Abstract:
An integrated system for certifying the safety and efficacy of intravenous (“IV”) pumps is provided wherein a test station having a first component in liquid flow communication with a pump to be tested and a second component adopted for electrical connection to the pump can be operated accurately by persons without extensive technical training and without the need to ship the IV pump off-site. In a preferred embodiment, an output element prompts the operator to input responses based upon a prescribed test protocol to certify the safety and efficacy of the IV pump&#39;s operation.

Description:
RELATED APPLICATIONS 
     This application is a division of co-pending U.S. application Ser. No. 09/225,579 filed Jan. 5, 1999 now abandoned, which is a division of Ser. No. 08/912,177 filed Aug. 15, 1997 now abandoned and Ser. No. 08/911,885 filed Aug. 15, 1997 now abandoned; which is a division of Ser. No. 08/535,544 filed Sep. 28, 1995 (now U.S. Pat. No. 5,742,519 issued Apr. 21, 1998); which is a division of Ser. No. 08/293,537 filed Aug. 19, 1994 (now U.S. Pat. No. 5,856,929 issued Jan. 5, 1999). 
    
    
     FIELD OF THE INVENTION 
     The invention relates to systems and methods for testing the physical, functional, and electrical performance of pumps. 
     BACKGROUND OF THE INVENTION 
     There are many types and styles of pumps intended to administer liquids, medications, and solutions intravenously. Such pumps (commonly called “IV pumps”) operate in various ways; for example, by syringe, diaphragm, peristaltic, and fluid pressure action. 
     Because of their intended use, IV pumps must meet stringent requirements for accuracy and safety. IV pumps also require periodic certification of their physical, functional, and electrical performance characteristics. 
     Today, testing and certification of IV pumps are typically performed by facilities with trained technical staffs. The pump owner loses use of the pump during shipment of the pump to the test facility, and while the pump facility performs its services and ships the pump back. 
     There is a need for a system that a non-technical person can conveniently use to test and completely certify IV pump performance on site, without assistance of often distant test facilities. 
     SUMMARY OF THE INVENTION 
     One aspect of the invention provides a system that integrates in a straightforward and user-friendly manner the testing of different functional and performance characteristics of intravenous pumps. 
     In a preferred embodiment, the system includes a test station and a controller. The test station houses two functional components. The first component is adapted to be coupled in liquid flow communication with an external intravenous fluid pump. The second component is adapted to be coupled electrically to the pump. The controller operates the test station in two modes. In one mode, the first component is operated to test at least one specified liquid flow characteristic of the pump. In the other mode, the second component is operated to test at least one specified electrical safety characteristic of the pump. The controller generates a first test output regarding the specified liquid flow characteristic tested. The controller also generates a second test output regarding the specified electrical safety characteristic tests. In this way, the controller integrates not only the carrying out of the different tests, but the generation of the test results as well. 
     Another aspect of the invention provides a system for carrying out in a stepwise and orderly fashion one or more visual inspections of a functional element of an intravenous pump. This aspect of the invention provides a system having an output element for prompting an operator and an input element for receiving responses from the operator to prompting by the output element. The system also includes a controller coupled to the output element and the input element. The controller generates a prescribed test prompt that instructs the operator to visually inspect at least one specified functional element of the pump. The controller also governs the receipt of a test response from the operator to the test response. The controller generates a test output regarding the specified functional element based upon the test response. 
     The two just discussed aspects of the invention can be combined in an integrated multi-test system. In a preferred embodiment, a system includes a test station housing either a first component adapted to be coupled in liquid flow communication with an external intravenous fluid pump or a second component adapted to be coupled electrically to the pump, or both. The system also includes a controller coupled to the test station. The controller includes an output element for prompting an operator and an input element for receiving response from the operator to prompting of the output element. The controller operates the test station in one mode controlling the operation of the first component to test at least one specified liquid flow characteristic of the pump, or the second component to test at least one specified electrical safety characteristic of the pump, or both. The controller also operates the input and output elements in another mode to generate a test prompt instructing the operator to inspect at least one specified functional element of the pump and to receive a test response from the operator to the test prompt. The controller generates integrated test results. Test outputs concern the specified liquid flow and/or electrical characteristics tested by the test station. Another test output concerns the specified functional element based upon the visual test responses of the operator. 
     In preferred embodiments of these various aspects of the invention, the specified liquid flow characteristic includes liquid flow rate and liquid occlusion pressure. 
     In these preferred embodiments, the system also includes a reporting station coupled to the controller for communicating at least one of the test outputs on alpha or numeric or alpha-numeric format. The controller also preferably includes memory for storing at least one of the test outputs in a database and means for sorting the database according to specified criteria and generating a sorted output, which can be reported in alpha or numeric or alpha-numeric format. 
     Another aspect of the invention provides a system for testing and certifying an intravenous fluid pump. The system includes a test station adapted to be coupled to the pump and a processing station coupled to the test station. The processing station has memory for storing in a database a desired operating characteristic for the pump coupled to the test station. The processing station also includes a controller for operating the test station to obtain an actual operating characteristic measured by operating the pump while coupled to the test station. A comparator in the processing station compares the actual operating characteristic to the desired operating characteristic and generates a certification output based upon the comparison. 
     In a preferred embodiment, the system includes a reporting station for communicating the certification result in alpha or numeric or alpha-numeric format in a certification report. The reporting station also preferably communicates the actual operating characteristics in alpha or numeric or alpha-numeric format in a test results report. 
     The systems following the various aspects of the invention, alone or in combination, make it possible for non-technical people to perform testing and recertification of IV pumps on site at pump distribution centers and hospitals. The systems eliminate the need to send IV pumps to specialized bio-medical facilities for certification. In this way, the systems avoid lost time and expense due to shipping, staging time at the certification facility, and returning the certified pumps to inventory. 
     Other features and advantages of the inventions are set forth in the following specification and attached drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of an integrated system for testing and certifying the physical, functional and electrical performance of IV pumps, which embodies the features of the invention; 
     FIG. 2 is a perspective view of the system shown in FIG. 1 configured as a testing and certifying network simultaneously serving multiple test stations; 
     FIG. 3 is a front right perspective view of the test station associated with the system shown in FIG. 1; 
     FIG. 4 is a right side elevation view of the testing station shown in FIG. 3, showing the interior of the wet chamber, where liquid conveyance testing is accomplished; 
     FIG. 5 is a left side elevation view of the testing station shown in FIG. 3, showing the interior of the dry chamber, where electrical safety testing is accomplished; 
     FIG. 6A is a front elevation view of the testing station, with the front panel broken away in sections to further show the interior of the dry chamber where electrical safety testing is accomplished; 
     FIG. 6B is a schematic view of the first circuit board housed within the dry chamber, which carries the components for testing the electrical safety of an IV pump; 
     FIG. 6C is a schematic view of the second circuit board housed within the dry chamber, which carries a microprocessor and other components for controlling liquid flow and electrical tests upon an IV pump; 
     FIG. 7 is a front section view of the integral valve block that serves as the inlet valve station for the wet chamber of the testing station; 
     FIG. 8 is side section view of the integral valve block shown in FIG. 7, taken generally along lines  8 — 8  in FIG. 7; 
     FIG. 9 is a top view of the liquid detection pad housed within the wet chamber of the testing station; 
     FIG. 10 is a schematic block view of the principal elements comprising the host processing station, the test station, and the data reporting station of the system shown in FIG. 1; 
     FIG. 11A is a schematic flow chart showing the operation of the host station CPU after start up and during the loading of the host program; 
     FIG. 11B is a schematic flow chart showing the operation of the host program in implementing a test and certification procedure; 
     FIG. 11C is a schematic flow chart view showing the operation of the host program in generating reports; 
     FIGS. 12A and 12B, collectively referred to hereinafter as FIG. 12 are a representative excerpt of the Pump Specification Database that forms a part of the host CPU; 
     FIG. 13 is a representative Master Test Listing Database that forms a part of the host CPU; 
     FIG. 14A is a representative Test Matrix that the host program generates based upon correlating the Pump Specification Database; 
     FIG. 14B is a representative Master Test Listing Database; 
     FIG. 15 is a side elevation view of the wet chamber of the test station, largely in schematic form, during the performance of a flow rate accuracy test; 
     FIG. 16A is a side elevation view of the wet chamber of the test station, largely in schematic form, during the performance of an upstream occlusion pressure test; 
     FIG. 16B is a side elevation view of the wet chamber of the test station, largely in schematic form, during the performance of a downstream occlusion pressure test; 
     FIG. 17 is a side elevation view of the wet chamber of the test station, largely in schematic form, during the draining of the test station after performance of the liquid conveyance tests; 
     FIG. 18 is a schematic flow chart showing the operation of the host program in burst filtering load cell weight samples to derive an average weight measurement for use in determining flow rate accuracy; 
     FIG. 19 is a schematic flow chart showing the operation of the host program in determining whether the pump undergoing testing meets the overall flow rate accuracy tests; 
     FIG. 20A is a schematic flow chart showing the operation of the host program in determining whether a pump undergoing testing passes the upstream occlusion tests; 
     FIG. 20B is a schematic flow chart showing the operation of the host program in determining whether a pump undergoing testing passes the downstream occlusion tests; 
     FIG. 21 is a representative Pump Certification Report generated by the host program based upon information containing in the log file database; 
     FIG. 22 is a representative Pump Failure Report generated by the host program based upon information containing in the log file database; 
     FIG. 23A is a representative Detailed Test Result Report generated by the host program based upon information containing in the log file database, detailing the tests conducted and the results; 
     FIG. 23B is a representative Detailed Test Result Report generated by the host program based upon information containing in the log file database, detailing the data collected during the flow rate accuracy tests for a two channel pump; 
     FIG. 24A is a visual test menu used in a preferred implementation of the host program; 
     FIG. 24B is a help screen for the visual test menu shown in FIG. 24A, used in a preferred implementation of the host program; 
     FIG. 25 is a visual real time display of the flow rate accuracy test used in a preferred implementation of the host program; 
     FIG. 26A is a visual real time display of the occlusion pressure test used in a preferred implementation of the host program; 
     FIG. 26B is a visual real time display of the occlusion alarm time test used in a preferred implementation of the host program; 
     FIG. 27 is a visual display of the test results score card used in a preferred implementation of the host program; 
     FIGS. 28A and B are schematic views of the components carried on the first circuit board (shown schematically in FIG. 6A) used to test the electrical safety characteristics of an IV pump. 
