WO1994027516A1

WO1994027516A1 - Expendable instrument accountancy apparatus

Info

Publication number: WO1994027516A1
Application number: PCT/US1994/006108
Authority: WO
Inventors: Henry H. Fletcher; William B. Morse; Robert E. Budris; Michael G. Fisher; Richard G. Hamilton; Keith L. Mullowney
Original assignee: Synvasive Technology, Inc.
Priority date: 1993-06-01
Filing date: 1994-06-01
Publication date: 1994-12-08
Also published as: AU7097194A

Abstract

A system for assessing the use of a monitored unit, such as a medical implement or surgical instrument. The system includes as its primary components a station and the monitored unit. The station is optionally coupled to an accounting computer as well as to a printer. The station includes a multi-processing unit (MPU) which receives information from a memory and directs and receives information to and from a system interface. The system interface also communicates with a user interface, and can output information to a display. The system interface is also capable of interfacing with the monitored unit and more particularly with an identification (ID) circuit contained in the monitored unit.

Description

EXPENDABLE INSTRUMENT ACCOUNTANCY APPARATUS

BACKGROUND OF THE INVENTION

The present invention relates to an apparatus and method for monitoring and accounting for the use of instruments, or semi-durable goods, and more particularly to a system for accounting for the use of expendable or reusable instruments or semi-durable goods, and for generating a report based on the use. The report may be in the form of a billing statement or rental statement, or a history of the monitored unit.

In certain fields, particularly in the field of medical instruments and surgical instruments, it is common for a manufacturer to attempt to make a durable good which has an extended life, and is therefore fabricated from expensive materials, which is sold to an institutional user. For instance, in the medical or surgical instrument field, an example would be a bone saw or more generically a motor drive unit for various types of surgical instruments. For these devices, it is common that the expected life of the product may be three to five years while the warranty may last only for the first year. A manufacturer may derive a significant income based upon non- warranty repairs during the product life.

The foregoing described approach, while profitable for the manufacturer both in the original sale of the instrument and subsequent repairs, is not particularly attractive to the institutional user. In addition, some potential users can not justify the initial purchase price or the subsequent repair costs for the instrument. It would therefore be beneficial to have an instrument that can be provided to the user by the manufacturer on an alternative accounting arrangement.

While the concept of the present invention is generally applicable to a wide range of potential applications, an apparatus and method of carrying out the invention for select examples will be discussed and addressed below for purposes of detailing the invention. In this regard, certain prior art is particularly relevant to the types of devices which are best suited to adaptation of the contemplated apparatus and method. While the following discussion is intended to establish the background of the present invention, it is to be appreciated that once the invention has been defined, it will be readily apparent to those skilled in various art fields that the inventive concept can be applied to a number of areas and alternative devices. Specifically, with respect to electric motor-driven devices, for example surgical instruments, it would be very beneficial to be able to determine the actual use of the device for a particular operation or patient, and to generate a report of the usage, such as for example an invoice for the services, either to or for the user. Thus, the operator would require the ability to monitor a use parameter for the device and generate an output signal based on the monitored use parameter.

As a specific example, portable battery-powered motor- driven devices such as those used for hand saws and drills in the surgical field have a battery charged to capacity prior to their use. Once used, the battery pack is at least partially discharged. Various patents discuss specific methods of determining optimum methods of recharging batteries after use. For example, several patents to Steven E. Koenck assigned to Norand Corporation address in detail battery charging systems.

These patents include U.S. Patent No. 4,553,081 ; 4,709,202; 4,737,702; 4,885,523 and 4,961,043. The foregoing patents apparently do not discuss a method of determining exactly how much use was obtained from the battery between charge cycles.

Accordingly, for a battery-powered instrument, it would be very beneficial to have a method of determining the amount of battery charge used during a particular operation, such as a surgical operation for a medical instrument, and based upon the battery usage, generate a report or invoice for the use of the instrument.

SUMMARY OF THE INVENTION

Fundamental to the present invention is the concept of monitoring a physical or tangible aspect associated with an expendable or reusable device or instrument, and generating a report such as an invoice for the use of the device or instrument. The preferred embodiment, used in conjunction with a rechargeable battery-powered motor-driven surgical instrument, contemplates having a method and apparatus for determining the amount of battery charge used during a particular procedure. The battery charge use is determined by first recording the initial charge of the battery, and then determining the charge remaining in the battery after its use. Based upon the charge utilized during the procedure, a report is generated for invoicing the use of the particular instrument. Thus, for a system which monitors the usage of a surgical drill or saw (for example) the amount of charge used by the particular type of drill or saw would be cross referenced to a table stored in an electronic memory to generate a report or invoice fixing a pro-rated cost or fee for the use of the surgical drill or saw.

