Abstract:
A method of substituting an MRI incompatible pump for delivering fluid to a patient with an MRI compatible pump, both pumps being microprocessor controlled. The first pump operates upon administration tubing for pumping fluid from a source thereof to the patient. The method includes the steps of: providing the second pump to be substituted for the first pump; providing second tubing having a portion thereof that is operable to function with the second pump; connecting the second tubing to the administration tubing to establish an altered fluid path from the source to the patient, the altered path including portions of both the administration and second tubing; placing the second pump for operation upon the second tubing to enable the second pump to pump the fluid through the altered path according to programming thereof; and disconnecting the first pump from the administration tubing before bringing the patient into the MRI environment.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   This application claims the benefit of U.S. Provisional Application Ser. No. 60/304,386, filed on Jul. 10, 2001, the contents of which are hereby incorporated by reference. 

   BACKGROUND OF THE INVENTION 
   The present invention relates to devices, systems and methods for infusion of fluid, and especially, to devices, systems and methods for use in the vicinity of a magnetic field of a magnetic resonance imaging system. 
   Magnetic resonance imaging (MRI) is used to image the body in a non-invasive manner. There are three types of electromagnetic fields used in MRI: a main static magnetic field (having field strengths from, for example, approximately 0.2 to several Tesla) which is generally homogeneous in the imaged volume; time varying magnetic gradient fields (G x , G y  and G z ), which have different orientations and operate at frequencies on the order of 1 kHz; and a radio frequency (“RF”; having, for example a frequency of approximately 63.87 MHz for a 1.5 Tesla static field strength). 
   MRI is often scheduled to image patients that may be attached to other types of equipment, such as ventilators, infusion pumps, or other devices. However, most of these devices fail to operate correctly in the high magnetic fields generated in MRI, create undesirable artifacts in the resultant image, and/or contain ferrous materials that are susceptible to magnetic fields. As a result, there are a substantial number of MRI procedures that are severely hampered, delayed or canceled because the patient cannot be connected to the needed equipment during the MRI procedure. A review of issues related to the compatibility of various equipment in an MRI environment is set forth in Keeler, E. K. et al., “Accessory Equipment Considerations with Respect to MRI Compatibility,”  JMRI,  8, 1 (1998), the disclosure of which is incorporated herein by reference. See also, Lemieux, L. et al., “Recording of EEG During MRI Experiments: Patient Safety,”  MRM,  38, 943 (1997); and “A Primer on Medical Device Interactions with Magnetic Resonance Imaging Systems,” U.S Food and Drug Administration—Center for Devices and Radiological Health (Feb. 7, 1997), the disclosures of which are incorporated herein by reference. 
   For example, many patients in intensive care or similar units receive one or more drugs necessary to stabilize vital body systems/functions intravenously with use of an infusion pump. Often, such patients, cannot be disconnected from the drug source/infusion pump for even the relatively short period of time required to perform an MRI scan. If the infusion pump is incompatible with an MRI environment, the procedure must be delayed until the patient is sufficiently stable to be removed from the infusion pump, the procedure must be foregone, or a very long tubing set must be used that allows the infusion pump to be maintained a safe distance from the MRI magnet. Even in the case that a long tubing set can be used, problems persist including, but not limited to, tripping hazards created by the lengthy tubing set, an undeliverable or wasted volume of often expensive medication contained within the length tubing set, inaccuracy in the control of flow/volume and inaccessibility of infusion pump controls to operators. 
   In general, many devices, including but not limited to infusion pumps, that contain electric actuators such as DC brush motors, step motors, brushless DC motors or other wound coil motors and solenoids often fail in a strong magnetic field as a result of damage to internal permanent magnets. Moreover, currents induced within the field windings of such devices from electromagnetic fields can cause overheating and potential damage to the windings and any connected electronic circuitry. The MRI magnetic field can also interfere with the device created magnetic field and prevent accurate operation. 
