Patent Publication Number: US-2021170156-A1

Title: System for identifying the presence and correctness of a medical device accessory

Description:
RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/124,446, filed on Sep. 7, 2018, pending, which is a continuation of U.S. patent application Ser. No. 15/819,131, filed on Nov. 21, 2017, now U.S. Pat. No. 10,105,528, which is a continuation of U.S. patent application Ser. No. 15/018,069, filed on Feb. 8, 2016, now U.S. Pat. No. 9,849,275, which is a continuation of U.S. patent application Ser. No. 13/683,572, filed on Nov. 21, 2012, now U.S. Pat. No. 9,283,334, which claims the benefit of U.S. Provisional Application No. 61/563,119, filed on Nov. 23, 2011, expired, all of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to medical device accessories, and in particular, a system for identifying the presence and correctness of a medical device accessory. 
     BACKGROUND 
     In many areas of medical treatment, the transportation of gases or liquids in various treatments is required. Such treatments, for example, include respiratory, surgical, arthroscopic, laparoscopic, urologic, and even subcutaneous applications (e.g., injections, or sub-dermal insufflation). Because of the complexity of medical treatments and the large number of different but occasionally related procedures, there is a high possibility of attaching or hooking up the wrong medical device accessory to a particular medical device for a particular medical treatment. In the case of tubing sets, for example, the conduits can be metal, rigid or flexible plastic, tubes, or even just a needle itself. The tubing sets may also have characteristics specific to a particular medical treatment, such as conduit diameter, length, pressure ratings, temperature ratings, fluid flow ratings, etc. There is often a need to match the proper conduit to the proper medical device (e.g., an insufflator, a pump, etc.) to insure the proper performance of the medical device, or to insure the medical device performs in certain ways. 
     Furthermore, within the medical field, hospitals, surgi-centers, and doctors&#39; offices often re-use tubing sets for the transportation of gases or liquids which were intended for a single use. This practice has safety, health (e.g., infection), and equipment reliability and performance issues. Practitioners will often substitute tubing sets for manufacturer approved and tested tubing sets without an understanding of the resulting consequences. For example, in laparoscopic insufflation, instances have occurred where an insufflator has become contaminated due to the use of a sub-standard tubing set, or the re-use of a tubing set. In such instances, the potential consequences may also include the insufflator measurement system becoming compromised by a restrictive tubing set, or other degradation of the performance of the insufflator. 
     To address these and other issues, a system for identifying the presence and correctness of a medical device accessory is described herein. 
     BRIEF SUMMARY 
     In one aspect, a medical device accessory includes an interface configured to connect the medical device accessory with a medical device for administration of a medical treatment using the medical device and the medical device accessory. A plurality of electrical contacts are proximate the interface. The electrical contacts include a lead electrical contact adapted to receive a voltage from a power source associated with the medical device and one or more identifying electrical contacts. At least one conductor provides an electrical connection between the lead electrical contact and the one or more identifying electrical contacts. An arrangement of the one or more identifying electrical contacts connected to the lead electrical contact identifies a characteristic of the medical device accessory. 
     In another aspect, a conductor of the at least one conductors is configured for alignment with a severing element associated with the medical device and is mechanically severable upon disconnection of the medical device accessory with the medical device. The characteristic of the medical device accessory that is identified, after disconnection of the medical device accessory with the medical device, is a prior use of the medical device accessory. 
     In another aspect, the medical device accessory is characterized by an absence of an active component electrically connected to the lead electrical contact. The active component may be a resistor, a fuse, a memory chip, a capacitor, an optical sensor, or a radio-frequency identification component. 
     In yet another aspect, the characteristic of the medical device accessory that is identified may be an operating parameter of the medical device for operation with the medical device accessory. Alternatively, the characteristic may be a proper connection of the medical device accessory with the medical device. In another alternative, the characteristic may be an identity of the medical device accessory. 
     In another aspect, the medical device accessory may be a connector configured to connect the medical device with another medical device accessory. 
     In another aspect, the medical device accessory may include a conduit having a lumen for transporting a fluid. 
     In yet another aspect, the arrangement of the one or more identifying electrical contacts connected to the lead electrical contact may be adapted to provide the voltage to a controller associated with the medical device. 