Additional aspects of the invention contemplate having an identification system, such as an electronic identification circuit having a code which is determinable by the battery charging station, on each particular device or instrument, such as the surgical instrument or motor-driven saw or drill. Thus, rechargeable battery-powered motor-driven surgical instruments may have a built-in identification circuit having a unique code identifier. The identification circuit can be accessed via electrical contacts, or remotely accessed utilizing a radio frequency system, upon the return of the instrument to the battery charging station. The battery charging station, or more generally an instrument control center, would include a system for reading the information from the identification circuit and would also include a data storage memory to store data concerning the particular type of instrument associated with an identification code.

The data storage memory may also retain specific data relating to the use and past history of the particular instrument.

This information is used to determine, for example, when the particular instrument should be taken out of service, when a physical element within the instrument may be subject to an unacceptable failure rate, or when the particular instrument has been mishandled with respect to a required procedure. For example, surgical instruments must be sterilized, and in certain cases autoclaved, prior to their use for a surgical procedure in order to prevent the possibility of infecting the patient. The autoclaving procedure or sterilization procedure may be monitored, or the identification circuit of the instrument may be responsive to the occurrence of these types of procedures, causing the identification circuit to record and communicate the occurrence of the sterilization or autoclaving process to the instrument control center upon its return. Further, as such procedures can often affect the useful life of surgical instruments, the instrument control center is preferably capable of tracking the number of occurrences of the sterilization and autoclaving procedures.

The instrument control center is also capable of recording the current usage and the amount of use of an instrument which it is programmed to monitor. The system is capable of generating a report based on the use, which can be credited or invoiced to a particular account. The system may also include a means for entering data concerning the particular use. For example, within the surgical instrument field, the patient identification number, doctor, procedure, and other information can be entered into the system to coordinate the billing procedure.

The system is particularly useful to a manufacturer who provides a semi-durable instrument to a user in a manner promoting an accounting for the individualized use of the instrument. Thus, a surgical saw or motorized drill could be fabricated as a semi-durable good, and in essence rented to the user based upon actual usage of the device. The system self-monitors actual usage, generates a bill for the user to invoice a particular account or client, and also invoices the user for a pro-rated portion of the use based cost to be remitted to the manufacturer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of the system of the present invention;

FIG. 2 is a perspective view of an embodiment of the system of the present invention schematically diagrammed in FIG. 1 ;

FIG. 3 is a wiring diagram for a motor-driven instrument including an identification circuit;

FIGS. 4 and 5 are wiring diagrams for the interconnection circuitry to read the identification circuit; FIG. 6 is a schematic representation of the major components of the station depicted in the system of FIGS. 1 and 2;

FIG. 7 is a detailed schematic representation of the major components of the station of FIG. 6; and FIG. 8 is a flow diagram of the system control logic.

DETAILED DESCRIPTION OF THE INVENTION

The present invention details a system 20 for assessing the use of a monitored unit 24, such as a medical implement or surgical instrument. FIG. 1 is a block diagram of the system 20 according to the present invention. The system 20 includes as its primary components a station 22 and the monitored unit 24. The station 22 is optionally coupled to an accounting computer 26 as well as to a printer 28. The accounting computer 26 and the printer 28 may be physical assets which are in a location, such as a hospital, into which the station 22 is installed and then interconnected.

The station 22 includes a multi-processing unit (MPU) 30 which receives information from a memory 32 and directs and receives information to and from a system interface 34. The station 22 thus has built-in data processing and computing capability wherein look-up tables and instrument use history is retained. The system interface 34 also communicates with a user interface 36, and can output information to a display 38. The system interface 34 is also capable of interfacing with the monitored unit 24 and more particularly with an identification (ID) circuit 40 contained in the monitored unit 24.

The station 22 also includes preferably includes a battery charging circuit 42. The battery charging circuit 42 is interconnected to share information with the MPU 30, and connects to an output power line 44 to be interconnect to a battery in the monitored unit 24. Preferably, the battery charging circuit 42 is capable of providing intelligent charging of the batteries, and can determine the amount of discharge. Thus, the battery charging circuits disclosed, for example, in one of the U.S. Patent Nos. 4,553,081 ; 4,709,202; 4,737,702; 4,885,523 and 4,961,043 are contemplated for the charging circuit 42 of the present invention, while a number of other standard charger designs could be used as alternatives. FIG. 2 depicts a schematic view of an exemplary system

20 according to the present invention. The system 20 includes the station 22 which, as depicted, includes a housing 50 the top surface of which includes a number of recessed areas 52. The recessed areas 52 may include contacts 54 for providing electrical power to charge batteries in the monitored unit 24.

