Abstract:
This invention relates to methods, apparatuses and systems for testing the functionality of the pumping mechanism of a medical device, e.g., an implantable infusion pump, while the medical device is contained within a shipping package. The test apparatus enables such functional verification, without opening the shipping package, when the medical device is still contained within the package that has been appropriately sealed to maintain sterility of the medical device.

Description:
RELATED APPLICATION 
     This application is a divisional of application Ser. No. 11/222,161, filed Sep. 8, 2005, now U.S. Pat. No. 7,604,614, which claims the benefit of U.S. Provisional Application 60/625,429, filed Nov. 5, 2004, which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to a method and apparatus for testing the functionality of a medical device, e.g., an implantable infusion pump, while the device is still contained within a sterile shipping package. 
     BACKGROUND OF THE INVENTION 
     Applications exist which require that devices be kept in a sterile package prior to use. For example, it is generally understood in the medical community that contaminants or infectious material should not be introduced into the human body. To that end, medical devices, and particularly devices intended for implantation in the body, such as infusion pumps, are preferably assembled under sterile conditions and shipped in packages which are appropriately sealed to maintain the sterile environment. Such packages generally remain sealed until they are opened immediately prior to surgically implanting the device. 
     It is, of course, important to verify that the device is operable, i.e., functional, prior to implanting. To assure the availability of at least one functional device, it is common practice to supply multiple devices to the surgical location prior to implantation. This practice can be inconvenient, can introduce delays in surgery, and can increase costs. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a method and apparatus which enables the functionality of a medical device for discharging fluid, e.g., an implantable infusion pump, to be verified while the device is contained in a sterile package. More particularly, the invention is concerned with medical devices which include an actuatable fluid transfer mechanism, e.g., a pump and/or valve mechanism. 
     In accordance with the invention, the medical device will be placed in a package prior to shipment from its place of manufacture. The package is then appropriately sealed to establish a sterile environment for the device. Subsequently, and before opening the package to access and use the device, the device is actuated, e.g., by an RF command signal transmitted from outside of the package, and the response of the device is then monitored. An indication is then produced, recognizable by a responsible user, to indicate whether the device is functional, i.e., whether or not the monitored response satisfies some predetermined criteria. 
     In a preferred embodiment, the medical device comprises an implantable infusion pump with a case and an outlet port (or “outlet”). A simple low cost test apparatus (or “indicator”) is coupled to the outlet port of the infusion pump prior to placing the pump into the package. The test apparatus is configured to detect pump activity (e.g. a fluid discharge and/or a pressure change at the outlet port) and provide an indication thereof, e.g., visual and/or aural, recognizable by a responsible person. Prior to opening the package, the infusion pump is actuated (while still in the package) by a command signal generated by a transmitter externally of the package and communicated to a receiver within the infusion pump. In other words, an indicator may be located within the sealed interior and outside the pump case, in fluid communication with the outlet, and configured to provide an indication that is discernible outside the package in response to a fluid discharge at the outlet and/or a pressure change at the outlet. 
     A preferred test apparatus in accordance with the invention is coupled to an infusion pump&#39;s catheter outlet port and is configured to provide a visual indication in response to pump activity (i.e. fluid discharge and/or pressure change) at the outlet port. The indication is visible externally of the package through a transparent portion or window in the package. In other words, the indicator may be connected to the outlet and is configured to (or has an indication device that is configured to) provide a visible indication in response to a fluid discharge at the outlet and/or a pressure change at the outlet. Thus, without opening the sterile package, a responsible person can determine whether the pump is functioning in response to the externally generated command signal. 
     A preferred test apparatus in accordance with the invention includes an elongate tube having its open proximal end coupled to the pump&#39;s outlet port. The tube contains a column of gas, e.g., air, and a sealed distal end. As liquid is discharged from the outlet port into the tube, the liquid moves the gas/liquid interface, which can be visually observed by the responsible person through the window in the package. 
     In alternative embodiments of the invention, a flexible membrane, or a piston, can be coupled to the pump outlet port in lieu of the elongate tube to exhibit physical movement in response to a fluid discharge and/or pressure change from the port. In a further alternative embodiment, the visual indication can comprise a light source which can be activated in response to detected pump activity. 