     In another aspect, a medical device accessory includes an interface configured to connect the medical device accessory with a medical device for administration of a medical treatment using the medical device and the medical device accessory. The medical device accessory also includes a lead electrical contact adapted to receive a voltage from a power source associated with the medical device, an identifying electrical contact, and a conductor providing an electrical connection between the lead electrical contact and the identifying electrical contacts. The conductor is configured for alignment with a severing element associated with the medical device and is mechanically severable upon disconnection of the medical device accessory with the medical device to provide an indication of prior use of the medical device accessory. 
     In a further aspect, a medical device accessory includes an interface configured to connect the medical device accessory with a medical device for administration of a medical treatment using the medical device and the medical device accessory. A plurality of tabs proximate the interface are configured to engage a plurality of corresponding switching elements associated with the medical device upon connection of the medical device accessory with the medical device. An arrangement of the plurality of tabs identifies a characteristic of the medical device accessory. 
     In yet another aspect, one or more of the plurality of tabs are configured to move one or more of the plurality of corresponding switching elements from a first position to a second position upon connection of the medical device accessory with the medical device. 
     In another aspect, a tab of the plurality of tabs is breakable upon engagement with one of the plurality of corresponding switching elements. The characteristic of the medical device accessory that may be identified, after disconnection of the medical device accessory with the medical device, is a prior use of the medical device accessory. 
     In a further aspect, a medical device accessory includes an interface configured to connect the medical device accessory with a medical device for administration of a medical treatment using the medical device and the medical device accessory. A tab proximate the interface is configured to engage and move a corresponding switching element associated with the medical device from a first position to a second position upon connection of the medical device accessory with the medical device. The tab is breakable upon engagement with the switching element to provide an indication of prior use of the medical device accessory. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front perspective view of a medical device accessory in the form of a tubing set; 
         FIG. 2  is a cross-sectional side view of the medical device accessory of  FIG. 1 ; 
         FIG. 3  is a top view of a printed circuit board housed in the medical device accessory of  FIG. 1 ; 
         FIG. 4  is a partial cross-sectional view of a port on a medical device adapted for mechanically severing a conductor printed on the circuit board of the medical device accessory upon disconnection of the medical device accessory with the medical device; 
         FIGS. 5A-C  are exemplary illustrations of electrical contacts and conductors printed on a circuit board; 
         FIG. 6  is a diagram illustrating a circuit formed by a medical device accessory connected with a medical device; 
         FIG. 7  is a chart showing the logic states of the switches in the circuit of  FIG. 6 ; 
         FIG. 8  is a flow chart illustrating the reading process performed by a controller in the circuit of  FIG. 6 ; 
         FIG. 9  is a perspective view of an alternative embodiment of a medical device accessory; 
         FIG. 10  is a perspective view of another embodiment of a medical device accessory; and, 
         FIG. 11  is a perspective view of an identification device for use with the medical device accessory of  FIG. 10 . 
     
    
    
     DETAILED DESCRIPTION 
     Described herein are systems for identifying the presence and correctness of a medical device accessory. Although the following description refers to specific embodiments where the medical device accessory is a medical tubing set, those skilled in the art will appreciate that the disclosed concepts and principles may be applied to any medical device accessory, and may be embodied in a separate accessory adapted to connect a medical device to another medical device accessory, i.e., as an intermediate connector. 
     Notably, in one embodiment, the medical device accessory utilizes a voltage or a current, without using any active elements (i.e., a component that in some way changes its state or function, or communicates actively with a device with or without physical contact), and yet provides a way to communicate presence and characteristics of the medical device accessory. One advantage to this approach is the omission of expensive active components such as, for example, resistors, fuses, memory chips, capacitors, optical sensors, radio-frequency identification components, readers/transponders, bar codes, etc. Rather, as explained below, the system can be implemented using inexpensive voltage or current measurement circuitry. This system has in comparison to the prior art, ease of manufacture, very low cost, multiple configurations, no need for complex methods to identify the medical device accessory, an inexpensive means for disabling use of the accessory, basic electronics for measuring voltage or current, and ease of programming using basic binary coding concepts. 