The monitored unit 24 is depicted as being a surgical saw 60. The surgical saw 60 has a pistol grip type housing 62, and a blade 64 which is removable from the pistol grip housing 62. A base 68, of the pistol grip housing 62 is shaped to be inserted into the recessed areas 52 in the housing 50. The housing 50 and more particularly the recessed areas 52 which receive the base 68 of the surgical saw 60 also include an electrical contact 56 which electrically connects to a contact 66 on the surface of the housing 62 of the surgical saw 60. The wiring for the electrical contacts 56, 66 of both the housing 50 and the surgical instrument 60, respectively, are detailed and discussed below.

The station 22 depicted in FIG. 2 also includes the user interface 36 which in this example may be an attached keypad 70. Alternatively, the user interface 36 could be an integral keyboard or keypad, numerical entry keys, a bar code scanning system, or a voice activated control system, all of which are currently available.

In addition, the housing 60 of the station 22 includes a display 38, which is shown as an LCD display 74 on one of the facing surfaces of the housing 50. The housing 50 may also include a power indication light 76 as well as an on/off switch 78. While the display 38 depicted on the housing 50 in the embodiment detailed in FIG. 2 is illustrated as being an LCD display, it may optionally be simply a series of lights 72 on the upper surface of the housing 50 indicating whether a particular instrument which is inserted into one of the recessed areas 52 is being charged or is fully charged, and/or whether or not the instrument is identified by an identification circuit. Further, equivalent methods and apparatus for providing information display, such as for example an attached monitor or flat screen display, will be apparent to those skilled in the art.

While in the embodiment depicted in FIG. 2 the monitored unit 24 is illustrated as being an oscillating saw, the station 22 as well as the monitored unit 24 can be designed to accommodate a number of different types of monitored units 24, such as for example a drill, reamer, or reciprocating saw, as well as the oscillating saw depicted in FIG. 2. For each of these types of devices, all of which may have a pistol grip type of assembly, preferably the bases have a design which fits within the recessed areas 52 on the top of the housing 50 of station 22. The recessed areas 52 can have different shapes, designed to accommodate at least one of the alternative devices. However, it would be beneficial to have the shape of the bottom portion or base 68 of the monitored units 24 uniform, so that any particular unit could fit into any one of the recessed areas 52.

Alternatively, the monitored unit 24 may be an electrical surgical instrument such as an arthroscopic shaver 46 interconnected to the station 22 via a cable 48. The station 22 can be used to monitor the use of a detachable cutting device 49 which is outfitted with an identification circuit and electronic code such as the ID circuit 40 discussed in detail below. The cutting device 49 is attached to the distal end of the shaver 46, which provides a feed through electrical circuit for allowing the station to interrogate and instruct the ID circuit 40 on the detachable cutting device 49. In this configuration, the station 22 can monitor the use of attachments to shaver 46, such as the cutting device 49, to determine wear and help prevent catastrophic failure of the attachment during use.

Additionally, monitoring the shaver 46 and cutting device 49 via interrogation of the ID circuit 40 therein can supply data to the station 22 that can be displayed to the user, and the use of the device can be recorded for invoicing. For example, the total elapsed time of usage of the cutting device 49 may be recorded to the ID circuit 40, and displayed on the station 22. By periodically recording the amount of use of the cutting device 49 to its ID circuit 40, and displayed on the station 22. By periodically recording the amount of use of the cutting device 49 to its ID circuit 40, the usage data can remain with the cutting device 49 after it is detached from the shaver 46 for a subsequent operation.