   Furthermore, differences in magnetic permeability of materials within the actuator and eddy currents induced within actuator windings can affect the homogeneity or uniformity of the MRI magnetic field, generating image artifacts. Actuators that use mechanical commutation, such as DC brush motors, can also generate radio frequency energy during switching which can induce unwanted artifacts upon the acquired MRI images. 
   To prevent damage to sensitive equipment in MRI procedures, U.S. Pat. No. 4,954,812 discloses a magnetic field alarm indicator to detect when the ambient magnetic field reaches unacceptable levels for equipment operation. After an alarm indication, the equipment can be moved farther from the MRI magnet or disconnected from the patient. An alarm indication can be of limited effectiveness, however, if the equipment must be placed physically close to the patient, such as for fluid administration, or if the equipment must be closely connected to the patient. The use of a magnetic field alarm indicator as disclosed in U.S. Pat. No. 4,954,812 also does not address the problems of unwanted effects on magnetic field homogeneity and commutation or switching artifacts. 
   A number of medical devices have been designed to operate within the relatively high magnetic field environment used for MRI. For example, U.S. Pat. No. 5,494,036, discloses an injector system that provides for decreased interference between the magnetic field used for producing diagnostic images and the magnetic fields generated by the electric motors used for driving the pistons of the contrast media injectors. Japanese Patent Application HEI 7-178169 and German Patent Application DE 197 14 711 A1 disclose use of piezoelectric-based actuators such as ultrasonic motors in an MRI environment in an effort to reduce the adverse effects experienced with other actuators. 
   Because of certain modifications that may be necessary for devices designed to operate within an MRI environment (that is, within the general environment present in the vicinity of an MR scanner), such devices can be considerably more expensive than similar devices not designed to operate in an MRI environment. Moreover, the functionality and/or operation of devices designed to operate within an MR environment can be different from similar devices not designed to operate in an MR environment. 
   Given, for example, the criticality of continuous administration of vital system maintenance drugs to certain patients, it is very desirable to develop systems, methods and devices for facilitating use of devices designed to operate within an MRI environment. 
   SUMMARY OF THE INVENTION 
   In one aspect, the present invention provides a tubing set including a length of tubing having at least a section thereof that is fabricated to function with an infusion pump. The tubing set further preferably includes a first valve that is removably connected to the length of tubing on a first end thereof. The first valve is preferably in a closed state when disconnected from the length of tubing. The tubing set also preferably includes a second valve on a second end thereof. The second valve is preferably in a closed state until connected to another fluid path component. The tubing set is preferably suitable for use in an MR environment. 
   The first valve can, for example, include a housing and a closing member that is biased in a closed position when the first valve is removed from connection with the length of tubing. The closing member can extend outside of the housing when in a closed position for ease of aseptic cleaning. 
   The second valve can be biased in a closed position when the second valve is connected to the length of tubing and prior to connection of the second valve to another fluid path component. For example, the second valve can include a housing and a closing member that is biased in a closed position. The closing member of the second valve can extend outside of the housing when in a closed position. 
   In another aspect, the present invention provides a method of replacing at least a first infusion pump in connection with a patient with at least a second infusion pump including the steps: closing a length of patient tubing connected to a patient to prevent backflow of blood therethrough, the patient tubing being in fluid communication at a first end thereof with a length of administration tubing, the administration tubing being in operative connection with the first infusion pump and being in fluid connection with a source of fluid, the patient tubing being in fluid connection with a patient catheter at a second end thereof; disconnecting the patient tubing from the administration tubing; connecting an intermediate length of tubing to the administration tubing, the intermediate tubing including at least a section thereof that is fabricated to function with the second infusion pump; placing the second infusion pump in operative connection with the intermediate tubing; removing the first infusion pump from operative connection with the administration tubing; and connecting the intermediate tubing to the patient tubing. As clear to one skilled in the art, the order of certain of the steps set forth in the above method (and other methods set forth below) may not be important to the overall operability or effectiveness of the method. 
   The method can further include the step of priming the intermediate tubing with fluid after connection thereof with the administration tubing. The intermediate tubing can, for example, be primed using the first infusion pump. The intermediate tubing can also be primed using the second infusion pump. 