     Referring first to  FIGS. 1 and 2 , a front perspective view and a cross-sectional side view of a medical device accessory in the form of a tubing set  100  is shown. The tubing set  100  is comprised of a connector  102  disposed at an end of a tube  104 . As shown in  FIG. 2 , the connector  102  may include a female end  106  for receiving the tube  104 , a conduit  108  extending through the connector  102 , and a male end  110  adapted to engage a suitable corresponding connection on a medical device, for example, a tubing nipple or a luer. Although the connector  102  and the tube  104  are shown as separate components, it is envisioned that the connector  102  may be integrally formed with the medical device accessory. Alternative interfaces for tubing sets could include, for example, quick disconnect, friction fit, luer type, barbed connections, bayonet fittings, etc. It should be appreciated that any suitable interface for connecting a medical device accessory with a medical device may be utilized without departing from the concepts and principles described herein. 
     The connector  102  further comprises an electrical housing  112 . Preferably, the electrical housing  112  is proximate to the interface, i.e. the male end  110  of the connector  102 , such that the connection of the medical device accessory with the medical device is unobtrusive. As shown in FIG.  3 , an exemplary circuit board  114  is shaped and sized to fit within the electrical housing  112 . The circuit board  114  comprises a plurality of electrical contacts designed to engage corresponding electrical contacts on a medical device (not shown). The circuit board  114  further comprises one or more electrical conductors providing an electrical connection between the electrical contacts. As explained below, one or more of the electrical conductors may be severable upon disconnection of the medical device accessory with the medical device, such as for example, by skiving or cutting. 
     The circuit board  114  shown in  FIG. 3  includes five electrical contacts  116 ,  118 ,  120 ,  122  and  124 , and two conductors  126  and  128 . The conductor  126  provides an electrical connection between the electrical contacts  116  and  118 , whereas the conductor  128  provides an electrical connection between the electrical contacts  122  and  124 . It is envisioned that the circuit board could include as few as two electrical contacts, or significantly more. Similarly, it is envisioned that any number of electrical conductors could provide an electrical connection between any number of the electrical contacts. Furthermore, it is envisioned that the circuit board  114  could be double-sided, i.e., electrical contacts and conductors printed on both the top and bottom of the circuit board  114 , thereby increasing the amount of information provided on a single circuit board. 
     The tubing set  100  is intended to be used and connected with a medical device adapted to receive the male end  100  of the connector  102 , as well as the circuit board  114  and the electrical contacts  116 ,  118 ,  120 ,  122 , and  124 . For example, the medical device may comprise a plurality of corresponding electrical contacts or pins adapted to create an electrical connection with one or more of the electrical contacts  116 ,  118 ,  120 ,  122 , and  124 . Furthermore, as explained below in greater detail, the medical device may include a controller and simple circuitry connected to the contacts or pins for reading and determining the presence and correctness of a medical device accessory. 
     In one embodiment, the system can determine the presence and/or whether the medical device accessory has previously been used. Based on the determination, the system may, for example, provide an indication that the medical device accessory is not present, or that the medical device accessory has previously been used. In this embodiment, the circuit board  114  includes only two electrical contacts and a conductor providing an electrical connection therebetween, for example, electrical contacts  116 ,  118  and conductor  126  of the circuit board  114  shown in  FIG. 3 . When a medical device accessory having this configuration is connected with a medical device adapted to receive the medical device accessory, if a voltage is supplied by the medical device at an electrical contact or pin engaged with or corresponding to the electrical contact  116 , the medical device can read the voltage at a contact or pin engaged with the electrical contact  118 . By periodically providing a voltage at electrical contact  116  and checking for the same voltage at electrical contact  118 , the system can determine the presence of a medical device accessory. In other words, when the medical device accessory is connected with the medical device, the circuit formed between electrical contacts  116  and  118  is closed. In this way, the system can determine the presence of a medical device accessory. 
     In this embodiment, the system may also be able to determine if the medical device accessory has previously been used. For example, as shown in  FIG. 4 , a partial cross-sectional view of a port  130  on a medical device is adapted for mechanically severing a conductor printed on the circuit board of the medical device accessory upon disconnection from the medical device. The port  130  is disposed on the medical device proximate the interface for connecting the medical device accessory to the medical device, and is adapted to receive, for example, the circuit board  114 , the electrical contact  116 ,  118 , and the conductor  126 . The port  130  may also house the electrical contacts or pins (not shown) associated with the medical device and which are adapted to engage the electrical contacts  116 ,  118  on the circuit board  114 . The port  130  further comprises a skiving blade  132  positioned and configured to mechanically sever the conductor  126  upon withdrawal of the circuit board  114  from the port  130 . 