FIG. 3 is a schematic depiction of the basic circuitry for the monitored unit 24 such as for example the oscillating saw 60 of FIG. 2. It should be understood that the basic components depicted in FIG. 3 are equally applicable to the other types of devices, such as a drill, reamer, or reciprocating saw. Each of these instruments may include a motor 80, a battery pack 82, an on/off switch or a control switch 84. In addition, a second battery pack 86 may be included to provide additional power and/or backup power, and also simply for purposes of balancing the weight distribution within the monitored unit 24 so that it is comfortable in the hand of the user. The circuit in FIG. 3 also depicts the ID circuit 40 as having three electrical terminals 92, 94 and 96. Only two of the terminals are used in the embodiment depicted in FIG. 3. The first terminal 92 of the ID circuit 40 is connected to the ground side of motor 80. The second terminal 94 of the ID circuit 40 is connected via interface lead 98 to the contact 66, which as described above is physically located on the outer surface of the monitored unit 24 (as shown in FIG. 2) such that the contact 66 can electrically connect to the contact 56 within the recessed area 52 of the station 22. For the ID circuit 40 depicted in FIG. 3, it is not necessary that the ID circuit 40 obtain power from the battery packs within the monitored unit 24. However, for other types of ID circuits, it is contemplated that an ID circuit may require power, such as for example that shown by the dashed line from the third terminal 96, on the ID circuit 40, which interconnects to the powered side of at least one of the battery packs 82. Generally, it is preferred that the ID circuit 40 of FIG. 3 obtains power while being interrogated by the station 22, when the monitored unit 24 is inserted into the station 22. A preferred embodiment of the ID circuit 40 is the model:

"DS2400 Silicon Serial Number," produced by DALLAS SEMICONDUCTOR. This device contains an 8 bit model number, a unique 48 bit serial number, and an 8 bit cyclic redundancy check value embedded in a silicon housing. All signaling necessary for reading or writing to the DS2400 is provided to the second terminal 94 via the interface lead 98. The silicon housing of the DS2400 provides a small, low cost enclosure. Power for reading and writing is derived from the interface lead 98, with no need for a separate lead to an external power source. Thus, the ID circuit 40 provides a unique serial number for identifying each particular monitored unit 24 into which one of the ID circuits 40 is implemented.

Alternatively, an enhanced ID circuit 40 may include the model "DS2223 (or DS2224) ECONORAM" manufactured by DALLAS SEMICONDUCTOR. These ECONORAM's are fully static, micropowered, read/write memories packaged in low cost silicon packaging. The DS2223 is organized as a serial 256 times 1 bit static read/write memory. The DS2224's first 32 bits are lasered in with a unique ID code at the time of manufacture, with the remaining 224 bits available for static read/write memory. The interrogation signaling necessary for reading or writing is accomplished via the interface lead 98 in these enhanced embodiments, as in the basic configuration using the DS2400. For the enhanced versions of the ID circuit 40, in addition to having a unique identification code for each monitored unit 24, the type of device and model number of a particular monitored unit 24 can be written to, and stored within, the ID circuit 40. This information is thereafter available for interrogation by the station 22. In this enhanced embodiment, the ID circuit 40 will be capable of identifying, for example, that the particular monitored unit 24 is a surgical saw (60 in FIG. 2), having a specific model number. This information, once read by the station 22, can be used to instruct the MPU 30 of station 22 on various parameters, including proper charging requirements for the monitored unit 24 as well as proper billing formats and cross-indexing of the report generation function.

The circuitry included within the station 22, and more specifically within the system interface 34, which is intended to interact with the ID circuit 40 is partially depicted in the wiring diagrams of FIGS. 4 and 5. In FIG. 4, the basic components for the system interface 34 of the station 22 are depicted. The system interface 34 includes transmit and receive circuitry 102, which sends a signal through a transmit buffer 104 via signal line 106 to the monitored unit 24, and more specifically the ID circuit 40 thereof. The ID circuit 40 produces an ID signal which returns on signal line 106 to the system interface 34. The system interface 34 directs the returning ID signal through a receive buffer 108, and then to the transmit and receive circuitry 102.

The system interface is interconnected to ground within the station 22, as shown by ground 110. In addition, the ID circuitry 40 is connected to a ground 112 within the monitored unit 24. When the monitored unit is inserted into the station 22, the common or ground 110 for the recharge system is tied to ground 112 in the station 22 and monitored unit 24, so that the system can reference a common ground during signal processing. In addition, an optional power line 116 may be provided from the station 22 to power the ID circuit 40.

