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Description  |
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TECHNICAL FIELD
The invention relates to a materials monitoring system, a materials management system employing information generated by the monitoring system and related methods of managing materials inventories. It further relates to methods for managing or
tracking movements of materials inventory items to or from a storage location, for example inventory stored on one or more shelves in a supplies room or in warehouse bins or racks. In particular, one aspect of the invention provides novel means for
monitoring the movement of product items out of inventory which is especially, though not exclusively beneficial in solving problems occurring in supplying materials to medical suites.
BACKGROUND OF THE INVENTION
A state-of-the-art supermarket is reasonably sophisticated with regard to monitoring of inventory movements and management of inventory. Most items are bar coded to identify them. Customers pick desired items from the shelves, carry them to a
point of sale, such as a checkout counter, where an operator, the checkout clerk, scans each item with a bar code reader to identify and price the item and charge it to the customer.
Scanning its bar code label at the point of sale captures the movement of the item out of inventory and can be used to indicate action to replenish the shelf stock. Drawbacks of this system are that an operator is required to scan individual
items and collect payment, and that inventory movements captured at the point of sale, the cash register may not reflect shelf conditions because some withdrawals from a shelf may not be checked out at the cash register owing to pilferage, breakage,
misplacement and so on. These problems are magnified when efforts are made to apply such inventory monitoring and management practices to materials supplies for medical suites.
In medical suites there is usually no operator to supervise and log the removal of surgical and medical supplies from storage and a medical technician or nurse is expected to track usage and post information on materials used to a patient's
record so that the patient can be billed for them. Needless to say, in the intense, time-sensitive environment of a surgical suite, for example a cardiac suite, where nurses and technicians have other priorities, errors can occur. In some cases
procedures are so loose as to depend upon the use of product labels retrieved from discarded packaging in the suite, after surgery, to log expensive items such as catheters, and even pacemakers, to a patient's record. The probable losses suffered by
hospitals as a result of errors in accurately logging all used items to a patient's record are substantial.
Another problem for hospitals maintaining medical suite supply rooms, is that the stored supplies can represent a of significant capital investment. A single cardiac suite may store half-a-million dollars-worth of surgical supplies.
Consequently, it would be desirable to have vendors carry the cost of such inventory, consignment marketing, while maintaining the inventory on hand at the suite to be available for immediate use. Known inventory management systems that can be operated
in a medical suite lack adequate controls and safeguards for the vendor.
Consignment marketing is a marketing practice wherein a remote vendor maintains an inventory of product items at a customer's facility and invoices the customer facility for each item withdrawn from storage by the customer relieving the customer
of the cost of carrying inventory and of responsibility for reordering. In consignment marketing, the vendor owns the shelf inventory at the customer facility. In re-seller marketing the customer facility buys or becomes responsible for product items
when they are put into storage and subsequently resells the items to end-users or other consumers. In the case of a medical facility, the end users to which products are sold are patients.
Usually, the vendor's representative visits the customer facility at regular intervals, takes inventory, charges the customer for items withdrawn from the vendor's shelf, and replenishes the stock. This system can work well for low cost items in
a relatively well-controlled environment where the primary business is retailing or reselling, but no vendor wishes to entrust thousands of dollars of inventory to a medical facility environment where the inventory controls are poor and reselling
supplies is an activity of only secondary significance to the primary mission of patient care. Discrepancies between total shelf withdrawals and customer's records of relevant billed items may create serious undesirable disputes which no vendor wants to
have with important customers.
There is accordingly a need for a materials monitoring system that can, without requiring operator intervention, track withdrawal of product items from storage in inventory sufficiently well to be useful in a medical suite.
SUMMARY OF THE INVENTION
The invention, as claimed, is intended to provide a remedy. It solves the problem of how to provide an unattended materials monitoring system that can remotely report what items are withdrawn from a storage volume, for example from a storage
shelf. In a preferred embodiment, an electronic shelf unit for storing product items is equipped with an item-sensing grid of sensors which detect the movement of materials product items to and from the shelf and an electronics unit to process sensor
signals and communicate inventory movements remotely.