     As shown in  FIG. 4 , the skiving blade  132  comprises a curved front face  134  and a sharp rear edge  136 . Accordingly, the skiving blade  132  permits the medical circuit board  114  and the conductor  126  to slide unsevered past the curved front face  134  of the skiving blade  132  upon insertion of the circuit board  114  into the port  130 , i.e., connection of the medical device accessory with the medical device, whereas the sharp rear face  136  of the skiving blade  132  mechanically severs the conductor  126  upon withdrawal of the circuit board  114 , i.e., disconnection of the medical device accessory with the medical device. It should be appreciated that the conductor could be mechanically severed by any other suitable means, for example, by scribing or cutting. Alternatively, it is envisioned that a small laser (not shown) could be provided within the port  130  for vaporizing a portion of a conductor and breaking the electrical connection between electrical contacts. 
     In this way the medical device is able to supply a voltage at an electrical contact or pin engaged with or corresponding to the electrical contact  116 , and read the voltage at a contact or pin engaged with the electrical contact  118  to determine if the circuit is closed. If the corresponding medical device is adapted to sever the conductor  126  upon disconnection of the medical device accessory with the medical device, an open circuit indicates that the medical device accessory has previously been used. Alternatively, a closed circuit indicates that a medical device accessory is present, and that the medical device accessory has not previously been used. 
     In a second embodiment, the system is able to determine the presence and/or whether the medical device accessory has previously been used, as well as other characteristics of the medical device accessory. By increasing the number of electrical contacts and using conductor patterns (i.e., reading the arrangement of electrical contacts electrically connected to the electrical contact receiving a voltage from the medical device), the system can identify additional characteristics of the medical device accessory. 
     In an embodiment where the circuit board  114  includes at least four electrical contacts and two conductors, e.g., electrical contacts  116 ,  118 ,  122 ,  124  and conductors  126  and  128 , a code (similar to a binary code) can be used to identify a code associated with the medical device accessory. For example, after the medical device supplies a voltage, an electrical connection, or a closed circuit, between electrical contacts  116  and  118  could represent a binary “1”, and an open circuit between electrical contacts  122  and  124  could represent a binary “0”. Combining the two would produce a binary code of (1, 0). Similarly, a closed circuit between electrical contacts  116  and  118 , and a closed circuit between electrical contacts  122  and  124  would produce a binary code of (1, 1). 
       FIGS. 5A-5C  illustrate additional configurations of a circuit board  114  having four electrical contacts and two conductors. As seen in  FIG. 5A , the electrical contacts  116  and  124  are electrically connected by the conductor  126 , and electrical contacts  118  and  122  are electrically connected by the conductor  128 . In  FIG. 5B , electrical contacts  116  and  124  are electrically connected by the conductor  126 , whereas electrical contacts  118  and  122  are not electrically connected. In  FIG. 5C , electrical contacts  116  and  124  are not electrically connected, whereas electrical contacts  118  and  122  are electrically connected by the conductor  128 . These additional configurations could each produce different codes for identifying a characteristic of the medical device accessory. 
     As shown, the conductor  128  in  FIG. 5B  and the conductor  126  in  FIG. 5C  do not provide an electrical connection between electrical contacts. In other words, the circuits between the respective electrical contacts are open. The specific arrangement of these open circuits may indicate a specific characteristic of the medical device accessory. Alternatively, if a conductor initially provides an electrical connection between the respective electrical contacts and is subsequently severed, an indication may be provided that the medical device accessory has previously been used. 
     As noted above, it is envisioned that the circuit board could include a significantly larger number of electrical contacts, and any number of conductors could form electrical connections between the electrical contacts. Furthermore, it is envisioned that a single conductor could electrically connect more than two electrical contacts. In this way, numerous conductor patterns, or arrangements of electrical contacts receiving a voltage from the medical device, may be provided. These conductor patterns may indicate the presence and/or whether the medical device accessory has previously been used, as well as other characteristics of the medical device accessory. Depending on the number of electrical contacts and electrical connections provided on a single medical device accessory, it is envisioned that any number of characteristics may be identified by the medical device accessory&#39;s conductor pattern 
     For example, the indicated characteristic(s) may comprise the presence of a medical device accessory, whether the medical device accessory is properly connected to the medical device, a prior use of the medical device accessory, the identity of the medical device accessory, the compatibility of the medical device accessory with the medical device, or an operating parameter of the medical device for administration of a medical treatment using the medical device accessory. In the case of a tubing set, the conductor pattern(s) may indicate the presence of the tubing set, correct connection of the tubing set, a prior use of the tubing set, specifications of the tubing set (e.g., manufacturer, lumen diameter, length, etc.), compatibility of the tubing set, or an operating parameter of the medical device (e.g., fluid flow rate, fluid pressure, fluid temperature, etc.). 