The details of an exemplary embodiment of the circuitry of the system interface 34 are more specifically depicted in FIG. 5 as including a first pair of invertors 130, 134 which are interconnected in a cascade arrangement having outputs which are tied to a five volt system power supply (VOC) through pull up resistors 132, 136, respectively. With VOC equal to 5 volts, the resistors 132, 136 are preferably 4.7ΛΩ. The output of invertor 134 is also connected with a zener diode 140 which is tied to ground through resister 138. The zener diode 140 in combination with the resistor 138 provides for protection for the invertor 134, while the resistor 138 limits the current through the zener diode 140. A second cascade arrangement of invertors 144, 148 is provided to receive the ID from the ID circuit 40 located in the monitored unit 24. As with invertors 130, 134, the outputs of invertors 144 and 148 are tied to VOC through resistors 146, 150 which are also preferably 4.7κΩ. A resistor 142 provides voltage regulation on the data line interconnecting the system interface 34 with the ID circuit 40. The cascade arrangement of invertors 130, 134 and 144, 148 regulates the levels of the inputs to, and outputs from, the ID circuit 40.

As the ID circuit 40 will be different (i.e. physically it will be a different circuit) in each monitored unit 24, each circuit could have varying voltage levels signifying high and low. For example, in one monitored unit 24 a high may be five volts and a low may be zero volts. In another monitored unit, a high may be 4.7 volts while a low may be .4 volts. The cascade arrangement of the invertors, coupled with the tying of the outputs of the invertors to VOC through the resistors such as 132, 136 and 146, 150, allows the system interface 34 to regulate the highs and lows so that the output of the invertor 148 will provide constant values for highs and lows. In this fashion, the MPU, which is shown in more detail in FIGS. 6 and 7, will receive constant values indicative of highs and lows from the system interface 34.

A "read" request from the MPU 30 is passed through invertors 130, 134, to contact 66 through resistor 142. In response to the read request, the ID circuit 40 supplies a serial output through resistor 142 and invertors 144, 148 indicative of its identification number. The identification number is output from invertor 148 and supplied to the MPU 30 as a serial data stream.

In the general circuit diagram of FIG. 6 and the more specific circuit diagram of FIG. 7, the components of the station 22 are depicted. In FIG. 6, the station 22 and the monitored unit 24 are illustrated. The station 22 includes the microprocessor 30, system read only memory (ROM) 118, system random access memory (RAM) 120, host interface 122, and printer interface 124 all interconnected as shown by address and control bus 126 and data bus 128. Each of these components may also be interconnected to the keypad 70, display 38 and system interface 34 via the address and control bus 126 and data bus 128.

In FIG. 7, MPU 30 is depicted as including a microprocessor 152, such as an INTEL 8051 or 8052, which is coupled to memory circuits 154, 156, 158 and 160 via the address BUS 126, control lines 127 and data bus 128. It should be understood that while the disclosed embodiment incorporates four memory storage devices, the present invention is not limited to a specific number of memory storage devices. The memory circuits 154, 156, 158 and 160 are typically random access memory chips (RAM) but may also be a combination of RAM and read only memory (ROM) chips. The memory circuits 154, 156, 158 and 160 store the program code and data which are utilized by the microprocessor 152 to determine the amount of use of the monitored unit 24, the type of use (e.g. surgical procedure, sterilization, autoclaving, etc.), as well as the specific type of monitored unit 24 (e.g. from the identification number received from the ID circuit 40). Also shown in FIG. 7 are various subcircuits which are interconnected to the microprocessor 152 through the address bus 126, control lines 127 and data bus 128. The subcircuits include a reset circuit 162 which is used to provide a reset signal via line 163, for resetting the microprocessor 152. The reset circuit 162 includes a switch 164, coupled to a resistor

165 which is tied to VOC, an invertor 166 and a capacitor 167. The output of invertor 166 is supplied to a circuit 168, which includes another invertor 170 the output of which is the reset signal supplied to the microprocessor 152 by line 163. A clock or timing circuit 172 is provided for use by the

MPU 30. The timing circuit includes an arrangement of a crystal oscillator 178 coupled with capacitors 174, 176. One terminal of the crystal oscillator 178 is coupled via line 175 to a first side of capacitor 174 as well as to a terminal of microprocessor 152. The second terminal of crystal oscillator 178 is coupled via line 177 to a first side of capacitor 176 as well as to a terminal of microprocessor 152. The second terminal for each of the capacitors 174, 176 is connected to system ground. The frequency of the oscillator 178 is preferably 10 MHz, however the frequency may be changed to any frequency which is compatible with the microprocessor 152.

A memory chip size select circuit 180 is also provided for use by the MPU 30 for setting the size of the memory chips used for memory circuits 154 - 160. The size select circuit 180 is interconnected to the address bus 126, and thereby to the microprocessor 152 and memory circuits 154 - 160. The size select circuit 180 has a terminal connected to VOC, as well as terminal connected via line 181 to a terminal of memory circuits 156 and 158. The size select circuit 180 can short appropriate pins with jumpers to select memory sizes ranging, for example, from 64 kilobytes to 256 kilobytes. Other memory sizes are, of course, within the scope of this invention.