A remote vendor, or other party can be continually informed of what inventory items are present on the shelf at any point in time, and can use this information to generate bills and reorders. By means of the invention, whenever an item is
removed from the shelf, the shelf unit will automatically communicate to the appropriate vendor, providing time, date, product identification and the location of the shelf.
Preferably, item identification information is posted to the shelf unit and stored there when items are received. Then, when items are withdrawn from the shelf, this information can be accessed, for example by referencing storage locations on
the shelf, and used to identify the items without any further input.
In one broad aspect the invention provides a traffic-sensing electronic product-storage unit comprising:
a) a storage volume for multiple product items;
b) an item activity-sensing subsystem continually to detect numbers of product items in said storage volume and produce a sensed item activity output; and
c) a data-processing subsystem to process said sensed item activity output and report product item traffic including product item withdrawal information;
whereby said product storage unit can automatically generate a product traffic report, including withdrawals of product items from said storage volume, as said withdrawals are made.
Where the product items have individual identification parameters, said data-processing subsystem has parameter sensors to detect one or more of the identification parameters and provide a sensed parameter output, said sensed item activity output
includes product item identification data from said sensed parameter output whereby said product item identification data can be included in said product traffic report.
In another broad aspect, the invention provides an item-sensing product item storage system comprising:
a) a storage volume for storing multiple product items at rest;
b) an item-sensing system to sense the presence of each said product item stored at rest in said storage volume to provide sensor information for generating a first inventory map of said product items stored in said storage volume at a point in
time;
c) a sensor scanner to provide said sensor information for generating a subsequent inventory map of said stored product items at a subsequent point in time; and
d) a data processor to compare said first and previous inventory maps and output a product item movement report of changes in said item inventory.
In a further broad aspect, the invention provides a method of managing a materials inventory maintained in storage at a remote location from a central location physically removed from said remote location, said method comprising:
a) monitoring removal of materials product items from storage by means of a sensor system responsive to displacement of said product items to provide a monitored item report;
b) electronically transmitting said monitored item report to said central location; and
c) using said monitored item report at said central location to initiate replenishment of and accounting for said removed product items.
BRIEF DESCRIPTION OF THE DRAWINGS
Some embodiments of the invention including one way of carrying it out will now be described in detail below with reference to the drawings in which:
FIG. 1 is a schematic representation of a materials monitoring system including several materials storage and traffic-sensing units, each such unit comprising multiple electronic shelf units. The system is locatable at a customer's premises to
provide real-time information on movements of inventory items to a remote location, such as a supplier's facility.
FIG. 2 is an enlarged perspective view of one of the electronic shelf units of the materials monitoring system of FIG. 1, which shelf unit has a hinged front flap, here shown in an open, downwardly disposed position;
FIG. 3 is a view of the electronic shelf unit of FIG. 2, on a reduced scale, with its front flap in an upright, closed position and partially loaded with inventory items;
FIG. 4 is another schematic view of the materials monitoring system shown in FIGS. 1-3, showing means for collecting and relaying inventory data from a multiplicity of item-sensing shelves physically distributed at different locations in a
facility, for example distributed through a supply room or warehouse;
FIG. 5 shows an electronic shelf unit suitable for use in place of the shelf shown of the foregoing embodiments, which shelf unit is provided with access control features;
FIG. 6 is a schematic circuit diagram of a sensing grid for the materials monitoring system of FIGS. 1-5;
FIG. 7 is a schematic circuit diagram of an electronics unit for an electronic shelf unit such as that shown in FIGS. 1-5;
FIG. 8 is a schematic circuit diagram of a shelf supervisory unit for use in the materials monitoring system of FIGS. 1-5;
FIG. 9 is a schematic block flow diagram of an inventory sensing program;
FIG. 10 is a schematic block flow diagram of a column identifier subprogram;
FIG. 11 is a schematic block flow diagram of a comparison test subprogram;
FIG. 12 is a schematic block flow diagram of a row check subprogram;
FIG. 13 is a schematic block flow diagram of a modify column data subprogram;
FIG. 14 is a schematic block flow diagram of matrix update subprogram;
FIG. 15 is a schematic block flow diagram of a horizontal movement subprogram;
FIG. 16 is a schematic block flow diagram of a vertical movement subprogram;
FIG. 17 is a schematic block flow diagram of an item movement subprogram;
FIG. 18 is a schematic block flow diagram of an item add subprogram;
FIG. 19 is a schematic block flow diagram of a pixel add subprogram;
FIG. 20 is a schematic block flow diagram of an item delete subprogram; and
FIG. 21 is a schematic block flow diagram of pixel subtract subprogram.