   In one embodiment, the second infusion pump is more suitable for use in an MR environment than the first infusion pump. 
   The intermediate tubing can be connected to the patient tubing via a valve that is removably connected to the intermediate tubing. This valve can be in a closed state when disconnected from the intermediate tubing as described above. The method can further include the step of disconnecting the patient tubing from the intermediate tubing while leaving the valve connected to the first length of tubing. The method can also further include the steps of: disconnecting the administration tubing from the intermediate tubing; connecting the patient tubing to the administration tubing via the valve; and placing the first infusion pump in operative connection with the administration tubing. The valve can be disinfected prior to connecting the valve to the administration tubing. As described above, the valve can include a housing and a closing member that is biased in a closed position when the valve is removed from connection with the intermediate tubing. Once again, the closing member can extend outside of the housing when in a closed position to facilitate disinfecting or aseptic cleaning. 
   In the method, a first plurality of infusion pumps can be replaced by a second plurality of infusion pumps. For example, the second plurality of infusion pumps can be more suitable for use in an MR environment than the first plurality of infusion pumps. Likewise, a first multi-channel infusion pumps can be replaced by a plurality of infusion pumps. Moreover, a first plurality of infusion pumps can be replaced by second, multi-channel infusion pump. 
   In another aspect, the present invention also provides a method of replacing at least a first infusion pump in connection with a patient with at least a second infusion pump. The first infusion pump is in fluid connection with a length of patient tubing connected to a patient at one end and removably connected to a length of administration tubing at another end. The administration tubing is in fluid connection with a source of fluid and in operative connection with the first infusion pump. The method includes the steps: disconnecting the patient tubing from the administration tubing; connecting a length of intermediate tubing between the patient tubing and the administration tubing, the intermediate tubing including at least a section thereof that is fabricated to function with the second infusion pump; placing the second infusion pump in operative connection with the intermediate tubing; and removing the first infusion pump from operative connection with the administration tubing. 
   In a further aspect, the present invention provides a method of substituting at least a first infusion pump in connection with a patient with at least a second infusion pump for a period of time. As described above, the first infusion pump is in fluid connection with a length of patient tubing connected to a patient at one end and removably connected to a length of administration tubing at another end. The administration tubing is in fluid connection with a first source of injection fluid and in operative connection with the first infusion pump. The method includes the steps of: disconnecting the patient tubing from the administration tubing; connecting a length of intermediate tubing to the patient tubing, the intermediate tubing including at least a section thereof that is fabricated to function with the second infusion pump, the intermediate tubing further including a first valve removably connected on a first end thereof, the first valve being closed when disconnected from the intermediate tubing; connecting the intermediate tubing to the first source of injection fluid or to a second source of injection fluid; placing the second infusion pump in operative connection with the intermediate tubing for the period of time; and after the period of time, disconnecting the patient tubing from the intermediate tubing while leaving the first valve connected to the first length of tubing. 
   In another aspect, the present invention provides a method of substituting at least a first infusion pump in connection with a patient with at least a second infusion pump. The first infusion pump is in operative connection with a length of administration tubing, which is in fluid connection with a source of injection fluid and with the patient. The administration tubing includes at least one port. The method includes the steps of: connecting a length of a second tubing to the port of the administration tubing; the second tubing including at least a portion thereof that is fabricated to function with the second infusion pump; connecting the second tubing to the source of injection fluid; placing the second infusion pump in operative connection with the second tubing; and removing the first infusion pump from operative connection with the administration tubing. For example, the port of the administration tubing can be part of a Y-connector, T-connector, manifold or other similar fluid path element. 
   In still a further aspect, the present invention provides a replacement infusion pump system including: an infusion pump and a tubing set having a length of tubing. The length of tubing includes at least a section thereof that is fabricated to function with the infusion pump. The infusion pump and the tubing set are suitable for use in an MR environment. In one embodiment, the tubing set further includes a first valve removably connected on a first end of the length of tubing. The first valve is in a closed state when disconnected from the length of tubing as described above. The tubing can further include a second valve connected on a second end of the length of tubing. The second valve can be in a closed state when connected to the length of tubing until connected to another fluid path element. The system can further include an adapter to place an administration tubing set of another infusion pump in a free flow state after the other infusion pump has been removed from operative connection with the administration tubing set. The length of tubing can include at least one Y-connector to provide a connection port thereon in addition to the tubing ends. 