An output header circuit 182 is interconnected to the address bus 126 and the data bus 128, and thereby to the microprocessor 152 and memory circuits 154 - 160. The output header circuit 182 is also connected to a pair of terminals on each of the microprocessor 152 and memory circuits 154 - 160 via lines 183 and 184. The output header circuit 182 is also connected to VOC, as well as to system ground. The output header circuit 182 assists in the control of the output connections between the MPU 30 and the accounting computer 26, the program memory 32 and the system interface 34. A programmable array logic (PAL) chip 186 is provided for implementing memory select logic for selecting the appropriate memory circuit 154, 156, 158, 160 depending on selected bits of the memory address. PAL chip 186 is connected via the address bus 126 to the microprocessor 152 as well as the memory circuits 154 - 160. Input terminals of the PAL chip 186 are connected to output terminals on the microprocessor 152 via lines 187, 188. Three output terminals of the PAL chip 186 are connected to three input terminals on the output header circuit 182 via bus 189. In addition, a pair of output terminals of the PAL chip 186 are connected via ϋnes

190, 191 to an input terminal on the memory circuits 154 and 156, 158, respectively.

The final circuit components illustrated in FIG. 7 are pull- up resistors 192 and 194. The pull-up resistors 192 and 194 interconnect VOC to a pair of terminals on the microprocessor

152 via lines 193 and 195, respectively.

In operation, when a monitored unit 24 is removed from station 22, the MPU 30 in station 22 maintains a record in memory circuits 154 - 150 of the current state of monitored unit 24. Such information may include, for example, the state of charge of the batteries in the monitored unit 24. The monitored unit 24 is removed from the station 22 and utilized, for example, in a surgical procedure, and is replaced into a recessed area 52 in the station 22 upon completion of the procedure. The station 22 then communicates with the monitored unit through contacts 56, 66 which are formed on the station 22 and the monitored unit 24, respectively. The MPU determines the identity of the monitored unit 24 from the information supplied by the ID circuit 40 through the system interface 34, and also preferably determines the amount and/or condition of use of the monitored unit 24.

For example, the station 22 calculates the remaining battery life in the monitored unit 24. From the remaining battery life, the station 22 determines the amount of usage of the monitored unit 24 by referencing the stored state of the batteries when the monitored unit 24 was removed from the station 22. At this point, the MPU 30 can calculate an amount of use of the monitored unit 24, and supply this information to the accounting computer 26, which can then calculate and generate an appropriate invoice for the amount-of-use, or generate a report based upon the results of the amount-of-use calculation. In addition to supplying this information to the accounting computer 26, certain information can also be displayed on the LCD display 74 in the station 22 or, alternatively, may be displayed utilizing the LED's 72.

In addition to providing an accounting of the amount of use of the monitored unit 24, which can be utilized to generate a bill for a patient or for an institution, the information regarding the usage of monitored unit 24 can also assist a user of the monitored unit 24 in determining whether it is necessary to recharge the monitored unit 24 prior to using the device again. The display of the usage information on the display 74 provides an immediate feedback to the user regarding the current capabilities of the monitored unit 24. If recharging of the monitored unit 24 is necessary, this can be done directly in the station 22 through the contacts 54 located at the base of the recessed areas 52 which match up with corresponding contacts (not shown) in the base 68 of the monitored unit 24. The system 20 can generate a broad range of reports based upon the usage of the monitored unit 24. Many surgical instruments have a limited useful life which depends on the amount of use thereof. For example, a battery-powered oscillating saw may only be suitable for use for one hundred hours of battery time, after which the device must be replaced. Accordingly, it is possible with the present invention to generate a report which may be used for billing purposes based upon the percentage of use of the useful life of the instrument as tracked by the station 22. Thus, it may be possible to amortize the cost of the instrument over a number of patients based on each patient's percentage of use of the useful life of the instrument.

As mentioned previously, the station 22 can monitor the type of use of the instrument. Thus, when the monitored unit includes an advanced identification circuit which is capable of being written into, it is possible for the station 22 to determine when the monitored unit 24 has been subjected to an autoclaving or sterilization procedure. The autoclaving and sterilization procedures can often contribute to the shortening of the useful life of the instrument due to the extremes to which the instrument is subjected during such procedures.