DETAILED DESCRIPTION OF SOME PREFERRED EMBODIMENTS
The systems and methods of the invention are particularly, but not exclusively, useful to facilitate consignment marketing of materials items, particularly in locations such as medical suites, that are not supervised by a sales or inventory clerk
responsible for checking out product items withdrawn from inventory. It is contemplated that the invention can be beneficial in solving many inventory management problems by removing the point of monitoring of product item withdrawals from a storage
area focal point, such as a centralized checkout or a checkout at a point of egress, as is customary in retail stores, and locating the point of monitoring at the point of storage of each item.
While the invention can be applied to a wide variety of materials items, subject only to their physical suitability for handling by the system of the invention, and their economic significance, a particular field of application is in tracking and
inventory management of medical equipment and supplies, especially surgical equipment and supplies. Such an application will now be described in more detail. A consignment marketing materials monitoring system according to the invention, which is
suitable for a medical suite, is operable at a customer facility to monitor and report materials traffic into and out of storage in storage volumes defined at storage devices at the customer facility. A remote vendor can be equipped with a compatible
materials management system component to receive materials traffic reports, invoice the customer for materials withdrawn from storage and to initiate replenishment of materials stocks at the customer's facility.
The customer facility component of the materials monitoring system of the invention can comprise one or more local materials product storage stations, each of which has at least one traffic-sensing product storage unit, which may be an electronic
shelf unit, as will be described, a facility communicator for remote, long-distance communication of materials product traffic information, and, for facilities with multiple stations, a shelf supervisory unit to relay traffic information to said facility
communicator. Preferably, each traffic-sensing product storage unit, or electronic shelf unit, incorporates its own short-range communicator to transmit unit traffic information to the station or facility communicator and to receive control or product
receipt signals therefrom.
Referring to the drawings, the materials monitoring system shown in FIG. 1 comprises a number of traffic-sensing electronic shelf units 10 for storing materials products. Multiple electronic shelf units 10 can be organized into local product
storage stations 12 which may comprise, for example, racks, bins or bays in a storage or supplies room or warehouse, or may comprise any other convenient grouping of shelf units 10. There is no particular limit to the number of shelf units 10 in a
product storage station 12. Depending on the nature and quantities of the products comprising the stored materials, and upon communications considerations, there are preferably from two to twenty-four shelf units 10 in a storage station 12, and more
preferably from three to eight.
Each electronic shelf unit 10 outputs product traffic information to a shelf supervisory unit 14 which is coupled by communications interface 16 with a vendor's computer 18 supporting a vendor's inventory management system or other software, at a
remote site, via a direct-dial telephone communication or other remote communications link to a vendor's modem 19. Preferably the vendor's inventory management system includes an interface module seamlessly compatible with the customer facility systems
described herein to enhance speed and minimize complexity.
Electronic shelf units 10 sense and can report product usage, or withdrawals, to the vendor, in real time, by sensing the presence or absence of individual product items 30 in storage on the shelf unit 10. Each shelf units 10 can respond to the
withdrawal of a product item stored at rest on the shelf unit 10 by transmitting a product traffic report signal over the airwaves, or via wire, if preferred, to shelf supervisory unit 14, for forwarding via modem to the vendor's computer 18.