     Turning to  FIG. 6 , an exemplary circuit diagram representing the present system is shown. The circuit shown in  FIG. 6  is intended to illustrate a medical device accessory having a circuit board with four electrical contacts and two conductors, such as shown in  FIGS. 5A-5C , and a medical device adapted to receive the same. The medical device forms the portion of the circuit to the left of the dashed line in  FIG. 6 , whereas the medical device accessory forms the portion of the circuit to the right of the dashed line in  FIG. 6 . 
     The reader portion of the circuit includes a controller  130  (e.g., a microprocessor), a first resistor  132  (labeled R 1 ), a second resistor  134  (labeled R 2 ), a first capacitor  136  (labeled C 1 ), a second capacitor  138  (labeled C 2 ), a power supply  140  or voltage source (labeled VDD), and a ground  142  (labeled GND). The resistors  132  and  134  are used for current limiting. The capacitors  136  and  138  are used to store the state of the respective wires for reading by the controller  130 , and may be omitted if the controller  130  is fast enough to read the port pins while using the port&#39;s own gate capacitance for storing the state. 
     The card portion of the circuit is illustrated in the form of a first switch  144  (labeled S 1 ) and a second switch  146  (labeled S 2 ). Although the medical device accessory does not include actual physical switches, the first switch  144  and the second switch  146  are shown in the circuit diagram of  FIG. 6  to represent the electrical connections the conductors could make between electrical contacts to accomplish a logic state. As previously mentioned, the medical device accessory does not include any active components. 
     The potential logic states for “switches”  144  and  146  are shown in  FIG. 7 . The logic states for the first switch  144  is shown in the first column  148  of  FIG. 7 . The logic states for the second switch  146  are shown in the second column  150  of  FIG. 7 . Each of the switches  144  and  146  may be in an up position, a middle (floating) position, or a down position. The up position attaches the switch to the power source  140 . The down position attaches the switch to the ground  142 . The middle, or floating, position leaves the switch open, making no contact with the power source  140  or the ground  142 . Because this approach yields three states for each conductor, a two conductor embodiment, with two contacts per conductor, will yield the  9  logic states shown in  FIG. 7 . In this embodiment, it is envisioned that a binary code, as discussed above, may be used to identify electrical connections between any two electrical contacts. Alternatively, a ternary coding scheme, representing the three logic states, may be applied to the “switches”  144  and  146  to identify the electrical connections between the electrical contacts. 
     Reading for each switch, i.e., each port of the controller  130 , is performed as illustrated in the flow chart of  FIG. 8 . Because the medical device does not know how the contacts are connected until after cycling through the reading process illustrated in  FIG. 8 , and because a user can change the medical device accessory at any time, in one embodiment, the controller on the medical device may automatically strobe through the contacts on its receptacle periodically, according to the example of  FIG. 8 , to determine what medical device accessory is attached or not. 
     In step  152 , the ports of the controller are driven High (VDD), which charges the capacitors  136  and  138 . In step  154 , the ports of the controller  130  are then configured as inputs. In step  156 , the controller  130  reads the state of the port pins, and if a port pin is read as being Low (GND), then the position of the corresponding switch must be Low. In other words, because the controller  130  provided a High signal to charge the capacitor, the capacitor would have remained High if the switch were floating or connected to VDD. 
     Next, in step  158 , the ports of the controller are driven Low. In step  160 , the controller  130  configures the port pins as inputs. In step  162 , the controller  130  then reads the state of the port pins, and if a port pin is read as being High, then the position of the switch must be High. In other words, because the controller  130  provided a Low signal, the capacitor would have remained low if the switch were floating or connected to GND. Consequently, if the input pin corresponding to a switch changed each time the port pin was driven, then the state of the switch must be floating. 