    
    
     The invention may be embodied in several forms without departing from its spirit or essential characteristics. The scope of the invention is defined in the appended claims, rather than in the specific description preceding them. All embodiments that fall within the meaning and range of equivalency of the claims are therefore intended to be embraced by the claims. 
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 shows an integrated system  10  for testing and certifying the physical, functional and electrical performance of pumps intended to administer liquids, medications, and solutions intravenously. Such pumps (commonly called “IV pumps”) operate in various ways; for example, by syringe, diaphragm, peristaltic, and fluid pressure action. Because of their intended use, IV pumps must meet stringent requirements for accuracy and safety. IV pumps also require periodic certification of their physical, functional, and electrical performance characteristics. The system  10  serves just such a purpose. 
     The system  10  includes a host processing station  12 , a test station  14 , and a data reporting station  16 . 
     As FIG. 1 shows, the stations  12 ,  14 , and  16  are preferably arranged side-by-side as modules on a work station  18  next to the IV pump  20  that is to be tested and certified. As FIG. 1 also shows, the IV pump  20  is supported on a conventional movable stand and IV pole assembly  22 . 
     As FIG. 1 shows, the test station  14  is adapted to be coupled electrically to the AC power cord  174  of the pump  20  (if the pump  20  is AC powered). The test station  14  carries an AC outlet plug  144  for this purpose. The test station  14  also includes a ground probe  142  that, in use, is coupled to a suitable ground connection on the pump  20 . 
     As FIG. 1 also shows, the test station  14  is adapted to be connected in liquid flow communication with the disposable fluid administration set  168  of the IV pump  20 . The test station  14  carries a female luer connector  64  for this purpose, which mates with a conventional male luer commonly carried on the distal end of fluid administration sets  168 . 
     The host processing station  12  includes a central microprocessing unit (CPU)  24 . The CPU  24  is linked to the test station  14  by a conventional serial connection cable  32  (using, for example, a conventional RS-232 interface). 
     The host processing station  12  also includes an interactive interface  154  for the operator. The interface  154  includes a display screen  26  (for example, a graphics display monitor or CRT), keyboard  28 , and a mouse  30 . 
     As will be described in greater detail later, the host CPU  24  executes a resident host program  160  (see FIGS.  10  and  11 A/B/C). Through the host program  160 , the CPU  24  generates and then implements an integrated test and certification procedure (which will also be referred to as a test matrix  162 , as FIGS.  14 A/B show). The host program  160  preferably customizes the test matrix  162  according to specifications of the particular IV pump that is tested. For this purpose, the host CPU  24  retains pump specifications in an onboard specification database  156  (see FIG.  12 ). The test matrix  162  integrates a battery of visual physical tests, liquid flow and pressure tests, and electrical safety tests for the pump  20  into one consolidated test and certification procedure. 
     In the illustrated and preferred embodiment, the integrated test and certification procedure includes a series of physical inspection tests performed on the pump  20  by the operator under the prompting and control of the host program  160 . The integrated test and certification procedure also includes a series of flow rate accuracy tests, occlusion pressure tests, and (for AC powered pumps) electrical safety tests performed on the pump  20  by the test station  14  under the control of the host CPU  24  with assistance from the operator, when prompted by the host program  160 . 
     In the illustrated and preferred embodiment (as will also be described later in greater detail), the host program  160  uses a graphical interface to display test status information and operator prompts on the display screen  26  as the test procedure progresses. The host interface allows the operator to interact by entering commands and responding to interface prompts, using the keyboard  28  or mouse  30 . In this way, the host program leads the operator in a logical, stepwise fashion through the integrated test and certification procedure. 
     The automated and user-friendly nature of the interface makes possible the use of the system  10  by non-technical people to perform testing and recertification of IV pumps on site at pump distribution centers and hospitals. The system  10  eliminates the need to send IV pumps to specialized bio-medical facilities for certification. In this way, the system  10  avoids lost time and expense due to shipping, staging time at the certification facility, and returning the certified pumps to inventory. 
     In the illustrated and preferred embodiment (as will be described later in greater detail), the host CPU  24  also retains a log file database  164  for each IV pump tested (see FIG.  11 B). The log file database  164  identifies each pump tested by make, model, and an unique alpha-numeric designation. The log file database  164  holds the historical results of each test and certification procedure conducted for each individual IV pump. The log file database  164  provides full documentation for generating a diverse number of performance and tests reports for management, certification, and failure diagnosis purposes. 
     A conventional parallel or serial connection cable  34  links the data reporting station  16  to the host CPU  24 . In the illustrated and preferred embodiment (as FIG. 1 shows), the reporting station  16  is a dot matrix or laser printer. The host program  160  draws from the log file database  164  to transmit to the printer  16  the processed test and certification results. The printer  16  prints these reports in easily understood, preformatted reports (see FIGS. 22 to  23 ). As FIG. 2 shows, the host processing station  12  preferable employs conventional real-time multi-tasking. This allows the host processing station  12  to allocate CPU cycles to different application tasks and simultaneously control multiple test stations  14  in a test and calibration network  11 . 
     The illustrated embodiment in FIG. 2 shows, by way of example, the host processing station  12  simultaneously controlling up to four test stations, designated  14 ( 1 );  14 ( 2 );  14 ( 3 ); and  14 ( 4 ), each associated with an individual IV pump, respectively designated  20 ( 1 );  20 ( 2 );  20 ( 3 ); and  20 ( 4 ). Of course, the host processing station  12  could be conditioned to simultaneously control more test stations  14 , if desired. 
     The principal components of the system  10  will now be individually discussed in greater detail. 
     I. The Test Station 
     As FIG. 3 best shows, the test station  14  includes a compact housing  36 , which can be made from formed metal or molded plastic material. The test station  14  integrates within the housing  36  the testing of both electrical safety and liquid conveyance characteristics of the IV pump  20 . 
     More particularly, the test station  14  physically isolates these two very different test functions by internally compartmentalizing the housing by a dividing plate  38 . The dividing plate  38  creates two side-by-side chambers  40  and  42  within the test station  14 . 
     One chamber  40  occupies the right front side of the housing  36 . This chamber  40  (also shown in side view in FIG. 4) is dedicated to the handling of liquid conveyed by the IV pump  20 . In the illustrated and preferred embodiment shown in FIG. 4, this chamber  40  holds the components that perform liquid flow rate and liquid pressure occlusion tests on IV pumps. For this reason, the chamber  40  will also be called the “wet chamber.” 
     The other chamber  42  occupies the left front side of the housing  36 . This chamber  42  (also shown in front and side views in FIGS. 5 and 6) is dedicated to the handling of high voltage electrical flow to and from AC power IV pumps  20 . In the illustrated and preferred embodiment shown in FIGS. 5 and 6, this chamber  42  holds components for handling electrical output to perform a range of electrical safety tests for AC power IV pumps. For this reason, the chamber  42  will be also called the “dry chamber.” 
     The dividing plate  38  shields the electrical components in the dry chamber  42  from exposure to liquid handled in the wet chamber  40 . The dividing plate  38  thereby isolates within the test station housing  36  all high voltage electrical components from all liquid handling components. 
     A. The Wet Chamber 
     The wet chamber  40  (see FIG. 4) contains a conventional load cell  44  housed within a bracket  46  mounted to the dividing plate  38 . A representative load cell  44  that can be used for this purpose is manufactured by HBM Incorporated, Marlboro, Mass. (Model No. LPX-2XX109). 
     The load cell  44  supports a liquid collection bottle  48 . Preferably, the interior volume of the bottle  48  is sufficiently large to collect liquid during flow accuracy measurements without filling. For most test purposes, a bottle  48  with a volume of about 250 cc should be adequate. Still, as will be described in greater detail later, the test station  14  can be operated to drain the bottle  48 , if required, during a given test procedure, and the test procedure resumed with an emptied bottle  48 . 
     The wet chamber  40  also contains an inlet valve station  50  and a drain valve station  52  mounted to the dividing plate  38 . First and second solenoids  54  and  56  are, in turn, carried by the valve stations  50  and  52 . Under the direction of the host program, the host CPU  24  independently operates the solenoids  54  and  54  to control fluid flow through the respective valve stations  50  and  52  to carry out flow accuracy and occlusion pressure tests. 
     The inlet valve station  50  is configured as a two way valve and includes three branches  58 ,  60 , and  62 . The first branch  58  communicates with the female luer  64  mounted on the front panel  66  of the test station housing  36 . A male luer (not shown) carried at the distal end of the IV pump tubing  168  makes an interference fit within the female luer  64  to connect the pump tubing  168  to the valve station  50 . The inlet valve station  50  is therefore directly subject to pumping pressure applied by the associated IV pump. 
     The second branch  60  of the inlet valve station  50  communicates with a conventional pressure transducer  70 , which is also carried within the wet chamber  40 . The third branch  62  of the inlet valve station  50  communicates with a first length  72  of flexible tubing extending within the wet chamber  40 . The flexible tubing  72  is preferably made of an inert flexible plastic material, like plasticized polyvinylchloride. 
     The first solenoid  54  controls the pressurized fluid flow through the inlet valve station  50 , under the direction of the host program, from the female luer  64  (via the first branch  58 ) either to the pressure transducer  70  (via the second branch  56 ) or to the first tubing  72  (via the third branch  62 ). The first solenoid  54  is normally spring biased to open liquid flow between the first branch  58  (from the female luer  64 ), the second branch  56  (to the pressure transducer  70 ), and the third branch  62  (to the first tubing  72 ). In this condition, pressurized liquid flows, following the path of least resistance, through the inlet valve station  50  from the female luer  64  to the drain valve station  52 . 
     The first solenoid  56  can be activated, under the control of the host program independent of activation of the second solenoid  56 , to close liquid flow between the first branch  58  (from the female luer  64 ) and the third branch  62  (to the first tubing  72 , leading to the drain valve station  52 ). This condition channels all pressurized liquid flow from the first branch  58  into the second branch  60 . The resulting increase in pressure in the second branch  60  is detected by the pressure transducer  70 . 