A significant and novel feature of the invention is an ability remotely to report product item withdrawals, in real time, without human intervention. By means of the invention, the process of withdrawing an item from the shelf and taking that
item out of inventory for consumption, disposal, onward distribution or other act rendering the host facility accountable to the vendor for that item as a customer for it, can be reliably sensed at the customer's facility, electronically memorialized and
remotely reported. The product-withdrawal reporting system constituted by an electronic shelf unit 10 and its associated communicators is triggered by the physical act of withdrawal of a product item 30. While the act of withdrawal will commonly be
effected by a human materials picker, mechanized inventory retrieval systems can also be employed.
Electronic shelf unit 10 is thus cognizant of product withdrawals and that knowledge can be electronically stored or transported to the vendor where the real-time, or automated on-demand availability of the inventory draw-down information
provided by the system of the invention yields significant business advantages. The materials monitoring system shown can be beneficial within any facility for managing and controlling materials ordering and outward invoicing of items withdrawn. As
such it is particularly beneficial to remote vendors desiring unattended tracking of product withdrawals from storage and is especially useful for consignment marketing of items, as describe above, regardless of the particular marketing or business
arrangements.
The prompt availability of fresh, or contemporaneous, inventory drawdown information at the vendor's facility transmitted from the customer facility materials monitoring component reduces distribution delays and effectively moves the point of
purchase from the vendor's facility to the point of usage at the customer's facility. The system of the invention thus facilitates "just-in-time" materials management wherein inventory on hand is minimized and replenishment arrive just prior to
exhaustion. Neither vendor nor customer has to make significant investments in cash-consuming inventory accumulations which may become dated or obsolete.
Up-to-the-minute product withdrawal information can be used at the vendor's facility to bill the customer, to generate new orders for that customer or compile new orders or shipments, to report sales information and for any other purpose the
vendor may choose. Outages and excesses are readily controlled and special measures may be taken. For example, if critical surgical equipment or supplies are unexpectedly exhausted, replacements may be rushed out to the customer by courier or special
messenger. By automatically invoicing the customer according to product traffic movements reported from the electronic shelf units 10, substantial savings in paperwork can also be obtained.
As an alternative to real-time data reporting, product withdrawal data may be retained at a shelf unit 10 or in the vicinity of a local product storage station 12, in permanent electronic storage, and the vendor system may periodically poll each
or the respective electronic shelf unit 10, or other associated data storage system, via communications interfaces 16 and shelf supervisory units 14, to collect the stored data.
An advantage of the system of particular value to a medical facility or medical suite is that the medical facility (the customer) can make inventory withdrawals of product items, they can be tracked, invoiced by the vendor and replenished without
requiring any paperwork by the medical facility. This is of special value in the pressured atmosphere of a medical emergency, where time is of the essence and may not permit pauses for completion of paperwork to log supplies and equipment used.
The materials monitoring system of the invention described herein enables a vendor to supply merchandise to a customer, especially for example to a hospital, on consignment, with confidence that the customer will be accountable for used product
items. The vendor does not have to send a representative manually to inspect the consigned inventory at the customer's facility to generate an invoice and reorder. Nor must the vendor rely upon the customer's uncertain efforts to those ends. Instead,
the vendor can have all the information needed for efficient materials management, with immediacy and confidence in its accuracy.
In addition to the benefits provided to the vendor, and the customer advantages of reduced paperwork and reliable restocking, pursuant to the invention, as will be further described hereinafter the customer can also use the product usage data
generated by the system of the invention. The product usage data can be incorporated in the customer's systems to ensure that the end user, or in the case of the medical facility, the patient, is held accountable for, or billed for, withdrawn items.