     The equivalent circuit of  FIG. 6  and the associated state table of  FIG. 7  relates to a circuit board with 2 conductors, each having 2 contacts, such as that shown in  FIGS. 3 and 5 . Each conductor, when attached to the medical device, could be measured by the medical device reader/adapter as High (VDD), Low (GND) or Floating (severed). As each conductor could represent 3 possible states, the number of possible states for the combination is 9 (i.e., 3 2 ). Because the circuit board  114  is passive, in the sense that there is no active switch or other component, the manufacturer of the medical device accessory having the circuit board  114  can manufacture the medical device accessory with a particular combination of conductor-contact connections to identify that particular type or version of medical device accessory to the medical device. 
     Turning to  FIG. 9 , a perspective view of an alternative embodiment of a medical device accessory  200  is shown. In this embodiment, the medical device accessory  200  is adapted to connect a medical device to another medical device accessory, i.e., as an intermediate connector. For example, the medical device accessory  200  is adapted to connect a pre-existing tubing set with a medical device. However, like the medical device accessory  100 , the medical device accessory  200  may be adapted to connect any number of different medical device accessories with any number of medical devices without departing from the principles and concepts described herein. 
     The medical device accessory  200  shown in  FIG. 9  comprises an interface, in the form of a port  210 , for engaging a medical device, and a barbed nipple  211  adapted to engage a medical tubing set (not shown). The medical device accessory  200  further includes an electrical housing  212  for housing a circuit board (not shown), and a plurality of electrical contacts  216  extending therefrom. The electrical contacts  216  on the medical device accessory  200  are presented in the form of pins, however any other suitable form of electrical contacts may be used. The medical device accessory  200  further includes a positioning post  215  for insuring proper alignment of the medical device accessory  200  upon its connection with a medical device, such that the plurality of electrical contacts  216  engage corresponding electrical contacts on the medical device. The medical device  200  is otherwise used and operated as described in relation to the above embodiments. 
     Referring to  FIGS. 10 and 11 , another embodiment of a medical device accessory  300  and an identification device  364  is shown. Although the following description refers to an embodiment wherein the medical device accessory  300  is a medical tubing set, as with the previously described embodiments, those skilled in the art will appreciate that the disclosed concepts and principles may be applied to any medical device accessory, or may be embodied in a separate accessory adapted to connect a medical device to another medical device accessory, i.e., as an intermediate connector. As described below, the identification device  364  may be associated with a medical device and is adapted for use with the medical device accessory  300 . However, it will be appreciated that the medical device accessory  300  may be useable with other suitable identification means associated with all types of medical devices. 
     Notably, the medical device accessory  300  provides a way to communicate the presence and characteristics of the medical device accessory  300  to a medical device without the use of any electrical or active elements located on the medical device accessory  300 . Rather, as explained below, the system can be implemented with inexpensive manufacturing and the inclusion of various structural features on the medical device accessory  300 . This system, like the previously described system, has in comparison to the prior art, ease of manufacture, very low cost, multiple configurations, an inexpensive means for disabling use of the accessory, basic electronics for measuring voltage or current, and ease of programming using basic binary concepts. 
     In general, the medical device accessory  300  is comprised of a connector  302  disposed at an end of a tube  304 . The connector may include a female end  306  for receiving the tube  304 , a conduit (not shown) running through the connector  302 , and a male end  310  adapted to engage a suitable corresponding connection on a medical device, for example, a tubing nipple or a luer. It is envisioned that the connector  302  may be separate from the tube  304 , or the connector  302  may be integrally formed with medical device accessory. 
     The connector  302  further comprises a housing  312 . Preferably, the housing  312  is proximate to the interface, i.e., the male end  310  of the connector  302 , such that the connection of the medical device accessory  300  with the medical device is unobtrusive. As shown in  FIG. 10 , three tabs  314  are disposed within the housing  312 . Although the connector  302  in  FIG. 10  is shown with three tabs  314 , it is envisioned that the connector  302  may have as few as one tab  314 , or many more tabs  314 , for example, positioned in multiple rows. Furthermore, although the tabs  314  in  FIG. 10  are positioned side-by-side, it is envisioned that the tabs  314  may be displaced relative to one another to create numerous unique arrangements. 