     A representative commercially available solenoid that can serve as the first solenoid  54  is made of NR Research Inc., Northboro, Mass. (Model Number HP225T021). 
     The drain valve station  52  is configured as a three way valve and also includes first, second, and third branches  74 ,  76 , and  78 . The first branch  74  communicates with the first tubing  72  leading from the inlet valve station  50 . The second branch  76  communicates with a second length  80  of tubing extending within the wet chamber  40 , which is also preferably plasticized polyvinylchloride plastic material. The second tubing  80  leads in an iso-radial path from the drain valve station  52  to the collection bottle  48 . The third branch  78  communicates with a drain tube  82  for the wet chamber  40 . The drain tube  82  exits the wet chamber  40  through an opening  84  in the bottom panel  86  of the test station housing  36 . The drain tube  82  is also preferably plasticized polyvinylchloride plastic material. 
     A second solenoid  56  controls fluid flow through the drain valve station  52 , under the direction of the host program, from the first tubing  72  (via the first branch  74 ) either to the collection bottle  48  (via the second branch  76  and tubing  80 ) or to drain tube  82  (via the third branch  78 ). 
     The second solenoid  56  is normally spring biased to open liquid flow between the first branch  74  (from the first tubing  72 ), and the second branch  76  (to the second tubing  80  leading to the collection bottle  48 ), while closing liquid flow through the third branch  78  (to the drain tube  82 ). In this condition, the drain valve station  52  directs liquid from the inlet valve station  50  to the collection bottle  48 . By sensing with the load cell  44  the change in weight of the bottle  48  over time, and knowing the specific gravity of the liquid being conveyed, the host program  160  derives a flow rate calculation gravimetrically. 
     The second solenoid  56  can be activated, under the control of the host program  160 , independent of activation of the first solenoid  54 , to open liquid flow between the second branch  76  (from the second tubing  80  leading from the collection bottle  48 ) and the third branch  78  (to the drain tube  82 ). This allows liquid in the bottle  48  to drain by gravity pressure through the drain tube  82 . If the IV pump  20  is still operating and the first solenoid  54  is not activated, pressurized liquid flowing from the inlet valve station  50  will also follow the path of least resistance through the drain tube  82 . 
     A representative commercially available solenoid that can serve as the first solenoid is made of NR Research Inc., Northboro, Mass. (Model Number 648T031). 
     In the illustrated and preferred embodiment (see FIGS.  7  and  8 ), the inlet valve station  50  minimizes the number of high pressure, leak-prone connections by consolidated them into integral valve block  88  attached to the dividing plate  38 . The valve block is made of an inert plastic material that makes leak resistant threaded connections, like Teflon plastic. The block  88  contains drilled interior passageways that comprise the first, second, and third branches  58 ,  60 , and  62 , already described. The first branch passageway  58  joins the second branch passageway  60 , and together they join an orifice  90  that enters a preformed valve seat  92  on the block  88 . The second branch passageway  60  joins a second orifice  94  that also enters the valve seat  92 . The first solenoid  54  is mounted to the block  88  overlying the valve seat  92 . In its normally biased, inactivated position, the first solenoid  54  is withdrawn from the valve seat  92 . This allows liquid flow through the valve seat  92  between the orifices  90  and  92 , through the first and second branch passageways  58 / 60  into the third branch passageway  62 . When activated, the first solenoid  54  seats inside the value seat  92 , blocking the orifices  90  and  92  and thereby blocking the liquid flow between them. The pressurized flow thereby collects in the second branch passageway  56  for pressure detection by the pressure transducer  70 . 
     The first, second, and third branch passageways  58 ,  60 , and  62  include internally threaded ports  96  that mate with threaded connectors  98  on the female luer  64 , the pressure transducer  70 , and the first tubing  72 . Consolidated, secure, and leakproof conveyance of liquid through the valve station block  88  results. 
     While not shown, a similar integral block construction could be used to form the drain valve station  52 , or to consolidate the inlet and drain valve stations  50  and  52  into a single valve block. 
     In the illustrated and preferred embodiment (see FIG.  4 ), the wet chamber  40  includes a liquid spill detection element  100 . The element  100  detects the leakage of liquid within the wet chamber  40 . The leakage, if not detected, could adversely impact the accuracy of the flow rate calculations. 
     The spill detection element  100  can be constructed in various ways. In the illustrated and preferred embodiment (see FIG.  9 ), the spill detection element  100  comprises pad  102  of electrically non-conducting material mounted on the bottom panel  86  of the wet chamber  40 . Various non-conducting materials can be used. In the illustrated and preferred embodiment, the pad  102  is made of a polyester material. 
     First and second circuits  104  and  106  of electrically conducting material, like copper, are applied by coating or by etching or by imbedding thin wires on the pad  102  (see FIG.  9 ). The first and second circuits  104  and  106  form an array of spaced apart fingers  108 , which are nested in an alternating pattern on the pad  102 . 
     The first and second circuits  104  and  106  are normally insulated from each other by the pad material between the alternating fingers  108 , so that the first and second circuits  104  and  106  normally conduct no current between them. The presence of one or more liquid droplets on the pad  102  spanning across the alternating fingers  108  electrically connects the first and second circuits  104  and  106  to conduct current and illuminate an LED  110  on the front panel  66  of the test station housing  36  (see FIG.  3 ). When illuminated, the LED  110  alerts the operator to the leakage of liquid within the wet chamber  40 . 
     When the pad  102  senses liquid leakage, a signal is also relayed to the host CPU  24  indicating the problem. The host CPU  26  also displays a “liquid leakage” message on the screen  26  (and preferably also sounds an audible alarm) to alert the operator. 
     As FIGS. 3 and 4 show, the right side of the test station housing  36  includes a door  112  mounted on a piano hinge  114 . The door  112  opens and closes to provide access to the wet chamber  40 . A conventional magnetic release latch  116  (see FIG. 4) normally holds the access door  112  closed during use. 
     In the illustrated and preferred embodiment (as FIG. 4 shows), the interior of the access door  112  includes a bracket  118  that carries weights (designated W1 and W2 in FIG. 4) of predetermined size. Upon prompting by the host program  160 , the operator opens the access door  112  and places one or more of the weights W1/W2 upon the collection bottle  48  to calibrate the load cell  44 . The details of this calibration process governed by the host program  160  will be described later. 
     In a preferred embodiment, the test station housing  36  includes a conventional proximity sensor  120  (see FIG. 4) to sense when the access door  112  is opened. The host program  160  appropriately prompts the operator with an “Open Door” indication in response to a signal relayed to it from the proximity sensor  120 . Upon receiving an “Open Door” signal from the sensor  120 , the host CPU  24  preferably also aborts any tests involving components in the wet chamber  40 . Upon closing the access door  112 , the host CPU  24  restarts an aborted test from the beginning. 
     It should be realized that flow accuracy measurements could be accomplished in ways different than gravimetrically. For example, the wet chamber  40  could include a fixed volume capillary tube and photosensors to measure flow rates volumetrically. Because the capillary tube becomes partially or totally occluded by bacterial growth or liquid residue within it, volumetric systems are prone to inaccuracies and results that are not uniformly repeatable, For this reason, the gravimetric method for measuring flow rates is preferred. 
     B. The Dry Chamber 
     Please refer now to FIGS.  5  and  6 A/B/C. The dry chamber  42  houses on three integrated circuit boards  122 ,  124 , and  124  the numerous components that assist in the acquisition and processing of electrical data by the test station  14 , as well as the communication of this data to the host CPU  24 . A left side panel  128  closes the dry chamber  42 , protecting the boards  122 ,  124 , and  126  from direct access and exposure to the outside environment. As before stated, the dividing panel  38  protects the boards  122 ,  124 , and  126  from unintended contact with liquid in the wet chamber  40 , and vice-versa. 
     Spacers  130  attach the first circuit board  122  to the dividing panel  38  (see FIG.  6 A). The first circuit board  122  (shown schematically in block form in FIG. 6B) carries the various relays and electrical components  68  needed to check internal and external electrical leakage in the IV pump  20  with normal and reverse polarities, with and without ground, and with and without AC power applied. Further details of the electrical components  68  and their operation will be described later. 
     The first circuit board  122  includes a low voltage AC (115V) power supply PS 1 . This power supply PS 1  powers the relays and electrical components  68  on the board  122 , the solenoids  50  and  52  in the wet chamber  40 , and the serial port interface  188  between the host CPU  32  and the test station microprocessor  132  (mounted on the second circuit board  124 ). 
     The second circuit board  124  is attached by additional spacers  130  to the first circuit board  122  in the dry chamber  42  (see FIG.  6 A). The second circuit board  124  (shown schematically in block form in FIG. 6C) carries a microprocessor  132  (for example, a type 8032BH) for implemented tasks under the control of the host CPU  24 . The second circuit board  124  includes the serial interface  188  (for example, a type MAX232) through which the host CPU  32  and test station microprocessor  132  communicate. 
     The second circuit board  124  also includes a static RAM block  176  (for example, a type 6264) for use by the microprocessor  132 . The board  124  also carries a battery backed RAM block  178  (for example, a type 2816) for retaining information pertaining to the use and maintenance of the test station  12 , which will be described in greater detail later. The board  124  also includes a programmable ROM block  180  (for example, a type 27C64). The ROM block  180  contains imbedded software that the host software  160  programs to instruct the microprocessor  132  to carry out prescribed test and certification procedures. 
     The second circuit board  124  carries the low voltage DC power (5 V) supply PS 2  for the components on the second circuit board  124 . As will be described in greater detail later, optical-isolation elements  198  carried on the first board  122  electrically isolate the low voltage components on the second board  124  from the high voltage electrical components  68  on the first board  122  and the solenoids  50 / 52 . The control signals from the test station microprocessor  132  are channeled through the optical-isolators and decoded by decoders  202  before being sent to the drivers  204  for the relays  68  on the first board  122 . 
     Likewise, optical-isolation elements  198  on the second board  124  electrically isolate the serial port interface  188  from its power supply PS 1  carried on the first board  122 . 