By employing simple expedients, such as a requirement to enter a user identifier before a product can be released from inventory, user allocation of withdrawn product items can be established. Some access control to prevent unidentified
withdrawals is preferable, for example a physical locking system to restrict access to product items, or an audible alert of unidentified withdrawals, or both measures. Utilized in this manner, the materials monitoring system of the invention, with its
traffic-sensing product storage units can tighten the materials dispensing procedures used at many medical facilities giving managers of those facilities confidence that all materials or items withdrawn under the auspices of the materials monitoring
system of the invention will be billed or otherwise accounted for by patients. Subject to the accounting methods employed by the customer facility, consignment marketing using the materials monitoring system of the invention enables the customer
facility to pass through the costs of consigned materials product items and avoid investment in them.
Electronic shelf unit 10
Referring now to FIG. 2, one embodiment of product storage and traffic-sensing electronic shelf unit 10 for use in the materials monitoring system described in FIG. 1 comprises a tray-like shelf 20 having a back panel (not shown), a bottom panel
which is also out of sight, side panels 22 and a fold-down front panel 24 with hinges 26 pivotally securing front panel 24 to the bottom panel.
Electronic shelf 20 defines a storage volume, for receipt of product items 30, between its front, side and back panels, the upper limits of which storage volume are determined either de facto by only permitting storage of a single layer of
product items 30, or by physical constraints, (not shown), such as an overhead cover, or a higher shelf in a rack or bay of shelves.
The inside surface 28 of front panel 24 which is exposed when it is folded down as shown in FIG. 2 provides a convenient location for displaying the vendor's instructions for use of the electronic shelf unit 10. These instructions may include
detailed listing of user-input function codes and the like, if a user input device is also provided (see FIG. 5). Also, vendor-specific product usage instructions and codes required for loading product onto the shelf can be located on the inside of the
front panel.
Electronic shelf 20 is a self-contained, retro-fittable materials storage and monitoring system equipped with item-sensing, data-processing and communications subsystems to enable it automatically to monitor traffic of product items 30 received
by and withdrawn from the storage volume provided by shelf 20 and report that traffic remotely.
An item-detecting subsystem comprises a sensing grid 32, covering the bottom panel of shelf 20 which sensing grid 32 comprises an array of sensors 33 responsive to the presence of product items 33. Sensors 33 are preferably binary and provide a
digital output. However, if a proportional weight-related signal or other graduated signal output is desired, sensors may be analog and the output signal can be converted to digital for processing.
Shelf 20 and grid 32 support product items 30 so that the presence of any product items 30 stored on shelf 20 is detected by sensing grid 32 which is constantly being scanned by a microprocessor in an electronics unit 34. Any activity detected
by the electronics is transmitted to a supervisory unit using infra-red optical signaling, as described in more detail in connection with FIG. 4.
Sensing grid 32 can comprise an array of sensors, for example pressure transducers providing co-ordinates for describing sensed patterns or footprints so that sensing grid 32 is responsive to both weight and form parameters of product items 30.
Additional sensors, or additional such sensing grids, may be incorporated into side panels 22 and back panel of shelf unit 20, depending upon the shape and size of product items 30. In the embodiment shown, product items 30 are depicted as
packaged standardized square-sided box containers for optimal modular space utilization and to provide a simple footprint that can be easily sensed.
Clearly, items 30 can comprise any product that will fit within shelf 20. The system is particularly beneficial for merchandising product items 30 of significant value, for example, items having a value in excess of about $50.00, some examples
of which can be as physically diverse as pacemakers, catheters and other cardiac supplies as well as swabs, forceps, drugs, and so on. Individual items 30 may vary in shape, although they will usually be boxed, and frequently, different products may be
packed in similar boxes, the contents being externally identified.
Preferably the product packaged in or constituted by each item 30 is identified by a product label 31 which is desirably machine-readable. Label 31 can be, for example, a bar-code label, but can take other forms, for example magnetic,
holographic, radio-emitting and so on. The importance of watertight tracking of inventory movements while permitting effortless withdrawal of product items 30 is readily apparent for expensive items.