Accordingly, as with the amortization of the useful life of the instrument based upon the use thereof as discussed above, the impact upon the useful life of the instrument when it is subjected to such procedure can also be amortized over the life of the instrument with the patients or institutions being in charge accordingly based upon the report produced by the accounting computer 26.

FIG. 8 shows a basic system flow diagram for the operation of the system 20. At step 200, the system operation is started. This typically includes the power up sequence for the station 22 which may involve resetting of counters and registers by the MPU, a memory check routine, and routine system diagnostics, etc. In addition, the operator of the station 22 may, at this point, input patient information into the system 20. At step 202, the station 22 attempts to read the ID for the monitored unit 24. The read step may be initiated through a timing circuit, direct input from the operator of the station 22, or the read may automatically be initiated when the monitored unit 24 is placed in the station 22. The communications with the monitored unit includes execution or transmission of the interrogation protocol for a particular ID circuit. An example of an exemplary interrogation circuit and method is disclosed in U.S. Patent No. Re. 34,241, dated May 4, 1993, herein incorporated by reference. At block 204, a determination is made as to whether the monitored unit 24 is placed in the base station 22. This decision may be made based upon whether there is a response to an interrogation attempt in step 202. If it is determined that the monitored unit 24 is not in the base station 22, the system can proceed to step 206 where various keyboard commands are processed. In step 206, the user of the system may, at this point, enter doctor or procedure data into the system which would then be useful in writing to a monitored unit 24, or in determining which monitored unit 24 should be placed into the base station 22. In addition, printouts may be generated at this point to use as confirmation of the data which has been entered into the base station 22 by the user.

The results of the keyboard commands entered in step 206 may be displayed and, at the same time, a printout may be generated in steps 210, 212. In addition to printing out the data which has been entered by the user in step 206, the patient's chart or file history may also be printed out or updated. If the appropriate patient or procedure data is not present in the system 20, it may be necessary for the system

20 to interact with a host or remote system to obtain the information necessary for the proper monitoring of the device 24 or to obtain information on a particular patient. If access to a remote system is required, in steps 214 and 216 the system will determine that modem communication with a remote system are needed and will exchange data with the host (i.e. remote) computer. Another factor which may result in the need for communicating with the host system is the generation of billing reports and the obtaining of billing data which may be maintained in an accounting computer system which is located remote from the system 20.

The system 20 proceeds to determine whether it is necessary to update the memory in the station 22. For example, if data has been obtained from a remote source or if it was determined in step 204 that the device was in the base station 22 and the system has proceeded through steps 224- 234 (which will be discussed in more detail below), it may be appropriate to update the station memory. If the station memory is to be updated, the system proceeds to step 222 where the base station 22 memory is updated with such information as usage data for the monitored unit 24, patient information, etc. At this point, the system returns to step 202 and proceeds as discussed above.

If a determination is made in step 204 that the monitored unit 24 is present in the base station 22, the system proceeds to read the identification code and stored information in the device ID circuit 40 in step 224. In step 226, a determination is made as to whether the ID of the monitored unit 24 has already been read. This may be done by comparing the ID read from the monitored device 24 to stored data representative of other identifications which have been previously read. If a match is found, it is determined that the ID of the monitored unit 24 has already been read. The specifics of the unit, for example, model no., the charge level prior to use, the number of prior uses, etc. are then recalled. The system then proceeds to step

206 and proceeds as discussed above.

If the ID of the monitored unit 24 has not been read previously, the system proceeds to step 228 where information about the monitored unit 24 is determined and stored in the memory associated with MPU 30. Such information includes the battery charge state, the number of prior uses of the device, the number of sterilization cycles which have been completed, the number of autoclaving cycles which have been completed, etc. If the unit was placed into the base station 22 for charging, step 228 may need to be done periodically until the unit is fully charged. In step 230, the information obtained in step 228 is then processed. It is determined in step 232 whether it is necessary to update the information stored in the monitored unit 24. For example, it may be necessary in step 234 to increase the count of a counter maintained in the device as to the number of uses thereof, etc. At this point, the system then proceeds to step 206 to process the commands which have been entered by the user of the base station 22. In this fashion, the information which has been obtained from steps 226 - 228 may be used to generate billing reports, or reports on the state of use of equipment, whether it is necessary to replace the equipment which is being used, etc.

The above discussion of the basic flow diagram shown in FIG. 8 is one possible example of the operation of the system of the present invention. It is to be understood that the present invention is not limited to operation in accordance with the flow diagram shown in FIG. 8, and that one skilled in the art would readily understand how to modify the disclosed flow diagram to obtain equivalent results without departing from the spirit and scope of the present invention.