     The static RAM block  176 , battery backed RAM block  178 , and the ROM block  180  communicate with the microprocessor  132  via an address bus  182  and a data bus  184 . Implementing the program in imbedded software, the test station microprocessor  132  transmits control signals through an I/O buss  186  (for example, a type 82C55) to activate the first and second solenoids  54 / 56  and the electrical components  68  on the first circuit board  122 , as well as receive data signals from the electrical components  68 , the pressure transducer  70 , and the load cell  44 . The second circuit board  124  carries an analog-to-digital (A-to-D) converter  190  (for example, a type ICL7135) that converts the analog signals of the pressure transducer  70 , the load cell  44 , and the electrical components  68  on the first board  122  to digital signals for processing by the host CPU  24 . The analog signals are conditioned and amplified by conventional front end conditioning circuits  192  on the second board  124 . The conditioned analog signals are also preferably channeled through an analog multiplexer  194  (for example, a type 4051), which selects the analog signal to be converted by the converter  190 . The digital output of the A-to-D converter  190  passes through a decoder  196 , if necessary to assure compatibility with the microprocessor bus  186 . The digital output is transmitted by the microprocessor  132  to the host CPU  32  for processing. 
     The second circuit board  124  also includes a watchdog  200  that alerts the operator should the microprocessor  132  fail during use. The details of the watchdog  200  will be described later. 
     The third circuit board  126  drives LED&#39;s exposed on the front panel  66  of the test station housing  36 . The number and function of the LED&#39;s can vary. The illustrated and preferred embodiment provides five LED&#39;s (see FIG. 3 as well). 
     A status LED  134  identifies the test station  14  by a number 1 to 4 (when multiple test stations are being used), and blinks when tests are underway. 
     The moisture detection LED  110  (already described) illuminates when the spill detection element  100  in the wet chamber  40  senses liquid leakage. 
     A communication fault LED  136  illuminates when the communication link between the host processing station  12  and the test station  14  breaks down. 
     A device fault LED  138  illuminates when general electrical or logic failures in the test station circuitry are sensed. 
     A test power LED  140  illuminates when the outlet plug  144  of the test station  14  receives power. 
     Cables  142  lead around the dividing panel  38  between the dry and wet chambers  40  and  42  to electrically connect the first and second solenoids  54 / 56 , the pressure transducer  70 , the load cell  44 , the spill detection element  100 , and the proximity sensor  120  to the circuit boards  122 ,  124 , and  126 . Additional cables  142  also electrically connect a test station power plug  144  (mounted to the front panel  66  of the test station housing  36 ) and a ground probe  146  to the circuit boards  122 ,  124 , and  126 . In routing the electrical cables  142 , high voltage lines are kept separate from low voltage lines. 
     Two resistance studs (designated S 1  and S 2 ) mounted on the dividing panel  38  extend into the wet chamber  40  (see FIGS.  4  and  6 ). The studs S 1  and S 2  are electrically connected to the boards  122 ,  124 , and  126  in the dry chamber  42  to present different, known resistance values for conducting periodic ground resistance calibration at the prompting of the host CPU  24 . The particularities of these calibration tests will be described later. 
     C. Start Up and Safety Checks 
     Preferably, the operator allows the test station  14  to warm up for a predetermined time (e.g. 5 minutes) before use. This warm up period allows the load cell  44  and other electrical components to stabilize before use. 
     The status LED  134  preferably displays a “−” indication or the like during the warm up period. After the warm up period, the status LED  134  displays the test station number. The displayed test station number is constant when the test station is on line but not being used to conduct a test. The displayed test station number blinks when the test station is on line and conducting a test, as previously described. 
     During power up, the test station microprocessor  132  runs a prescribed series of self tests during warm up to assure that communications with the host processing station  12  exists and that no general electrical or logic failures are present in the test station circuitry, including using checksum for battery backed RAM data. The test station microprocessor  132  illuminates the device fault LED  138  when general electrical or logic failures in the test station circuitry are sensed. 
     The test station microprocessor  132  also preferably includes a watchdog  200 , as previously discussed. The watchdog  200  automatically interrupts operation of the test station  12  and initiates a power up routine after a given time-out period (for example 1.5 seconds), unless the watchdog receives a specified flag signal from the imbedded software on the second board  124 , which resets the time-out period. When the microprocessor  132  is functioning properly, the watchdog  200  periodically receives the flag signal (for example, once every 0.5 second) to prevent its timing out. When the microprocessor  132  fails, the absence of the flag signal allows the watchdog  200  to time-out, initiating a power up routine to initiate the series of self-tests to identify the electrical or logic failure. 
     The test station microprocessor  132  also illuminates the communication fault LED  136  should communication with the host station  12  fail to be detected. The LED  136  goes off whenever communication occurs between the test station microprocessor  132  and the host CPU  24 . Likewise, if communication is garbled, causing frequent transmissions and retransmissions, the LED  135  will flicker. 
     In addition, the host CPU  24  sends a periodic “heartbeat” signal to the test station microprocessor  132 . The “heartbeat” signal causes the test station microprocessor  132  to transmit an elapsed test time signal. If the microprocessor  132  does not respond to the “heartbeat” signal, the host CPU  24  alerts the operator that communication with the test station  12  has broken down. 
     II. The Host Processing Station 
     A. The Host CPU 
     The host CPU  24  acts as the master of the system  10 , initiating all of the control functions. The test station microprocessor  132  is slaved to the host CPU  24 , as is the data reporting station  16 , which respond to the control functions that the CPU  24  initiates. The host CPU  24  communicates with the test station microprocessor  132  and the data reporting station  16 , as previously described. In this way, the host CPU  24  coordinates overall control functions for the system  10 . 
     As FIG. 10 schematically shows, the host CPU  24  communicates with a mass storage device  148  (e.g., a hard drive) and an extended static RAM  150 . Preferable, the RAM  150  includes a battery backup  152 . The user interactive interface  154  (already described) also communicates with the host CPU  24 . 
     The mass storage device  148  retains in non-volatile memory the databases and data processing intelligence to perform and process the intended test and certification procedures. In the illustrated and preferred embodiment (as FIG. 10 shows), the host CPU  24  retains in hard drive memory: 
     (1) a specification database  156  (see also FIG.  12 ), which contains the current physical, functional, and performance specifications of all makes and models of IV pumps that the system  10  is intended to test and certify, which are provided by or derived from the manufacturer&#39;s product specifications. 
     (2) a master test list database  158  (see also FIG.  13 ), which contains all visual, flow rate, occlusion, and electrical safety tests that the system  10  is capable of performing. 
     (3) the executable host program  160 , which generates and implements the test matrix  162  (see FIGS. 14A and B) based upon the unique specifications for the make and model of the IV pump identified for testing by the system  10 . 
     (4) a log file database  164  documenting by make, model, and unique identification designation, each pump tested by the system  10  and the results of each test and certification procedures conducted by the system  10  for each IV pump. 
     (5) a usage database  166  documenting usage of the host processing station and each test station it controls. Usage information can include, for example, the total number of automated test sequences completed by the host station  12 ; and the total number of test and certification procedures performed by each test station  14 , classified according to test type. 
     The test station microprocessor  132  also retains usage information specifically relating to the test station in battery-backed RAM in the imbedded software of the test station microprocessor  132 . This information can be retrieved by the operator upon demand through the host CPU  32 . Representative examples of test station-specific usage information include the total times the test station  12  has been powered up; recent (e.g., the last twenty) test station error alarms; and recent (e.g., the last twenty) test station recalibrations performed by the operator (as will be described later). 
     In the illustrated and preferred embodiment, the host CPU  24  comprises a conventional 486-series microprocessor (33 Mhz or more), with a hard drive  148  having a mass storage capacity of at least 200 mB and RAM  150  of at least 4 mB. 
     B. Host Station Start Up 
     In readying the system  10  for use (as FIG. 1 shows), the operator supplies power to the host processing station  12 , test station  14 , and data reporting station  16 . 
     As FIG. 11A shows, like the test station microprocessor  132 , the host CPU  24  conducts, upon start up, conventional initialization and critical data integrity checks (designated in FIG. 11A as the initialization routine) to verify that its processor and associated electrical components are working, including a checksum for battery backed RAM data. 
     If these power-up tests fail, the host CPU  24  enters a shutdown mode. Otherwise, the CPU  24  loads the host program  160 . 
     Upon execution, the host program  160  prompts the operator to log on by verifying the correct date and time and identifying him or him or herself. Password protection could be implemented at this initial stage of the host program  160  to prevent unauthorized persons from using the system  10 . 
     As FIG. 11A further shows, after log on, the host program prompts the operator to select among (a) Conducting a Test and Calibration Procedure; (b) Generating a Report; or ( 3 ) Exiting the Host Program. 
     C. Conducting a Test and Certification Procedure 
     (1) Pump Identification 
     As FIG. 11B shows, at the outset of each test and certification procedure, the host program  160  requires the operator to identify by make, model, and unique identification number the IV pump  20  to be tested. The operator responds by supplying an alpha-numeric designation unique to each IV pump tested by the system  10 . 
     The designation can comprise the serial number assigned by the manufacturer of the IV pump. Alternatively, the designation can comprise an alpha-numeric sequence assigned by the user or distributor of the IV, or by the operator of the system  10 . 
     The alpha-numeric designation is initially entered by the operator, upon prompting by the host program, by the keyboard  28 . Alternatively, the designation can be entered by scanning the designation affixed in bar code form on a label attached to the pump. Once entered, the host CPU  24  retains the alpha-numeric designation in a file in the log file database  164 . Thereafter, the operator can use the mouse  30  or keyboard  28  to open and scroll through pump identification windows displayed by the host program, which present those pumps recorded in the log file database  164 . The operator can select one of the pumps using the mouse  30  or the keyboard  28 . 
     The log file database  164  automatically generated by the host program  160  creates a historical record of all test and certification procedures conducted on the IV pump by the system  10 , together with the detailed results of each procedure. The log file database  164  holds the log files for each IV pump, uniquely identified by its assigned alpha-numeric designation, thereby documenting the performance records and Pass/Fail diagnoses for all IV pumps tested by the system  10 . It is from the log file database  164  that the host program compiles the performance and tests reports. 
     The automatic maintenance by the host program of the log file database  164  during each test and calibration procedure, coupled with the associated ability to generate reports both at the end of each test and certification procedure and on demand, constitutes an invaluable resource and management tool for the operator. Further details concerning these reports and the execution of host program in creating them will be described later. 