The system is also beneficial for tracking low cost items, especially commodity items, if they are used in significant volume. Products such as tape and swabs will rarely be subject to individual accounting, leading to shortages when they pass
reorder points without triggering reorders, and possibly underbilling. The relatively modest costs of deploying the materials monitoring system of the invention for such consumables can quickly be amortized by elimination of these inefficiencies.
Other sensors can be used in addition to or in place of the pressure transducers in sensing grid 32. For example optical sensors (not shown) may operate between side walls 22, or between front panel 24 and the rear panel of electronic shelf 20,
to provide information about the extent of product items 30 into a plane above sensing grid 32.
Other types and arrangements of item sensors will be apparent to those skilled in the art.
Depending upon the application, sensors 33 may be optical, piezoelectric or capacitative, or may employ any other physical principle permitting detection of movement of a product item 30 out of an at-rest storage position on shelf unit 20.
Optical sensors each comprising a light emitter and a detector unit can be used. Such light emitters may be small incandescent units, or emitter cells but are preferably laser diodes, the detectors being chosen according to the nature of the emitter.
Incoherent light or incandescent sources are undesirable for battery-powered shelf unit applications, in view of their power requirements.
An alternative sensor 33 is a piezoelectric sensor which has the advantage of being signal-generating and therefore not requiring a power supply. Another alternative is a capacitive sensor the capacitance of which changes in response to pressure
from the weight of product items 30.
A precise orthogonal grid arrangement of sensors 33 may induce moire-like effects in the electronic output, confusing interpretation of the signal, analogously to moires that can occur in dot-based process printing and are avoided by adjustment
of the dot angle of one or more of the primary inks. Although moire interference may be eliminated by electronic filtering it is preferred to avoid, or reduce the interference by suitable relative positioning of sensors 33.
To this end, a preferred sensor arrangement employs a somewhat irregular spatial distribution of sensors, for example, an at least partially randomized distribution whereby, on one, larger granularity scale, the spatial distribution of sensors is
relatively uniform, within specified brackets of variation, whereas on a smaller granularity scale, the distribution of sensors 33 displays a significant degree of randomness. Thus the distribution may be such that a product item 30 occludes a
relatively constant number of sensors 33 as it is moved about sensing grid 32, yet at a granularity comparable with an average spacing between sensors, the distribution displays significant randomness.
Alternatively, an offset arrangement may be used whereby each sensor 33 is disposed at a fixed distance from a regular grid point which distance is small compared with the grid pitch, for example from one-tenth to one quarter of the grid pitch,
the directions of offset of neighboring sensors being correlated so that pairs of neighbors are offset in different directions and preferably are balanced about their respective grid points.
In an embodiment suited to mass production of sensing grid 32, sensors 33 are solid-state semiconductor devices and sensing grid 32 is produced in continuous film manner employing for example a polyester film such as MYLAR film (trademark DuPont)
as a substrate to support the sensor array and related circuitry and wiring which can be fabricated by techniques such as chemical vapor deposition or other techniques known to the semiconductor fabrication arts. Using a pressure-responsive, e.g.
compressible, dielectric material, sensors 33 can be capacitive. Arrays of capacitative devices draw very little current.
Described has been an item sensing system which is essentially operative in the plane of item-supporting shelf 20 on which product items 30 rest during storage, which may optionally be supplemented by one or more complementary sensors in a plane
or planes above the item support surface. This is one way of sensing the presence of items in the item storage volume defined above shelf 20. Other sensing systems can be used, for example three-dimensional movement detection systems employing
infrared, ultrasound, optical, radiowave or other signalling techniques, accompanied by suitable processing such as ranging or imaging to determine the inventory status of stored items 30 on electronic shelf unit 10 and, more specifically to determine
what items 30 are stored at what locations on shelf 20 at any given moment.
Electronics unit 34
In addition to the product storage and sensing functions provided by shelf 20 and sensing grid 32, electronic shelf unit 10 is equipped with a built-in electronics unit 34 providing electronic services including interpretation of signals from
sensing grid 32 and storage and communication of descriptive and quantitative informati | | |