   The present invention provides for simple and efficient replacement or substitution of at least one infusion pump with at least one other infusion pump (for example, having different utility than the first infusion pump). Air is readily removed from the fluid path before infusion into the patient. Moreover, the tubing set(s) provided with or used with the first infusion pump is/are typically maintained in the fluid path system, facilitating airless reconnection of the first infusion pump and reducing complexity and cost. Furthermore, sterility is maintained throughout the process of substituting one pump for another and waste of injection fluid is minimized. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  illustrates a currently available infusion pump system in a disconnected state. 
       FIG. 2  illustrates the infusion pump system of  FIG. 1  in a connected state and in fluid connection with a source of injection fluid. 
       FIG. 3A  illustrates an embodiment of a replacement infusion pump system of the present invention including an infusion pump and a tubing set for use with the infusion pump. 
       FIG. 3B  illustrates another embodiment of a tubing set for use with the infusion pumps of the present invention. 
       FIG. 4A  illustrates removal of the tubing set of the present invention from its packaging and removal of an end cap therefrom in preparation for connection to the fluid path of  FIG. 2 . 
       FIG. 4B  illustrates two embodiments of packaging components for efficient packaging and connection of the tubing sets of the present invention. 
       FIG. 5  illustrates the closing of the patient tubing of the fluid path of  FIG. 2  to prevent backflow therethrough. 
       FIG. 6  illustrates detachment of the patient tubing from the administration tubing in preparation for incorporation of the tubing set of the present invention. 
       FIG. 7  illustrates attachment of the tubing set of the present invention to the administration tubing of  FIG. 2 . 
       FIG. 8  illustrates connection of the replacement infusion pump to the tubing set of the present invention. 
       FIG. 9  illustrates removal of the original infusion pump from operative connection with the administration tubing. 
       FIG. 10  illustrates connection of the tubing set of the present invention to the patient tubing. 
       FIG. 11  illustrates disconnection of the tubing set of the present invention from the patient tubing after an injection using the replacement infusion pump. 
       FIG. 12  illustrates reconnection of the original pump to the administration pump. 
       FIG. 13  illustrates disconnection of the replacement pump from the tubing set of the present invention and disconnection of that tubing set from the administration tubing. 
       FIG. 14  illustrates reconnection of the patient tubing to the administration tubing. 
       FIG. 15A  illustrates a dual pump system of the present invention. 
       FIG. 15B  illustrates a multi-channel infusion pump of the present invention. 
       FIG. 16  illustrates a system of the present invention including four infusion pumps connected to four tubing sets. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   In one aspect, the present invention provides a system and method for replacing a fluid pump (for example, an infusion pump) that is not designed for use in a particular environment or in a particular manner with a fluid pump that is designed for or better equipped for that environment or that manner of use. For example, an infusion pump not well suited for ambulatory use can be replaced by an infusion pump better suited for ambulatory use. In one embodiment, the present invention provides a system and method of replacing an infusion pump not designed for or not well suited for use in an MR environment with an infusion pump that is better designed for or more suitable for use in an MR environment (referred to hereinafter generally as an MR infusion pump). Infusion pumps and other fluid pumps indicated to be suitable for use in an MR environment include the Volumed μVP5000 available from Arcomed AG of Regensdorf, Switzerland, an infusion pump available from Ulrich GmbH &amp; Co. KG of Ulm, Germany, the TomoJet MR available from Bruker AG of Fallanden, Switzerland and the BodyGuard Ambulatory Infusion Pump available from Caesarea Medical Electronics, Ltd. Of Caesarea, Israel. Allowing use of an MR infusion pump in an MR environment reduces the length of tubing required and places the infusion pump near to the operating personnel to facilitate control thereof. 