     (2) Generating the Test Matrix 
     As FIG. 11B shows, upon identifying the make, model, and alpha-numeric designation of the pump  20 , the host program  160  creates and executes the test and certification procedure for the identified IV pump. The procedure first draws upon and consolidates information within the pump specification database  156  and the master test listing database  158  to create a test matrix  162  for the pump to be tested. 
     (A) Pump Specification Database 
     FIGS.  12 A/B are a representative excerpt from the specification database  156 , listing the specifications for certain makes and models of commercially used IV pumps. As FIGS.  12 A/B show, the specification database includes not only the functional and performance specifications for the pumps, but also the manufacturers&#39; specifications regarding flow rate accuracy and occlusion pressure. FIGS.  12 A/B show that the specifications can differ significantly among different makes and models of pumps. 
     The specification database  156  can be periodically updated to remain current. 
     (B) Master Test Listing Database 
     FIG. 13 shows a listing of a representative master consolidated test database  158  retained by the host CPU  24 . The host program  160  is capable of prompting the operator and directing the test station microprocessor  132  to implement all the tests in the master test database  158  according to prescribed criteria, as will be described later. 
     (C) The Test Matrix 
     Still, not all tests contained in the master consolidated test database  158  are applicable to all IV pumps. For example, as FIG. 12 shows, many IV pumps conduct liquid using only one pump channel, while other pumps have two pump channels. Therefore, the testing of a second pump channel found in the master database  158  (see Tests  27 ,  28 , and  29 ) is simply not applicable to these pumps. As another example, pumps that are not AC powered do not require the electrical safety tests listed in the master database  158 . 
     Therefore, before proceeding with testing a given IV pump identified by the operator, the host program  160  correlates the information contained in the master consolidated test database  158  based upon the information contained in the specification database  156  for the pump identified for testing. This correlation generates the test matrix  162  (see FIG. 14A) for the identified IV pump. 
     FIG. 14A shows representative text matrixes  162  for the IV pumps contained in the specification database  156  shown in FIGS.  12 A/B, based upon the master test database  158  shown in FIG.  13 . 
     The pump-specific test matrix  162  takes into account the particular functional and performance characteristics of the identified IV pump set forth in the specification database  156 . The matrix  162  selects from the master consolidated test database  158  only those tests that can or should be performed on the identified pump during the test and calibration procedure (see FIG.  14 A). The test matrix  162  also takes into account the accuracy flow rate and occlusion flow rate and pressure data set forth in the specification database  156  for identified pump (see FIG.  14 A). 
     Guided by the test matrix  162  for the particular IV pump identified for testing, the host program  160  proceeds with the test and calibration procedure. As FIG. 11B shows, the procedure advances through visual inspection tests, flow rate accuracy tests, occlusion pressure tests, and electrical safety tests set forth in the pump-specific test matrix  162 . The host program  160  also uses the flow rate accuracy and occlusion flow rate and pressure information specified for that IV pump in the test matrix  162  in setting up and evaluating the flow rate accuracy tests and occlusion pressure tests. The host program  160  also draws upon information in the test matrix  162  to recommend the flow rate for conducting the accuracy tests, as well as the number of flow rate samples that should be taken during the test period. 
     A given IV pump receives an overall PASS result for the test and calibration procedure only if it receives a PASS result for every visual inspection test, every flow rate accuracy test, every occlusion pressure test, and every electrical safety test contained in its test matrix  162 . Otherwise, the IV pump receives an overall FAIL result for the test and calibration procedure. 
     The overall nature of the individual tests on the master list database  158  that are implemented by the host program  160  in the illustrated and preferred embodiment will now be discussed in greater detail. 
     (3) Conducting Visual Inspection Tests 
     The host program  160  carries out visual inspection tests by prompting the operator to operate and/or visually inspect certain physical or functional aspects of the IV pump that are accessible or visible to the operator. 
     The particular aspects of the IV pump identified for operation or inspection in the test matrix  162  during the visual inspection tests can vary according to the particular specifications of the pump. The following is a representative listing of typical visual inspection tests and the associated representative prompts that the host program can use: 
     Unit Clean 
     Host Program Prompt: 
     Ensure the pump is clean of all spilled fluids and other dirt or grime. Check for solution stains in corners and connections between case halves and/or other assemblies. 
     Loose Component (Vibration) Check 
     Host Program Prompt: 
     Listen for loose components moving around the inside of the pump while turning the pump upside down and sideways. 
     During Flow Rate Accuracy testing, check for excessive vibration or other noises emanating from the pump. 
     Keypad &amp; Display Window (Visual Check) 
     Host Program Prompt: 
     Check for cuts, cracks, or holes in the keypad or display window. Check for fluid on the inside of the display window. 
     Ensure that any scuffs or other marks on the display window do not interfere with the correct reading of the display. 
     Case Assembly 
     Host Program Prompt: 
     Visually inspect the pump case for missing or damaged parts including any cosmetic defects. 
     Battery Door Inspection 
     Host Program Prompt: 
     The battery door should slide upward to reveal the battery compartment. Verify some resistance at the start of opening and smooth operation once started. Ensure that the battery diagram symbol with the + and − symbols is firmly in place. 
     Ensure that the battery contact pads are firmly in place. 
     Latch Assembly Inspections 
     Host Program Prompt: 
     Verify smooth operation for the Channel A latch and the Channel B latch. In opening a latch, it should move in an “L” shape by sliding down and then back. To close the latch, slide down, forward and then up. The small tab on the latch assembly should overlap the small tab on the administration set cartage and hold the cartridge in place. 
     Power Up On Battery 
     Host Program Prompt: 
     Install both batteries. Tone alarm will beep and the LCD will display: 
     UNIT SELF TEST 
     IN PROGRESS 
     At the completion of the self-test, the display will then show the results of the last program entered and “STOP.” 
     Ensure all LCD segments are visible. 
     Press the [DISPLAY] key. Verify that backlight is illuminated. 
     Verify that the pump powers on with one battery in either battery position. Shake pump to verify continued battery operation. 
     Try each battery position one at a time. 
     Keypad Functionality 
     Host Program Prompt: 
     Activate each key to ensure it correctly responds and operates. Ensure correct information is displayed with each key activation. Inspect for excessive wear of keys. 
     Prime Buttons Functionality 
     Host Program Prompt: 
     Place pump in priming mode. Depress [PRIME] button followed by pressing and holding the A channel button . . . . Ensure the Channel A motor turns and set priming function is initiated and properly completed. Depress [PRIME] button followed by pressing and holding the B channel button . . . . Ensure the Channel B motor turns and set priming function is initiated and properly completed. 
     Bolus Button Functionality 
     Host Program Prompt: 
     Place pump in bolus delivery mode. Depress bolus button. Ensure bolus delivery is initiated and properly completed. 
     Remote Bolus Cord Functionality 
     Host Program Prompt: 
     Attach Remote Bolus Cord to pump. Verify that display does not change while plug is being inserted. Place pump in bolus delivery mode. Depress remote bolus button. Ensure bolus delivery is initiated and properly completed. 
     Air In Line Detectors 
     Host Program Prompt: 
     Visually inspect for excessive wear or damaged parts on the air detector transmitter and receiver for both Channel A and Channel B. 
     Verify that the air alarm is not defeated. 
     To verify, ensure that each channel is programmed. Press the [DISPLAY] key and note that: 
     “AIR IN LINE *A” 
     “ALARM ON” 
     and 
     “AIR IN LINE *B” 
     “ALARM ON” 
     is displayed on the screen. 
     Enter air bubble into administration set above the pump mechanism for Channel A. Air bubble size must be greater than 50 to 100 microliters. Ensure air bubble is detected and that the air alarm is properly indicated by “AIR” in the display and is accompanied by a beeping tone alarm. 
     Clear the alarm. Enter air bubble into administration set above the pump mechanism for Channel B. Air bubble size must be greater than 50 to 100 microliters. Ensure air bubble is detected and that the air alarm is properly indicated by “AIR” in the display and is accompanied by a beeping tone alarm. 
     Memory Check 
     Host Program Prompt: 
     Remove batteries from pump for 15 seconds. 
     Display should go blank. 
     Reinstall batteries. 
     Following completion of the pump self-test, press the [DISPLAY] key and verify that the previous program is displayed. 
     Proper Labels 
     Host Program Prompt: 
     Visually inspect to ensure no labels are damaged beyond use or exhibit excessive wear. 
     Visually inspect to ensure the pump has attached to it all appropriate product labels in the correct locations. At minimum, this is to include: 
     Name Plate Label 
     Side Logo Label 
     Operating Instructions Label 
     Warranty Void Label 
     Bolus Label 
     Final Visual Inspection 
     Host Program Prompt: 
     Visually inspect the pump to ensure no scratches, blemishes or other physical damage has occurred during the course of testing or was otherwise not noted during previous inspections. 
     Ensure all required labels are present with technician initials and dates where appropriate. 
     If appropriate, attach recertification label. 
     Documentation Complete 
     Host Program Prompt: 
     Ensure all required recertification documents are present. 
     Ensure all required recertification documents are correctly and completely filled in. 
     Ensure signatures are in appropriate areas. 
     Power Up on AC Power 
     Host Program Prompt: 
     Plug the pump power plug into the power receptacle on the Test Station. Connect the ground probe to a chassis grounded conductive part. Turn the pump power switch on. 
     In addition to a visual prompt, the host program  160  may also include a graphic display of information to instruct the operator in performing the visual test. 
     The operator responds to the host program&#39;s prompts individually for each visual test item by indicating compliance (PASS) or lack of compliance (FAIL), using either the keyboard  28  or clicking the mouse  30  to enter information. Preferably, the host program  160  does not proceed with other tests categories on the test matrix  162  until the operator has appropriately responded to all the visual inspection prompts. 
     A preferred implementation of the host program  160  (see FIG. 24A) includes a VISUAL TEST MENU which displays the visual tests and provides Fail and Pass Buttons. The operator makes the selections, as appropriate, by clicking the mouse. 
     This preferred implementation also provides a Detail Button (as FIG. 24A shows), which the operator can click to open a help window (see FIG.  24 A). The help window (which FIG. 24B shows for the Pole Clamp Test) explains to the operator the how the visual and functional inspection should be carried out for the particular test. The Host Program Prompts, listed above, are found in the help windows for their respective test items. 