     In a yet further alternative embodiment of the invention, the test apparatus can be configured to produce an aural indication in response to detected pump activity. For example, a buzzer, bell, chime, etc., can be activated to provide a sound recognizable by the responsible person. 
     In a still further embodiment, the test apparatus can transmit a signal externally of the package to indicate detected pump activity. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  is a block diagram of an exemplary implantable infusion pump, connected to a test apparatus in accordance with the invention, within a shipping package; 
         FIG. 2  is a plan view of an exemplary implantable infusion pump, connected to a test apparatus in accordance with the invention, within a shipping package; 
         FIG. 3  is an enlarged plan view of the exemplary infusion pump of  FIG. 2  (with the shipping package omitted) illustrating the test apparatus in greater detail; 
         FIG. 4  is a plan view of an exemplary infusion pump connected to an alternative embodiment of the invention using a membrane; 
         FIG. 5  is a plan view of an exemplary infusion pump connected to an alternative embodiment of the invention using a piston; 
         FIG. 6  is a plan view of an exemplary infusion pump connected to an alternative embodiment of the invention using a light source; and 
         FIG. 7  is a plan view of an exemplary implantable infusion pump connected to a further alternative embodiment of the invention using a sound source. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates an exemplary block diagram of a medical device, e.g., an implantable infusion pump  20 , connected to a test apparatus  22  in accordance with the invention. The pump  20  and apparatus  22  are configured to be placed within an interior cavity  24  of a shipping package  26  that may be sufficiently transparent to permit viewing of movement of an indicator (discussed below) within the package. A transparent cover  28  overlays and appropriately seals the cavity  24  at its boundary  29  to maintain a sterile environment (i.e., a sterile sealed interior) within the shipping package  26  in the illustrated embodiment. Once the infusion pump  20  and test apparatus  22  are sealed in the shipping package  26 , the functionality of the infusion pump  20  can be verified by transmitting a command signal, e.g., RF, from an external transmitter  30  to a receiver  32  within the case  34  of the implantable infusion pump  20 . 
     Typical implanted infusion pumps include a receiver and/or transceiver for receiving telemetry data and critical signals from an external transmitter and for transmitting patient and/or infusion pump condition data to an external (non-implanted) control unit or monitoring station. It is contemplated that such a receiver and/or transceiver be used as the receiver  32  in accordance with the present invention. In response to the command signal, the receiver  32  actuates a fluid transfer device  36 , e.g., a pumping mechanism, within the case  34  to transfer fluid, e.g., liquid, from a reservoir  37  in the case  34  for discharge through the infusion pump&#39;s  20  outlet port. The test apparatus  22  in accordance with the present invention functions to detect actuation of the mechanism  36 , as by sensing whether a fluid discharge has occurred. 
       FIG. 2  illustrates an exemplary implantable infusion pump  20  connected to a preferred test apparatus  22  in accordance with the invention. The infusion pump  20  and apparatus  22  are shown mounted in an exemplary sterile shipping package  26 . The boundary seal  29  of the transparent cover  28  maintains the infusion pump  20  in a sterile environment preventing contamination unless the integrity of the transparent cover  28  or boundary seal  29  is compromised. The shipping package  26  schematically depicted in  FIG. 2  is exemplary only but representative of various types of packaging which can be used with the test apparatus  22 . Alternatively, the test apparatus  22  is suitable for use with any sealed bag or other container having a transparent area through which a visual indication produced by the test apparatus  22  can be viewed. 
     Attention is now directed to  FIG. 3  which illustrates in greater detail a preferred embodiment of the test apparatus of  FIG. 2 . The test apparatus  22  (or “indicator”) comprises an indication device in the form of a tube that has sufficient transparency to enable fluid movement within the tube to be observed outside of the tube (e.g., the exemplary transparent tube  38 ) having a proximal end  40  attached to the catheter outlet port  42  of the infusion pump  20 . When the receiver  32  ( FIG. 1 ) receives a command signal from the transmitter  30 , it actuates the pumping mechanism  36  to define an operating state which transfers liquid from reservoir  37  ( FIG. 1 ) for discharge through the catheter outlet port  42  into the transparent tube  38 . In other words, one exemplary indicator may be a tube that is connected to the outlet and is sufficiently transparent to permit a user to visually observe fluid movement within the tube. The movement of liquid through the tube  38  is visible through the transparent cover  28  and provides a visual indication of functionality of the infusion pump  20  to a responsible observer. 