   As used herein, the term “infusion” refers to the generally continuous, slow introduction of fluid into the body, and especially into a vein. As used herein, the term “infusion pump” refers to low infusion rate pressurizing devices used in administering or infusing medical fluids. One skilled in the art will recognize that the benefits and advantages of the systems and method described herein also apply to other non-infusion types of fluid delivery. 
     FIGS. 1 through 14  illustrate one embodiment of a system and method as described above. In  FIG. 1 , a Colleague™ infusion pump  10  and associated administration tubing set  30  available from Baxter Healthcare Corporation of Deerfield, Ill. is illustrated. Tubing set  30  includes a barrett tube  40  having a spike  50  for forming a fluid connection with, for example, a standard IV bag  110  (see  FIG. 2 ). The end of barrett tube  40  opposite spike  50  is in fluid connection with tubing  60  that is designed, fabricated or calibrated specifically (for example, having a specific inner diameter, outer diameter, durometer etc.) for use with infusion pump  10  as known in the art. Tubing  60  includes a pump key  62  that is required to operate with infusion pump  10 . A roll clamp  66  is provided to stop flow through tubing set  60  if desired. Tubing set  30  also includes a Y-connector  70  including a port  72  for connecting another fluid source, manual syringe etc. to tubing set  60  as known in the art. Tubing set  30  terminates with a male luer connector  80 . An extension set or patient tubing set  90  for tubing set  30  can also be provided. Extension set  90  includes a female luer connector  92  (to form a fluid connection with male luer connector  80 ) in fluid connection with a length of tubing  94 . Tubing  94  terminates with a male luer connector  96 . An IV catheter  100  can be attached to male luer connector  96 .  FIG. 2  illustrates infusion pump  10 , tubing set  30 , extension set  90  and catheter  100  in operative connection with IV bag, bottle or other injection fluid container  110 . 
     FIG. 3A  illustrates an MR infusion pump  200  (for example, the BodyGuard Ambulatory Infusion Pump described above) and an associated fluid path or tubing set  300  that can be used to continue patient infusion in an MR environment. Tubing set  300  includes, on one end thereof, a fluid path component for stopping flow (when flow is not desired) such as an aseptic reflex valve  310  (for example, the Burron Aseptic Luer No. S5403000 available from the Burron OEM Division of B. Braun Medical of Bethlehem, Pa.). Other flow stop components suitable for use in the present invention include a clamp (for example, a roll clamp or a pinch clamp), a stopcock, a valve or a septum. Aseptic reflex valve  310  is described, for example, in U.S. Pat. No. 5,439,451, the disclosure of which is incorporated herein by reference. In general, aseptic cleaning of connector or valve  310  is facilitated by the position of the top surface of valve member  312  relative to outlet surface  314 . In that regard, the top surface of a sealing member such as pin valve member  312  is biased outward to be preferably flush with or to extend outwardly from surface  314 . A material carrying a disinfectant (for example, a cotton ball) can easily clean the entire surface of pin valve member  312 . Moreover, valve member  314  is normally in a closed/sealed state (valve member  312  is biased outward until contacted by a male luer member), the interior of valve  310  is substantially protected from contamination from any source in the surrounding environment (whether airborne or via fluid or other contact). 
   Valve  310  is attached to tubing  320  having at least a portion thereof (for example, between markers  322  and  324 ) fabricated or designed (for example, having an appropriate inner diameter, outer diameter, durometer etc.) as known in the art for use with MR infusion pump  200 . At the end of tubing  320  opposite valve  310 , a male luer connector  360  is attached to tubing  320 . Male luer connector  360  is preferably removably attached to a flow stop component (for example, a second aseptic reflex valve  370 ). A cap  380  can be used to prevent contamination of aseptic reflex valve  370 . 