     Only if all selected visual inspection test items receive a PASS response does the host program  160  register a PASS result for the overall visual inspection test. Otherwise, the host program registers a FAIL result. 
     In a preferred implementation, the VISUAL TEST MENU lists only those tests that can be accomplished before the pump  20  is either electrically coupled to or placed in liquid flow communication with the test station  14 . Tests that are not dependent upon connection to the test station  12  include, for example, Test Numbers 1 to 8 and 11 to 21 in the master test listing database shown in FIG.  13 . These tests are preferably performed at the outset of the test and calibration procedure, with prompting by the host program  160 , while the pump  20  is free of attachment to the test station  14 . Because of this, after completing all required tests, the operator can exit the VISUAL TEST MENU without completing any of the remaining tests in the test matrix  162 . The host program  160  nevertheless establishes and retains in the log file database  164  for that pump the results of the completed visual tests. At a later time, the operator can enter the host program  162  and resume the test and certification procedure for that pump, skipping the visual tests already performed. In this way, an operator having a limited number of available test stations can conduct simultaneously the functional/visual tests on one pump (without attachment to a test station) while another pump (attached to a test station) undergoes testing. 
     (4) Conducting Liquid Conveyance Tests 
     To conduct flow rate accuracy tests and occlusion pressure tests, the pump  20  must be coupled in liquid flow communication with the test station  14 , as well as must be electrically coupled to the test station  14 . 
     The host program  160  prompts the operator to install a primed disposable administration set  168  intended for the IV pump  20 . In carrying out this instruction (see FIG.  1 ), the operator connects the proximal end of the set  168  to a full solution bag  170  suspended above the pump  20  for gravity flow. The operator connects the male luer at the distal end of the set  168  to the female luer  64  on the front panel  66  of the test station housing  36 . The operator also readies the drain tube  82  by routing it from the test station  14  to a suitable drain receptacle  172 . Preferable, the operator is prompted to prime the set using about 2 mL of liquid. 
     If the pump  20  is AC powered, the operator will also be prompted to connect the AC power cord  174  of the IV pump  20  to the power outlet  144  on the front panel  66  of the test station housing  36  (see the Power Up on AC Power Test, described above). At the same time, the operator will further be prompted to connect the ground continuity probe  146  of the test station  14  to a suitable connection site on the IV pump  20 , such as a ground lug or to the handle or the IV pole on the stand  22  carrying the IV pump  20 . 
     (a) Test Station Verification 
     As FIG. 11B shows, at some point before beginning a prescribed liquid conveyance test, the host program  160  preferably verifies that the first and second solenoids  54  and  56  in the wet chamber  40  of the test station  14  are functional, not leaking, and ready for operation. 
     With the first solenoid  54  and second solenoids  56  in their unactivated position (as FIG. 15 generally shows), the host program  160  prompts the operator to turn on the pump  20  to convey fluid into the wet chamber  40 . If the load cell  44  does not sense the expected increase in weight of the bottle  48 , either the first or second solenoids  54 / 56 , or both, are presumed to have failed in their activated positions. 
     The host program  160  can direct the test station microprocessor  132  to supply trouble shooting information to identify the failure mode and prompt the operator accordingly. For example, with minimal pressure sensed by the pressure transducer  70 , the host program  160  deduces the second solenoid  56  as the source of failure. With high pressure sensed by the pressure transducer  70 , the host program  160  deduces the first solenoid  54  as the source of failure. 
     With the first solenoid  54  in its activated position (as FIG. 16B generally shows), the pressure transducer  70  should sense an increase in pressure. If the pressure transducer  70  does not sense this expected pressure increase, the host program  160  deduces that the first solenoid  54  has failed in its unactivated position and prompts the operator accordingly. 
     When the second solenoid  56  is in its activated position (as FIG. 17 generally shows), liquid should drain from the collection bottle  48 , and the load cell  44  should sense a decrease in weight. If the load cell  44  does not sense this expected decrease, the host program  160  deduces that the second solenoid  56  has failed in its unactivated position and prompts the operator accordingly. 
     If either solenoid  54  or  56  has failed in a leaky condition, the spill detector element  100  will sense the presence of liquid. The test station microprocessor  132  senses this condition and relays a “liquid leakage” signal to the host program  160 , which alerts the operator. 
     When these threshold functionality tests indicate the readiness of the test station  14 , the host program  160  proceeds stepwise through the applicable flow rate accuracy tests and occlusion pressure tests. 
     (b) Flow Rate Accuracy Tests 
     The host program  160  carries out the flow rate accuracy tests by operating the pump  20  to convey liquid of a known specific gravity to the collection bottle  48  in the wet chamber  40 , while monitoring the change in weight sensed by the load cell  44  over time. 
     More particularly, as FIG. 15 shows, with the IV pump  20  operating, the host program  160  directs the test station microprocessor  132  to retain the first and second solenoids  54 / 56  in their normal, unactivated conditions. Liquid conveyed by the IV pump  20  flows through the inlet and drain valve stations  50  and  52  into the collection bottle. The test station microprocessor  132  converts the analog weight signals received from the load cell  44  during successive prescribed sample periods to digital weight signals. The digital weight signal from one sample period are compared to the weight signal for a preceding sample period. By assessing the change in weight between the sample periods, and knowing the specific gravity of the liquid being conveyed, the host CPU  24  gravimetrically calculates a flow rate at the end of successive sample periods during the test period. 
     The host program  160  defaults to a recommended flow rate, an overall test period for the accuracy test, and a recommended weight sample period within the test period. The host program  160  selects these based upon the particular specifications for accuracy of the IV pump  20  undergoing testing, as set forth in the test matrix  162  generated for the pump  20 . The selected test and sample periods take into account the flow conditions encountered during normal use of the particular pump. 
     For example, one pump (like a Pharmacia Deltec™ Model CADD-5800) operates at relatively a low flow rate of 20 mL/hr in normal use. Another pump (like a Pharmacia Deltec™ Model CADD-5101HF) operates at a relatively high flow rate of 299 mL/hr in normal use. The host program  160  requires longer test and sampling periods for lower flow rates, to thereby preserve a high degree of accuracy (preferably less than 1%) during testing. Therefore, the preselected test and sample periods for the lower flow rate pump are longer than the selected test and sample periods for the higher flow rate pump. Likewise, the selected test and sample periods for the lower flow rate pump are longer than the selected test and sample periods for the higher flow rate pump. 
     Still, the host program  160  preferably allows, within a reasonably prudent range of acceptable test and sample periods, the operator to change the selected test and/or sample period in his/her discretion. 
     The host program  160  also defaults to the specific gravity of water as the liquid to be used for the flow rate tests. The host program  160  also allows the operator to select another liquid (for example, a TPN solution) and alter the specific gravity according. 
     Under the direction of the host program  160 , the host CPU  24  processes the changes in the digital weight signals during successive sample periods to gravimetrically calculate the flow rates periodically throughout the test period. 
     In the illustrated and preferred embodiment (see FIG.  18 ), the host CPU  24  uses a “data burst” technique to filter multiple digital weight samples over each sample period. More particularly, the host CPU  24  takes a prescribed number (n) of digital weight samples (a “data burst” of n data samples, or SAMPLE(J), where J=1 to n) during each sample period. Preferably, the bursts are clustered at the end of the sample period. For example, given a sample period of about 1 minute, the data burst of five samples is begun at about the 58th second of the period. After the five data samples within the burst are taken (at about 0.5 seconds per data sample), a new sample period is initiated. 
     The host CPU  24  then calculates an average (BURST AVE ) and a standard deviation (BURST STD ) of the n samples in the burst. The CPU  24  then compares each of the n samples (SAMPLE (J), for J=1 to n) and rejects a SAMPLE(J) when the absolute value of BURST AVE −SAMPLE(J)&gt;SET, where SET=k * BURST STD , k being a preselected value. In the preferred embodiment, k is 1.5. 
     Upon rejecting one or more SAMPLE(J) within the burst based upon this criteria, the CPU  24  again calculates BURST AVE  and BURST STD  for the remaining samples within the burst (J now equalling 1 to the value of n minus the number of samples rejected). The CPU  24  again reviews the remaining samples to determine whether each meet the selected standard deviation variance. The CPU  24  continues to reject samples that fall outside the standard deviation variance and recalculate a new BURST AVE  and BURST STD  for the remainder of the samples, until all samples remaining the burst meet the standard deviation variance criteria. BURST AVE  after such processing is then used as the weight for calculating flow rate at the end of each sample periods. 
     The CPU  24  compares the actual flow rate data derived during the test period to prescribed flow rate criteria. The prescribed flow rate criteria are selected based upon the flow rate accuracy specified by the manufacturer for the particular pump undergoing testing, which is set forth in the test matrix  162  (see FIG.  14 B). Based upon this comparison, the CPU  24  determines whether or not the processed actual flow rate data meets the criteria established by the manufacturer. 
     In the preferred embodiment (see FIG.  19 ), the CPU  24  makes this determination based upon the overall accuracy of the IV pump during the test period. More particularly, to meet the established criteria, the CPU  24  requires that a prescribed number of flow rates sampled at consecutive sample periods during the test period fall within the manufacture&#39;s specified range of accuracy during the test period. The host program selects the prescribed number of consecutive samples based upon the set flow rate during the test period. 
     Still, the host program  160  allows, within a window of acceptable values, the operator to change the number of flow rate samples required in his/her discretion. 
     If the specified number of consecutive flow rates sampled during the test period fall within the range of flow rates specified in the test matrix  162 , the host program  160  registers a PASS result. Otherwise, the host program  160  registers a FAIL result. 
     In a preferred implementation, the host program graphically displays the flow rate accuracy test in real time as the test proceeds. FIG. 25 shows a representative graphical display. The graphical display shows time on the horizontal axis and percent above and below the accuracy flow rate set by the test matrix on the vertical axis. The manufacturer&#39;s specified range of accuracy (in percentage), as also set by the test matrix, is bounded by horizontal lines extending above and below the zero percent axis. In FIG. 25, the specified range of accuracy is plus/minus 5%. 
     The graphical display in FIG. 25 plots the interval average as well as the overall average as a function of time. FIG. 25 shows an overall average of +1.3% for the test period. The overall average is also continuously graphically displayed as a floating icon on the right hand side of the display throughout the test period. In FIG. 25, the pump achieved a PASS result. 