It should be evident that the foregoing description of the present invention provides many advantages over existing procedures used for monitoring instruments. Although preferred embodiments are specifically illustrated and described, it will be appreciated that many modifications and variations of the present invention are possible in light of the above teaching. Accordingly, the foregoing embodiments are merely for illustration purposes and the scope of the present invention is limited solely by the proper literal and equivalent scope of the claims which are appended below.

Claims

CLAIMS What is claimed is:

1. A system for assessing the use of a portable monitored unit, comprising: an identification circuit included within said monitored unit; a station including data processing computing capability, said station also including: means for receiving at least a portion of said monitored unit; and means for interrogating said identification circuit in said monitored unit.

2. The system of Claim 1 wherein said station further includes: means for generating data for a report based upon the results of said interrogation of said identification circuit.

3. The system of Claim 1 wherein said station further comprises: means for communicating with a remote computer system, and for reporting the results of said interrogation of said identification circuit to the remote computer.

4. The system of Claim 1 wherein said station further comprises: means for interfacing with an operator of said system and for receiving data information.

5. The system of Claim 1 wherein said station further comprises: means for displaying information about said monitored unit.

6. The system of Claim 1 wherein said means for receiving comprises: at least one receiving depression, said receiving depression including electrical circuitry for interacting with said identification circuit.

7. The system of Claim 6 further comprising: rechargeable battery means in said monitored unit for providing electrical power; and charger means for charging said rechargeable battery means, said charger means contained in said station.

8. The system of Claim 7 wherein said station further comprises means for determining the duration of use of said rechargeable battery of said monitored unit.

9. The system of Claim 1 further comprising: circuitry means for monitoring a physical parameter indicative of the use of said monitored unit and for generating data; and means for retaining the monitored data.

10. The system of Claim 9 wherein said means for interrogating further comprises: means for extracting said monitored data from said means for retaining.

11. The system of Claim 9 further comprising: means for retaining a use history of a plurality of said monitored units.

12. The system of Claim 9 further comprising: means for invoicing based upon the use of said monitored unit.

13. The system of Claim 9 further comprising: means for correlating a use of said monitored unit with a data parameter entered via said user interface; and means for generating a report of the correlated use and said entered data parameter.

14. The system of Claim 9 further comprising: means for determining whether said monitored unit has been used during a period of time during which said monitored unit was separated from said station.

15. A system for assessing the use of a portable unit, comprising: an identification circuit included within said portable unit; a station including data processing computing capability, said station also including: means for receiving at least a portion of said portable unit; means for interrogating said identification circuit in said portable unit; means for generating a report based upon the results of said interrogation of said identification circuit; means for communicating with a remote computer system, and for reporting the results of said interrogation of said identification circuit to the remote computer; means for interfacing with an operator of said system and for receiving data information; and means for displaying information about said portable unit.

16. The system of Claim 15 further comprising: rechargeable battery means in said portable unit for providing electrical power; charger means for charging said rechargeable battery means, said charger means contained in said station; and circuitry means for monitoring the duration of use of said rechargeable battery.

17. The system of Claim 15 wherein said station further comprises: circuitry means for monitoring a physical parameter indicative of the use of said portable unit and for generating data; and means for retaining the said monitored data.

18. The system of Claim 17 wherein said station further comprises: means for extracting said monitored data from said means for retaining; means for retaining a use history of said portable units.

19. A method for assessing the use of a portable monitored unit, comprising: installing an identification circuit in said monitored unit; establishing a station to which said monitored unit must be returned, said station including data processing computing capability; receiving at least a portion of said monitored unit in a defined area of said station; interrogating said identification circuit in said monitored unit to identify the monitored unit; and generating a report on the interrogation and the physical parameter measurement of said monitored unit.

20. The method of Claim 19 further comprising: measuring a physical parameter indicative of the use of said monitored unit.

21. The method of Claim 19 further comprising: correlating a use of said monitored unit with data parameters entered via a user interface; and generating a report of the correlated use and the entered data parameters.

22. The method of Claim 19 further comprising: generating an invoice based upon the duration of use of said monitored unit.

23. The method of Claim 19 further comprising: means for determining whether said monitored unit has been used during a period of time during which said monitored unit was separated from said station.

24. A system for assessing the use of a portable monitored unit, comprising: an identification circuit including within said monitored unit; a station including data processing computing capability, said station also including means for interrogating said identification circuit in said monitored unit; and means for interconnecting said monitored unit and said station;