     FIG. 3B  illustrates an alternative embodiment of a tubing set for use in the present invention. Tubing set  300   a  of  FIG. 3B  includes an aseptic reflex valve  310   a  as described above. Attached to valve  310   a  is a length of tubing  320   a . As described above, at least a portion of tubing  320   a  (for example, between markers  322   a  and  324   a , is designed as known in the art for use with MR infusion pump  200 . Unlike tubing set  300 , tubing set  300   a  includes a Y-connector  340   a  including, for example, a reflex valve connector  342   a  to which, for example, another fluid source (such as manual syringe or another infusion pump/fluid source combination) can be connected. The port of Y-connector  340   a  including reflex valve connector  342   a  is preferably in a normally closed position (that is, the port is closed until coupled with a male luer connector) to prevent backflow. A protective cap  344   a  can be used to protect a female luer fitting of reflex valve connector  342   a  and the associated port of Y-connector  340   a  from contamination. Y-connector  340  can, for example be connected to tubing  320   a  via a one-way check valve  330   a  such as the Burron Check Valve No. S5402010. Y-connector  340   a  is also attached to a second length of tubing  350   a . A male luer connector  360   a  is connected to the end of tubing  350   a  opposite the end attached to Y-connector  340   a . Male luer connector  350  is preferably attached to a second aseptic reflex valve  370   a . A cap  380   a  can be used to prevent contamination of aseptic reflex valve  370   a . Tubing set  300   a  can, for example, be attached to a bag spike  400   a  via a standard luer connector  390   a.    
   Tubing set  300  and/or  300   a  can include encoding (for example, electrical, mechanical and/or optical encoding) to communicate information to, for example, infusion pump  200 . Such information can, for example, include priming volume, tubing length, pressure rating, flow rate rating, durometer etc. Encoding of fluid path elements is described in U.S. Pat. No. 5,739,508, the disclosure of which is incorporated herein by reference. Infusion pump  200  can, for example, be provided with sensors such as optical or other sensors that are in communication with a microprocessor in infusion pump  200 . A verification program can, for example, be provided to prevent use of tubing sets that are not properly encoded (and thus possibly not suited for use with MR infusion pump  200 ) from being used with MR infusion pump  200 . 
   Tubing sets of the present invention such as tubing sets  300  and  300   a  are preferably suited for use in an MR environment in that (i) no component of the tubing set is substantially adversely affected by the magnetic fields of the MR imaging equipment (for example, subject to excessive force or subject to excessive induced currents) and (ii) no component of the tubing set substantially adversely affects the MR image (for example, by creating excessive artifacts). For example, the materials used in the tubing sets of the present invention preferably have low magnetic susceptibility and do not undergo large attraction forces or affect magnetic field homogeneity. For example, biasing members used in connectors  310 ,  310   a ,  370  and  370   a  can be polymeric. However, use of small amount of metallic material such as spring biasing member in components such as connectors  310 ,  310   a ,  370  and  370   a  has been found to not substantially adversely effect either the operation of the connector or the MR imaging equipment. 
   The tubing sets of the present invention can also be fabricated to be nonfunctional after a single use using methods known in the art. It may be desirable to prevent reuse to, for example, reduce the risk of cross-contamination between patients. Reuse of a particular encoded tubing set with one MR infusion pump can, for example, be prevented in the programming of the infusion pump. 
     FIG. 4A  illustrates an initial step in one method of incorporating tubing set  300  or  300   a  of the present invention into a fluid delivery system originally including infusion pump  10 , tubing set  30  and extension set  90 . In that regard, tubing set  300  (or  300   a ) is preferably first removed from its packaging and cap  380  removed from valve  370 . Preferably, tubing set  370  is packaged in a sterile condition as known in the art. 
   In several embodiments, tubing set  300  (or tubing set  300   a ) is packaged in a compacted or volume-reduced form to facilitate packaging and incorporation of tubing set  300  into, for example, the fluid delivery system of  FIG. 2 . For example, tubing set  300  can be wound around a cylindrical packaging element  390   a . During the initial steps of incorporation/connection of tubing set  300   a , only the length required for connection need be removed from around packaging element  390   a , thereby preventing problems such as tangling and/or tripping that can occur upon complete unwinding. Tubing set  300  can be quite long (for example, 8 to 10 feet) in some embodiments, depending upon the distance from the MR equipment at which infusion pump  200  is preferably operated. In that regard, the degree to which MR infusion pumps suitably or desirably operate within the MR environment can vary between pumps and it may be desirable to maintain some distance between the MR infusion pump and the MR equipment to prevent failure of the MR infusion pump, undesirably large forces on the pump or image artifacts.  FIG. 4B  illustrates another packaging element  390   b  in which tubing  320  is packaged in a manner similar to Christmas tree lighting. 