     (c) Occlusion Pressure Tests 
     The host program  160  carries out the occlusion pressure tests by prompting the operator to simulate an upstream occlusion (between the solution bag  170  and the IV pump  20 ) and by operating the test station  12  to simulate a downstream occlusion (between the pump  20  and the patient). The IV pump  20  must pass both upstream and downstream occlusion tests to pass the overall occlusion pressure tests. 
     (i) Upstream Occlusion Test 
     In carrying out the upstream occlusion tests (see FIGS.  16 A and  20 A), the host program  160  prompts the operator to clamp the upstream tubing  168  close while the IV pump is operating, thereby simulating an upstream occlusion (see FIG. 16A) The operator is prompted to notify the host program  160 , either by using the mouse  30  or the keyboard  28 , when the occlusion alarm of the pump  20  sounds. 
     The host program  160  measures the time interval between the simulated upstream occlusion T OCCLUDE  and the time T ALARM  at which the operator indicates the alarm has sounded (see FIG.  20 A). The host program  160  compares the measured time interval T ALARM −T OCCLUDE  to a prescribed time period T SET  that the host program  160  sets according to the manufacturer&#39;s specification for the IV pump. If the measured time period falls within the specified time period, the host program  160  registers a PASS result. Otherwise, the host program  160  registers a FAIL result. 
     (ii) Downstream Occlusion Test 
     In carrying out the downstream occlusion tests (see FIGS.  16 B and  20 B), the host program  160  prompts the user to operate the pump  20  at a specified flow rate to convey liquid to the collection bottle  48  in the wet chamber. The host program directs the test station microprocessor  132  to activate the first solenoid  54 . In this condition (see FIG.  16 B), liquid conveyed by the IV pump  20  cannot flow beyond the inlet valve station  50 , thereby simulating a downstream occlusion. The operator is prompted to notify the host processing station, either by using the mouse  30  or the keyboard  28 , when the occlusion alarm of the pump  20  sounds. 
     During the simulated downstream occlusion, liquid pressure builds in the second branch  60  of the inlet valve station  50 , as FIG. 16B shows. The pressure transducer  70  senses the increasing pressure. The test station microprocessor  132  converts the analog pressure signals received from the pressure transducer  70  to digital signals, which are sent to the host CPU  24 . 
     During the downstream occlusion, the host program  160  continuously monitors the pressure sensed by the pressure transducer  70  P SENSE . The host program  160  continuously compares the measured pressure PSENSE to a prescribed maximum pressure P MAXSET  that the host program  160  sets. P MAXSET  can be set by the host program  160  according to the manufacturer&#39;s specification for the given IV pump, or it can be set by the host program  160  at a generic value (e.g. 36 PSIG) applicable to IV pumps in general. If any pressure reading P SENSE  sensed during the test interval set by the host program  160  exceeds the maximum set for the pump P MAXSET , the host program  160  immediately registers a FAIL result. 
     If the measured sensed pressure P SENSE  does not exceed the specified minimum pressure P MAXSET  during the test interval, the host program  160  prompts the operator to indicate whether the pump occlusion alarm sounded during the test interval. If the operator provides input that the occlusion pump alarm did sound during the test period, the host program  160  registers a PASS result. However, if the operator occlusion pump alarm does not go off during the test period, the host program  160  registeres a FAIL result, even when the measured sensed pressure P SENSE  does not exceed the specified minimum pressure P MAXSET  during the test interval. 
     In a preferred implementation, the host program  160  consolidates the time and pressure sensing aspects of the test in an intuitive graphical display, which is presented in real time as the tests proceed. 
     FIG. 26A shows a representative graphical display during the upstream occlusion test. The display depicts a digital timer that begins at T SET  and counts down to zero. The operator clicks the PASS button as soon as the occlusion alarm sounds. If the PASS button is clicked before the time runs out on the timer, the pump receives a PASS result for the downstream occlusion test. FIG. 26A shows a count-down timer originally set at 5:00 minutes. FIG. 26A shows that the occlusion alarm sounded within six seconds, the digital timer having counted down in real time from 5:00 minutes (T SET ) to 4:54 minutes. 
     FIG. 26B shows a companion display for the downstream occlusion test. The companion display depicts a pressure gauge showing the instantaneous, sensed pressure during the test interval. FIG. 26B shows this sensed pressure to be 30 PSIG, less than the P SET  of 36 PSIG. The display also shows that the occlusion alarm sounded during the test interval, as the operator has checked the Pass button next to the gauge. 
     FIGS.  26 A/B show the pump to have passed both the upstream and downstream segments of occlusion pressure test. 
     If the host program  160  registers a PASS result for both the upstream and the downstream occlusion tests, the host program  160  registers an overall PASS result for the occlusion pressure tests. If the host program registers a FAIL result for either the upstream occlusion test or the downstream occlusion test, the host program  160  registers an overall FAIL result for the occlusion pressure tests. 
     Upon completing the occlusion pressure tests, the host program  160  directs the test station microprocessor  132  to deactivate the first solenoid  54  to relieve the simulated downstream occlusion. 
     (d) Test Station Drain 
     At some point after completing all liquid conveyance tests using the test station  14 , the host program  160  directs the operator to turn off and disconnect the IV pump  20  from the test station  14 . The host program  160  directs the test station microprocessor  132  to activate the second solenoid  56 . In this condition (see FIG.  17 ), liquid collected in the bottle  48  drains through the drain tube  82  into the receptacle  172  provided. 
     In a preferred embodiment, the host program  160  uses the load cell  44  to monitor the total volume of liquid entering the bottle  48  during the liquid conveyance tests. During subsequent drainage of the bottle, the host program  160  uses the load cell  160  to monitor the volume of liquid that drains from the bottle  48 . The host program  160  compares the volume of liquid that entered the bottle  48  during the tests with the volume of liquid drained from the bottle  48  after the tests. If the two volumes do not compare, the host program  160  generates an alert, prompting the operator to open the access door  112  to the wet chamber  40  and check the bottle  48  for residual liquid. 
     Furthermore, the host program  160  can sense when the bottle  48  fills during a given liquid conveyance test by comparing the total volume of liquid entering the bottle  48  to a pre-established value corresponding to the safe liquid capacity of the bottle  48 . In this situation, the host program  160  suspends the ongoing test and directs the test station microprocessor  132  to activate the second solenoid  56  to drain the bottle  48 . Following drainage, the host program  160  resumes the suspended liquid conveyance test. 
     (4) Electrical Safety Tests 
     The host program  160  carries out the electrical safety tests, if required by the test matrix  162  (see FIG.  11 ), by directing the test station microprocessor  132  to operate the relays on the first circuit board  122  in the dry chamber  42 . The test station microprocessor  132  registers a series of measurements that test ground continuity, leakage current, and other electrical safety functions recommended or required by UL and/or AAMI. 
     The test station microprocessor  132  transfers these electrical measurements to the host CPU  24 . The host program  160  compares these measured values to prescribed values set by the host program  160  based upon UL or AAMI standards. 
     The particular electrical aspects of the IV pump  20  identified for measurement during the electrical safety tests can vary according to the particular specifications of the pump  20 . In the preferred embodiment, the aspects that the host program  160  includes during the electrical safety tests include: 
     1. Internal Leakage; AC Off; Reverse Polarity; No Ground. 
     2. Internal Leakage; AC Off; Reverse Polarity; With Ground. 
     3. Internal Leakage; AC On; Reverse Polarity; No Ground. 
     4. Internal Leakage; AC On; Reverse Polarity; With Ground. 
     5. Internal Leakage; AC Off; Normal Polarity; No Ground. 
     6. Internal Leakage; AC Off; Normal Polarity; With Ground. 
     7. Internal Leakage; AC On; Normal Polarity; No Ground. 
     8. Internal Leakage; AC On; Normal Polarity; With Ground. 
     9. External Leakage; AC Off; Reverse Polarity; No Ground. 
     10. External Leakage; AC Off; Reverse Polarity; With Ground. 
     11. External Leakage; AC On; Reverse Polarity; No Ground. 
     12. External Leakage; AC On; Reverse Polarity; With Ground. 
     13. External Leakage; AC Off; Normal Polarity; No Ground. 
     14. External Leakage; AC Off; Normal Polarity; With Ground. 
     15. External Leakage; AC On; Normal Polarity; No Ground. 
     16. External Leakage; AC On; Normal Polarity; With Ground. 
     17. Ground Wire Resistance. 
     If a given measured electrical value meets the specified value, the host program  160  registers a PASS result for that measured electrical value. Otherwise, the host program  160  registers a FAIL result. 
     If the host program  160  registers a PASS result for all measured electrical values, the host program  160  registers an overall PASS result for the electrical safety tests. If the host program  160  registers a FAIL result for any one measured electrical value, the host program  160  registers an overall FAIL result for the electrical safety tests. 
     The particular construction, arrangement, and operation of electrical components  68  on the first circuit board  122  to carry out the electrical safety tests can vary. FIGS. 28A and 28B shows a preferred embodiment. 
     FIG. 28A shows the relay control signals generated by the test station microprocessor  132  are communicated as a digital, eight bit binary code. The code is first channeled in groups of two through four optical isolation devices  204 ( 1 );  204 ( 2 );  204 ( 3 ); and  204 ( 4 ). The devices  204 ( 1 )-( 4 ) each comprises a type HCPL2731 optical isolation device. Each device converts the received bits of digital code into light signals emitted by associated LED sources  206 , which are received by sensors  208 . The details of this are shown only for device  204 ( 1 ), although all devices  204 ( 1 ) to ( 4 ) are identically constructed. 
     The light signals are decoded by two decoders  208 ( 1 ) and ( 2 ), which are type 74LS138 and 74LS158 decoders, respectively. The decoded signals are then transmitted to a type UDN2395A relay driver  210 . Based upon the (now processed and decoded) eight bit code it receives, the driver  210  activates one or more selected relays, which are shown in FIG.  28 B. 
     There are nine relays on the first circuit board  122 , identified in FIG. 28B as RY 1  to RY 9 . The relays RY 1  to RY 9  are each mechanically linked to one or more switch elements, numbering fifteen and designated S 1  to S 15  in FIG.  28 B. The linkage between a relay and a switch or switches is shown by dotted lines in FIG.  28 B. 