     One or more of the tabs  314  may also be configured to break when a threshold insertion pressure is applied to the tab  314  upon connection of the medical device accessory  300  with a medical device. As used herein, the term “break” or “breakable” should be broadly interpreted to include all forms of breaking, including for example, deflecting, bending, stretching, tearing, shattering, removal, etc., and any other change in the structural integrity of a tab  314  such that a tab  314  is no longer able to withstand the threshold pressure. In this way, detection of a broken tab  314  by a medical device may indicate a prior use of the medical device accessory  300 . For example, if the connector  302  is made of plastic via a molding operation, the web strength of one or more particular tabs  314  may be selected so that they are breakable upon connection of the medical device accessory  300  with a medical device. 
     As noted above, the connector  302  is useable with the identification device  364 , which may be positioned on the medical device proximate a point of connection for the medical device accessory  300 . In general, the identification device  364  of  FIG. 11  comprises a housing  366 , an arrangement of three switching elements  368 , and three pairs of pins  370 . The housing  366  of the identification device  364  is shown in  FIG. 11  independent of a medical device, however it is envisioned that the identification device  364  and the housing  366  may be formed integrally with a medical device, or as a component that is selectively removable and replaceable. 
     The switching elements  368  are disposed within the housing  366 . A proximal end of each switching element  368  extends beyond the housing  366  and is configured to engage a corresponding tab  314  on the medical device accessory  300 , assuming a corresponding tab  314  is provided in the arrangement of tabs  314  on the medical device accessory  300 . Attached to the distal end of each switching element  368  is a pair of pins  370 . 
     The switching elements  368  and the pins  370  are configured to slide axially in the distal direction between a first position (as shown in  FIG. 11 ), when the medical device accessory  300  is not connected to the medical device, and a second position (not shown), when the medical device accessory  300  is connected to the medical device and a corresponding tab  314  is provided in the arrangement of tabs  314  on the medical device accessory  300 . The switching elements  368 , and therefore the pins  370 , are biased toward the first position, for example, by a spring  372 , positioned concentrically about each switching element  368 . Other biasing means may alternatively be used. In this way, the switching elements  368  and the pins  370  are configured to slide from the first position to the second position in response to pressure applied to the switching elements  368  by corresponding tabs  314  on the medical device accessory  300  upon connection of the medical device accessory  300  to the medical device, and to return to the first position upon disconnection of the medical device accessory  300  from the medical device, or alternatively, after a tab  368  breaks upon application of the threshold insertion pressure. 
     Although the identification device  364  shown in  FIG. 11  has three switching elements  368 , it is envisioned that the identification device  364  could have as few as one switching element  368 , or many more switching elements  368 , for example, positioned in multiple rows, such that a switching element  368  corresponds to each tab  314  of the medical device accessory  300 . It is also envisioned that the number of switching elements  368  provided within the identification device  364  may be greater than the number of tabs  314  provided on the medical device accessory  300 , for example, to accommodate other medical device accessories having a different number or arrangement of tabs  314 . 
     As with the previously described embodiments, the medical device of this system may include a controller and simple circuitry for reading and determining the presence and correctness of the medical device accessory  300 , which as previously noted, does not include any electrical or active elements. For example, in the second position, the pins  370  may engage a port on the medical device (not shown) having circuitry similar to that shown in  FIG. 6  and described above. By sensing if one or more particular pins  370  have engaged the port (i.e., moved to the second position), if one or more particular pins  370  remain engaged, or if one or more tabs  314  break after engagement, such that the one or more corresponding pins  370  return to the first position, the controller may determine any number of characteristics of the medical device accessory  300 , including for example, the presence of the medical device accessory  300 , whether the medical device accessory  300  is properly connected, a prior use of the medical device accessory  300 , the identity of the medical device accessory  300 , the compatibility of the medical device accessory  300  with the medical device, or an operating parameter of the medical device accessory  300  for administration of a medical treatment using the medical device accessory  300 . Based on the determination, the system may, for example, provide an indication that the medical device accessory  300  is not present, or that the medical device accessory  300  has previously been used, or that the medical device accessory  300  is not compatible with the medical device, etc. Alternatively, the medical device may, for example, adjust the operating parameters of the medical device for use with the particular medical device accessory  300 . 
     The foregoing description of has been presented for purposes of illustration and description, and is not intended to be exhaustive or to limit the inventions to the precise forms disclosed. It will be apparent to those skilled in the art that the present inventions are susceptible of many variations and modifications coming within the scope of the following claims.