     In a preferred embodiment, the tube  38  is filled with sterile liquid  43 , e.g., the same liquid used to fill the reservoir  37  ( FIG. 1 ) prior to shipment. The liquid in the tube  38  preferably contains a short column of gas, e.g., air  44 . After filling, the tube  38  is attached to the catheter outlet port  42  of the implantable infusion pump  20 . When the pumping mechanism  36  is actuated in response to a command signal received by receiver  32  ( FIG. 1 ), liquid discharged from the outlet port  42  will move the liquid/gas interface  46  inside the tube  38 . The movement of the interface  46  can be readily observed through transparent cover  28 , indicating proper operation of the implantable infusion pump  20 . 
     In most applications, it is preferable to seal the distal end  48  of the tube  38  with a cap/plug  50 , of a material such as silicone, to prevent evaporation or leakage of liquid. If the tube  38  is sealed with a cap/plug  50 , the tube  38  can be marked with calibration or volume marks  52  to indicate the actual volume of liquid pumped into tube  38 . If leakage or evaporation is not an issue and the need to measure fluid discharge is not required, the distal end  48  of the tube  38  need not be sealed, so long as the tube has sufficient capacity to accommodate the liquid discharge. 
     The tubing  38  is preferably coiled around the implantable infusion pump  20  such that its entire length is visible through the transparent cover  28  (not shown in  FIG. 3 ). The specific dimensions of the tube  38  can vary dependent upon the size of the implantable infusion pump  20 . It must, of course, be long enough to accommodate a volume of discharged liquid sufficient to verify pump functionality. An exemplary tube length could be approximately 22 inches or roughly three times the circumference of the exemplary infusion pump  20 . An exemplary tube inner diameter could be about 0.047 inches, approximately equal to the diameter of a catheter for which the outlet port  42  is sized. 
     Visual indications of pump activity can be produced in alternative ways. For example,  FIG. 4  shows a test apparatus (or “indicator”) that includes an indication device in the form of a short tube  53  coupling the outlet port  42  to a flexible (or “distendible”) membrane  54 . When the pump is activated to pump liquid out of port  42 , the liquid discharge will cause the membrane  54  to distend. This membrane distention can be visually observed through the transparent cover  28  to indicate pump functionality. 
       FIG. 5  illustrates another alternative visual indication embodiment of the test apparatus (or “indicator”) in which indicator includes an indication device in the form of a slidable piston  56  that is used in lieu of the membrane  54  of  FIG. 4 . In  FIG. 5 , the liquid discharge from port  42  will produce a pressure on piston  56  which acts on the piston  56  to slide it outwardly from supporting sleeve  57 . 
       FIG. 6  illustrates a further alternative visual indication embodiment of the test apparatus (or “indicator”) in which the indicator includes an indication device in the form of a light source and also includes a switch. Liquid discharged from port  42  operates a switch (not shown) to activate a light source  58  which can be visually observed through the transparent cover  28  to indicate pump functionality. 
       FIG. 7  depicts a still further embodiment of the test apparatus (or “indicator”) in which the indicator includes an indication device in the form of a sound generator (or “source”)  60 , e.g., a buzzer, chime, etc., for responding to liquid discharge from port  42  to produce an audible signal. 
     In a still further alternative embodiment, the sensing of pump activity after receipt of an externally transmitted command signal causes a transceiver internal to the infusion pump to transmit an indicating signal externally of the sterile package. This indicating signal can then be recognized by an external (non-implanted) control unit or other monitoring device to alert the responsible person. 
     From the foregoing, it should now be appreciated that an inexpensive test apparatus has been described for testing the functionality of an infusion pump while still contained in its sterile shipping package. Although only a limited number of embodiments have been illustrated, it is recognized that variations and modifications will occur to those skilled in the art coming within the spirit and scope of the invention as defined by the appended claims.