     As FIG. 28B shows: 
     Relay RY 1  is linked to switch S 11 . 
     Relay RY 2  is linked to switch S 12 . 
     Relay RY 3  is linked in tandem to switches S 5  and S 6 . 
     Relay RY 4  is linked in tandem to switches S 13  and S 14 . 
     Relay RY 5  is linked in tandem to switches S 9  and S 10 . 
     Relay RY 6  is linked to switch S 15 . 
     Relay RY 7  is linked in tandem to switches S 3  and S 4 . 
     Relay RY 8  is linked in tandem to switches S 1  and S 2 . 
     Relay RY 9  is linked in tandem to switches S 7  and S 8 . 
     Voltage from the power source PS 1  enters the switched circuit shown in FIG.  28 B through terminal TB 1 , pin  1  (AC Hot); pin  2  (AC Ground); and pin  3  (AC Low), which are controlled by switches S 13  (AC Hot) and S 14  (AC Low). The three prong pump plug outlet  144  (on the front panel  66  of the test station  12 ) communicates with the switched circuit through terminal TB 1 , pins  4 ,  5 , and  6 , which are controlled by S 6 ; S 5 ; and S 11 , respectively. Switch S 10  is common to all pins  1  to  6  on terminal TB 1 . The external ground probe  142  of the test station is connected at terminal J 2 , pin  2 , which is controlled by switch S 9 . The remaining switches further direct current flow to carry out the various electrical tests desired. 
     As configured in FIG. 28B, relay RY 1  controls the open grid. Relay RY 2  controls power on/off. Relay RY 3  controls reverse polarity. Relay RY 4  controls power on activate. Switch RY 5  controls the selection between resistance and leakage testing. Switch RY 6  control internal (test station) and external (pump) electrical testing. Switch RY 7  controls the leakage signal. Switch RY 8  controls the ground resistance signal. Switch RY 9  controls the line voltage signal. 
     The relay driver  210  provides signals to activate the relays RY 1  to RY 9  alone or in groups to conduct the various electrical safety tests as follows: 
     
       
         
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
             
           
               
                   
               
               
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     Key to Tests by Test Number 
     1. Ground Resistance 
     2. External Leakage, AC on, Normal Polarity, Normal Ground. 
     3. External Leakage, AC on, Normal Polarity, Open Ground. 
     4. External Leakage, AC off, Normal Polarity, Normal Ground. 
     5. External Leakage, AC off, Normal Polarity, Open Ground. 
     6. External Leakage, AC on, Reverse Polarity, Normal Ground. 
     7. External Leakage, AC on, Reverse Polarity, Open Ground. 
     8. External Leakage, AC off, Reverse Polarity, Normal Ground. 
     9. External Leakage, AC off, Reverse Polarity, Open Ground. 
     10. Internal Leakage, AC on, Normal Polarity, Normal Ground. 
     11. Internal Leakage, AC on, Normal Polarity, Open Ground. 
     12. Internal Leakage, AC off, Normal Polarity, Normal Ground. 
     13. Internal Leakage, AC off, Normal Polarity, Open Ground. 
     14. Internal Leakage, AC on, Reverse Polarity, Normal Ground. 
     15. Internal Leakage, AC on, Reverse Polarity, Open Ground. 
     16. Internal Leakage, AC off, Reverse Polarity, Normal Ground. 
     17. Internal Leakage, AC off, Reverse Polarity, Open Ground. 
     18. Flow Rate Testing, AC to outlet  144  on. 
     19. Pressure Testing, AC to outlet  144  on. 
     20. AC line check, AC to outlet  144  off. 
     21. Ground to Neutral Line Check. 
     In the above table, a given relay with an open box (without an “X”) indicates that the switch or switches associated with the relay are in the position shown in FIG. 28B. A given relay with a filled box (with an “X”) indicates that the relay is activated and the switch or switches associated with the relay occupy the alternative position shown in FIG.  28 B. 
     (5) The Score Card 
     In a preferred implementation, the host program  160  provides a graphical scorecard (see FIG. 27) presenting the PASS/FAIL results for each category of test and the overall PASS/FAIL result. In FIG. 27, a check mark indicates a PASS result, while an “IX” indicates a FAIL result. By clicking on a given test category, the host program displays the detailed test information for that category. 
     By clicking the Print button, the host program  160  generates either Pump Certification Report (see FIG. 21) (if the pump received an overall PASS result) or a Pump Failure Report (see FIG. 22) (if the pump received an overall FAIL result, as the pump in FIG. 27 did). The host program  160  also generates and prints the Detailed Test Result Report (FIGS.  23 A/B). 
     C. Test Station Calibration 
     As FIG. 11B shows, the host program  160  periodically prompts the operator to calibrate certain liquid measurement and electrical components of the test station  14 . The period of time between these calibrations can vary. It is presently believed that host-prompted calibration of the test station  14  should occur every day of use. 
     The components in the test station  14  selected for periodic calibration can vary. In the illustrated and preferred embodiment, the load cell  44 , the ground probe  146 , and electrical components of the test station  14  are periodically recalibrated at the prompting of the host program  160 . 
     (1) Load Cell Recalibration 
     To carry out a recalibration of the load cell  44 , the host program  160  prompts the operator to open the access door  112  to the wet chamber  40 . The host program  160  directs the test station microprocessor  132  to transmit the load cell reading with the bottle  48  empty. 
     The host program  160  then prompts the operator to remove weight W1 from the bracket  118  on the door and place it on the empty bottle  48 . In the illustrated and preferred embodiment, this weight W1 is 100 gr. The host program  160  directs the test station microprocessor  132  to transmit the load cell reading with the 100 gr weight present on the empty bottle  48 . 
     The host program  160  then prompts the operator to place the other weight W2 from the door bracket  118  and place it on the first weight W1 on empty bottle  48 . In the illustrated and preferred embodiment, this second weight W2 is 25 gr. The host program  160  directs the test station microprocessor  132  to transmit the load cell reading with the 125 gr weight present on the empty bottle  48 . 
     The host program  160  linearly interpolates the load cell readings for the three weight values—zero, or tare weight, for the empty bottle  48 ; the 100 gr weight on the bottle  48 ; and the 125 gr weight on the bottle  48 . The host program  160  uses the zero (tare) weight and 100 gr readings, along with the assumption of a linear output among all three readings, to mathematically adjust the load cell readings during subsequent tests. 
     The host program  160  preferably establishes a range for calibrated weight readings. Should the calibration weight readings fall outside the established range, the host program  160  prompts the operator that the load cell  44  requires servicing. 
     Upon completing load cell recalibration, the host program  160  prompts the operator to return the weights W1 and W2 to the door bracket  118 . 
     Before conducting any subsequent flow rate accuracy tests (described above), the host program  160  queries the test station microprocessor  132  to sense the tare weight to ensure that the collection bottle is in place on the load cell  44  and the calibration weights W1 and W2 have been removed. 
     (2) Electrical Safety Tests 
     With the access door  112  to the wet chamber  40  open, the host program  160  prompts the operator to connect the ground continuity probe  146  to a selected one of the resistance studs S 1  mounted in the wet chamber  40  on the dividing plate  38 . One stud S 1  has a known resistance of zero ohms, while the other stud S 2  has a known resistance of a different value (e.g., 1 ohm). 
     The host program  160  directs the test station microprocessor  132  to perform a ground resistance test using the known resistance of the stud S 1  to which the ground probe  146  is attached. The host program  160  directs the test station microprocessor  132  to perform a ground resistance test. The microprocessor  132  should output a ground resistance value of zero ohm. 
     The host program  160  then prompts the operator to connect the ground probe  146  to the other stud S 2 . Again, the host program  160  directs the test station microprocessor  132  to perform a ground resistance test. The microprocessor  132  should output a ground resistance value of one ohm. 
     If either output does not match the expected resistance value, the host CPU  32  alerts the operator that calibration of the test station by a service technician is required. 
     When the test station calibration tests are successfully completed, the host program  160  prompts the operator to disconnect the ground continuity probe  146  from the test studs S 1  and S 2  and to close the access door  112  to the wet chamber  40 . 
     III. The Data Reporting Station 
     The host CPU  24  processes the acquired raw data and the PASS/FAIL results for each IV pump tested. The CPU  24  stores this information in the log file database  164 . The host CPU  24  also transmits this processed data to the data reporting station  16  for printing the in form of reports. 
     A. The Pump Pass/Failure Report 
     If the IV pump receives a PASS result in all applicable visual inspection tests, flow rate accuracy tests, occlusion pressure tests, and electrical safety tests, the host CPU  24  generates and sends to the data reporting station from printing a Certification Report for the IV pump in the form shown in FIG.  21 . As FIG. 21 shows, the Certification Report includes a preprinted label that can be attached to the IV pump indicating its certification and that date of certification. 
     If the IV pump receives a FAIL result in some or all applicable visual inspection tests, flow rate accuracy tests, occlusion pressure tests, and electrical safety tests, the host CPU  24  generates and sends to the data reporting station a Pump Failure Report for the IV pump in the form shown in FIG.  22 . 
     B. The Detailed Test Result Report 
     Both the Certification Report and the Pump Failure Report are accompanied by the Detailed Test Results Report in the form shown in FIGS.  23 ( a ) to ( d ). The Detailed Test Results Report lists for each applicable visual inspection tests, flow rate accuracy tests, occlusion pressure tests, and electrical safety tests, the PASS/FAIL results, with the associated raw data supporting the result. when appropriate. 
     For an IV pump receiving the Pump Failure Report, a review of the associated Detailed Test Results Report pinpoints the areas where performance failed to meet established criteria. It therefore simplifies subsequent trouble shooting and repair by an qualified service representative. 
     C. Consolidated Database Reports 
     The log file database  164  is a relational database. It offers the operator the flexibility of generating a diverse number of reports, presenting the data in the database  164  in different ways. 
     By way of example (see FIG.  11 C), the host program  162  can generate various types of certification reports, in letter, listing, summary, or detailed form. Also by way of example, the host program  162  can generate various types of database reports, such as all or any selected part of the pump log files, e.g., individually, by manufacturer, or by alpha-numeric designation. 
     Drawing upon the host usage database  166  in the same manner, the host program  160  can generate diverse types of accounting reports relating to the use and performance of the system  10 . 
     Various features of the invention are set forth in the following claims.