   As illustrated in  FIG. 5 , blood backflow from extension set  90  is preferably prevented (upon disconnection of extension set  90  from tubing set  30 ) by, for example, placing a clamp (for example, a slide clamp  120  as illustrated in  FIG. 3A ) on extension set  90 . Clamp  120  can, for example, be shipped with tubing set  300 . In one embodiment, cap  380  and clamp  120  were formed integrally. As illustrated in  FIG. 6 , after clamping extension set  90  (that is, preventing backflow therefrom), extension set  90  is disconnected form tubing set  30 . After disconnection of extension set  90 , tubing set  300  is attached to tubing set  30  via connection of valve  310  and male luer connector  80  as illustrated in  FIG. 7 . At this time, infusion pump  10  can be used to prime the fluid path as known in the art (that is, to displace gas or other fluid within the fluid path with the injection fluid), including tubing set  300 , by forcing fluid from IV bag  110 . 
   If tubing  60  does not allow flow therethrough (for example, free flow via gravity) without infusion pump  10  being in operative connection with tubing  60 , it may be necessary to, for example, remove tubing set  30  and respike IV bag  110  with a spike connected to tubing set  300  or  300   a  or to provide another source of fluid. However, the system of the present invention can also include a flow element such as free flow element or adapter  210  shown attached to infusion pump  200  in  FIG. 3A  which is attachable to tubing  60 , in a similar fashion, to pump  10 , to cause free flow therethrough. In that regard, free flow element  210  preferably includes a mechanism or key operable in the same or similar manner as the mechanism of pump  10 , which allows free flow through tubing  60 . 
   As illustrated in  FIG. 8 , MR infusion pump  200  is then preferably placed in operative connection with tubing set  300  as known in the art. At this point, infusion pump  10  can be disconnected and removed from tubing set  30  as illustrated in  FIG. 9 . If priming of the fluid path has not been accomplished with infusion pump  10 , infusion pump  200  can now be used to prime the fluid path. Extension set  90  can now be connected to tubing set  300  via valve  370  and luer connector  92  as illustrated in  FIG. 10 . At this point, infusion pump  200  is in operative connection between IV bag  110  and catheter  100 . 
   Once infusion in the MR environment is complete or at some later time, extension set  90  can be disconnected from tubing set  300  by disconnecting male luer  350  from valve  370 . As illustrated in  FIG. 11 , valve  370  (or other flow stop component) is preferably maintained in connection with extension set  90  to prevent backflow of blood and to enable subsequent airless, aseptic reconnection to tubing set  30 . A clamp such as clamp  120  can also, for example, be reinstalled on extension set  90  to prevent backflow of blood. As illustrated in  FIG. 12 , infusion pump  10  can now be reconnected to tubing set  30 . Infusion pump  200  can be disconnected from tubing set  300  and tubing set  300  disconnected from luer connector  80  as illustrated in  FIG. 13 . At this point, an operator can wipe the valve member of valve  370  with, for example, a material carrying a disinfectant (for example, a cotton ball) to easily clean/disinfect the entire surface of the valve member. As illustrated in  FIG. 14 , tubing set  60  can now be reconnected to extension set  90  by connection of luer connector  80  and valve member  370 . At this point, infusion pump  10  is ready to pump fluid from IV bag  110 . 
   In many cases it may be desirable to remove MR infusion pump  200  from the fluid path immediately after the MR procedure is completed. For example, MR infusion pump  200  may be of limited functionality compared to infusion pump  10 , there may be a limited supply of MR infusion pumps  200  at a facility, or operator familiarity with the operation of MR infusion pump  200  may be limited as compared to operator familiarity with the operation of infusion pump  10 . 
