapter  500 ′ was modified to include this feature. 
     One or more automated dispensing systems  302  incorporating the modified vial adapter  500 ′ as shown in  FIG. 5   b  are clustered about a robotic arm  304 . An end effector  306  located at the distal end of robotic arm  304  is adapted to grasp a vial  112  from a vial storage area (not shown). 
     Robotic arm  304 , typically under computer control, moves an empty vial  112  to the discharge region (not shown) of a predetermined dispensing module  308 . Because each dispensing module  308  is typically controlled by its own integral microprocessor, multiple simultaneous counting operations may be conducted independently of the movement of robotic arm  304 . This provides a significant improvement in the utilization of the robotic arm  304 , resulting in much higher throughput from the automated prescription filling system  300 . The motion of the robotic arm  304  may be optimized, even if this results in filling prescriptions out of sequence. 
     In operation, a computer generates commands to both robotic arm  304  and to one or more individual pill-counting modules  308 . Counting modules  308  may independently and simultaneously count several different prescriptions. Robotic arm  304  need only fetch a labeled vial  112 , move to the discharge chute of the proper counting module  308 , discharge the previously-counted tablets into the vial  112 , and move the filled vial  112  to an output area where the filled vial  112  is typically placed onto an output conveyor. As with the prior art systems of  FIGS. 1 and 2 , the filled vials are typically moved to a pharmacist for inspection and capping. 
     Several novel features are incorporated in the control software, not shown, for dispensing modules  308  and robotic arm  304 . Prior to fetching a vial, a vial size determination is made. Again contrasting human operation and robotic operation, when a human presents a vial  112  at the output region of dispenser module  308 , he or she immediately knows if the counted contents at dispensing module  308  fit into the vial  112  presented. When the contents may potentially overflow the vial  112  presented, the operation may be aborted and a larger vial procured. However, in a robotic system, if an incorrect vial  112  is selected and presented for filling, the contents may overflow the vial  112  and be lost. As the overflow may go undetected, not only is product lost, but a customer may receive fewer pills, tablets, or capsules than were ordered and for which he or she paid. 
     In the system of the present invention, a vial size calculation must be made before a vial  112  is presented to ensure that the presented vial  112  will, indeed, accommodate the counted pills in the output buffer of dispensing module  308 . This allows the automated system to compensate when the calculation shows that the contents of the output buffer may not fit into the vial scheduled for presentation. 
     Another novel feature of the control software is that a degree of fullness factor may also be calculated for each vial  112  to be transported. Nearly empty vials  112  may be accelerated to and transported at higher velocities than nearly full vials  112 . Acceleration and travel velocity may, therefore, be optimized for each vial  112  based on the contents thereof. 
     As previously mentioned, dispenser modules  308  are typically grouped on shelves, trays or drawers that may be rearwardly withdrawn so that one or more of the dispensing modules disposed thereupon may be replenished. Were a human operator to present a vial  112  for filling at a dispensing module disposed on a withdrawn shelf, he or she would immediately notice that the desired dispensing module  308  is not physically accessible. The robotic arm  304  has no way of making this determination. Consequently, the controller software includes provisions for placing “on hold” directives to the robotic arm  304  to pick up counted tablets from an unavailable dispenser module  308 . Robotic arm  304  may proceed to service other available dispensing modules  308  while waiting for the withdrawn tray of dispensing modules  308  to again become available. It should be noted, however, that all working dispensing modules  308  on the withdrawn tray may continue to independently count pills while the tray is withdrawn to replenish one or more of the other dispensing modules  308  disposed thereupon. 
     The novel controller software also handles a circumstance where a dispenser module&#39;s  308  contents are exhausted before a full count is placed in its output buffer. The order may be placed on hold pending replenishment of the empty dispensing module  308 . Upon replenishment of the empty dispensing module  308 , counting continues and the controller eventually directs robotic arm  304  to retrieve the counted pills therefrom. 
     Yet another circumstance handled by the controller software concerns prescription orders cancelled after pills have already been counted by a dispensing module  308 . When this circumstance occurs in a human-serviced automated dispensing system, the human simply may fill a vial  112 , and mark the label with “return to stock” or a similar indication. The vial  112  is then set aside for handling in accordance with the particular policy or procedure in place at a particular site. The novel controller software includes features which allow a vial to be automatically labeled “return to stock”, etc., the pills picked up from the dispensing module  308 , and the vial transported to an exceptions area for manual handling. 
     These features, typically unnecessary for human operation of an automated pharmacy dispensing system, are desirable to ensure a smooth flow of prescriptions through the inventive automated system employing robotic arm  304 . 
     Referring now to  FIGS. 4   a ,  4   b  and  4   c , there are shown graphic representations of the steps performed by the robotic arms or equivalent mechanisms in each of the embodiments shown in  FIGS. 1 ,  2  and  3 , respectively. As may been seen in  FIG. 4   a , approximately fifteen steps are required by robotic arm  102  to fill a single prescription.  FIG. 4   b  shows that only about eight movements are required by the gantry mechanism of the prior art system of  FIG. 2 . As was previously stated, the embodiment of  FIG. 2  typically operates more quickly than does the embodiment of  FIG. 1 . This is illustrated graphically in the relative lengths of the time lines of  FIGS. 4   a  and  4   b.    
     Referring now to  FIG. 4   c , there is shown an equivalent time line for the system of the present invention. Here, only approximately six movements of robotic arm  302  are required. While this is faster than the prior art gantry implementation, additional system speed may be achieved because of the independent intelligence contained in the individual counting mechanisms. Because counting may be performed in multiple counting units simultaneously, substantially independently of the movement of robotic arm  302 , additional system throughput may be obtained by optimizing robotic arm  302  travel while simultaneously processing multiple prescriptions. 
     Since other modifications and changes varied to fit particular operating requirements and environments will be apparent to those skilled in the art, the invention is not considered limited to the examples chosen for purposes of disclosure, and covers all changes and modifications which do not constitute departures from the true spirit and scope of this invention. 
     Having thus described the invention, what is desired to be protected by Letters Patent is presented in the subsequently appended claims.