   In removing tubing set  300  from the fluid path as described above, some injection fluid is going to be removed from the fluid path (that is, an amount generally equal to the volume of tubing  300 ). It may be desirable, to account for such lost fluid volume in the future programmed delivery of the injection fluid to the patient. In general, it may be desirable to provide for communication/accumulation of information regarding, for example, the amount of fluid delivered by pump  10  and the amount of fluid delivered by pump  200 . This can be accomplished, for example, by direct communication between pump  10  and pump  200  (via, for example, an Ethernet network or direct cable connection) or through operator assisted communication. For example, an operator can write the volume injected, flow rate etc. for MR infusion pump  200  during its operation and transfer that information to pump  10  when it is reconnected to the fluid path. Information can also be transferred from infusion pump  10  to infusion pump  200 . Paper labels on the pumps, a chart positioned on the IV pole or a patient chart can, for example, be used to record and transfer the information. 
   The present invention provides for simple and efficient replacement or substitution of an infusion pump or pumps with another infusion pump or pumps without, for example, discarding the tubing set provided with the initial pump(s). In the case of tubing sets having a Y-connector (for example, Y-connector port  72 ) or other port to which fluid path elements can be connected (via, for example, luer connections), a tubing set of the present invention such as tubing set  300   a  can be attached to the Y-connector via, for example, aseptic luer connector  370   a . Spike  400   a  can be used to, for example, respike IV bag  110 . Infusion pump  10  can be removed from tubing set  60  and MR infusion pump  200  connected to tubing set  300   a . Roll clamp  66  can be used to prevent backflow through tubing  60 . 
   As illustrated in  FIG. 15A , a plurality of MR infusion pumps  200   a  and  200   b  (as described above in connection with infusion pump  200 ) can be used in the present invention. For example, two infusion pumps  10  may be connected to a patient that are to be replaced by infusion pumps  200   a  and  200   b . Alternatively a multi-path or multi-channel infusion pump with two lines passing therethrough may be connected to a patient and be replaced with infusion pumps  200   a  and  200   b . In general, MR infusion pump  200   a  is connected to tubing set  300   a  and extension set  90  generally as described above in connection with infusion pump  200  and tubing set  30 . Another tubing set  300   b  is connected to female luer connector  342   a  of Y-connector  340   a . Second infusion pump  200   b  is placed in operative connection with tubing set  300   b.  A spike  400   b  connected to tubing set  300   b  is connected to an IV bag  510 . Tubing set  300   b  preferably includes a Y-connector  340   b  having a female luer connector  342   b  on one port thereof as described above in connection with tubing set  300   a . One port of Y connector  340   b  is connected to a length of tubing  350   b , which is connected female luer connector  342   a  via a standard male luer connector  360   b . In  FIG. 15B  a multi-path MR infusion pump  250  is illustrated that can be used to replace two infusion pumps  10  or another multi-path infusion pump. 
   Many configurations with multiple MR infusion pumps as described above are possible. For example,  FIG. 16  illustrates one embodiment in which four MR infusion pumps  200   a ,  200   b ,  200   c  and  200   d  are each connected to separate IV bags  110 ,  510 ,  610  and  710 , respectively. In the embodiment of  FIG. 16 , tubing set  3   00   a  includes a three-port fixture  800  in fluid connection therewith between marker  324   a  and valve  370 . Each of tubing sets  300   b ,  300   c  and  300   d  is connected to a port  810 ,  820  and  830 , respectively, (for example, via standard luer connectors) of three-port fixture  800 . In the embodiment of  FIG. 16 , tubing sets  300   c  and  300   d  are similar in configuration to tubing set  300   b  as described above. The system of  FIG. 16  can, for example, be used to replace four infusion pumps  10  or a single, four-channel infusion pump. 
   Although the present invention has been described in detail in connection with the above examples, it is to be understood that such detail is solely for that purpose and that variations can be made by those skilled in the art without departing from the spirit of the invention. The scope of the invention is indicated by the following claims rather than by the foregoing description. All changes to the present invention that fall within the meaning and range of equivalency of the claims are to be embraced within their scope.