WO2010019456A1 - Injector auto purge - Google Patents

Abstract

An auto purge protocol (380) is disclosed, and which may be used by power injector contra! logic (350) of a power injector (320). The protocol (380) may only require a single input by an operator to complete. The protocol (380) causes the injector (320) to extend a plunger (326) of a syringe (324) to a first position. Thereafter and without any operator interaction, the injector (320) is caused by the protocol (380) to extend a plunger (330) of another syringe (328) to a second position. A tubing set (332) may be fluidty interconnected with these syringes (324, 328) during the execution of this auto purge protocol (380).

Description

INJECTORAUTO PURGE

CROSS-REFERENCE TO RELATED APPLICATIONS This patent application claims priority under 35 U.S.C. §119(e) to pending U.S. Provisional Patent

Application Serial No. 61/087,682 entitled "INJECTOR AUTO PURGE" filed on 9 August 2008.

FIELD OF THE INVENTION

The present invention relates generally to injectors for injecting fluids into patients and more particularly to purging air from such injectors.

BACKGROUND in many medical environments, a medical fluid is injected into a patient during diagnosis or treatment. One example is the injection of contrast media into a patient to improve nuclear medicine, Magnetic Resonance (MR), CT, optica!, Angiographic, or Ultrasound imaging, using a powered, automatic injector.

Injectors suitable for these and similar applications typically use a relatively large volume syringe and are capable of producing relatively large flow rates and injection pressures, For this reason, injectors for such applications are typically motorized, and include a large, high mass injector motor and drive train. For ease of use, the motor and drive train are typically housed in an injection head, which is supported by a floor, wall, or ceiling- mounted arm.

The injection head is typically mounted on the arm in a pivotal manner, so that the head may be tilted upward, with the syringe tip above the remainder of the syringe, to facilitate filling the syringe with fluid, and downward, with the syringe tip below the remainder of the syringe, for injection. Tilting the head in this manner faciiitates removal of air from the syringe during filling and reduces the likelihood that air will be injected into the patient during the injection process. Nevertheless, the potential for accidentally injecting air into a patient remains a serious safety concern and, if overlooked, may be fatal in some instances.

In addition to the injection head discussed above, many injectors include a console for controlling the injector. The console typically includes programmable circuitry which can be used for automatic, programmed control of the injector, so that the operation of the injector can be made predictable and potentially synchronized with operations of other equipment such as scanners or imaging equipment.

Injector systems may also be configured with two heads. Respective syringes in each head are interconnected with tubing forming a "Y₇" or "Y-tubing," leading to a single intravenous injection site on a patient. For example, such syringes may contain a contrast media and a saline solution, and may be used in combination to prevent clotting. One particular operational routine performed by the injector system is that of purging any air from the syringe, such as air introduced during filling, and any extension tubing used therewith, This purging routine or sequence for a power injector typically includes the operator tilting the head of the injector upright and advancing the plunger so as to force any air from the syringe and extension tubing. This reduces the likelihood that air will be injected into the subject during the injection process. This manual process is typically performed by trained clinicians to ensure reasonable efforts are taken to minimize or eliminate air from being injected into a patient. It wouid be desirable to simplify the set-up sequence in power injectors so that an operator may more easily (e.g., automatically) purge air from an injector prior to injection of a medical fluid into a patient.

In many applications, it is desirable to use an injector with multiple different size syringes. For example, it may be desirable to use a smaller syringe for pediatric use than for adult use. To facilitate the use of different syringe sizes, injectors have been adapted to include memory containing parameters for multiple different size syringes and to allow an operator to enter parameters or the type of syringe. Other injectors have been adapted to receive various heads specific to different syringes and select parameters for a syringe based thereon.

Irrespective of the particular size or construction of a syringe, each syringe may trap or contain a certain amount of air or gas based on the size or construction of the syringe. For example, one size of pre-filied syringe is produced with a small, e.g., approximately 1 milliliter (ml), nitrogen bubble to facilitate sterilization. As such, it would be desirable to have an auto purge for an injector that is adaptable to a variety of injectors. Further, it would also be desirable to have an auto purge for an injector that works with pre-filied and/or empty syringes of varying sizes.

SUMMARY

A first aspect of the present invention is embodied by a power injector that utilizes first and second syringe plunger drivers. At least one motorized drive source is utilized by the power injector for the first and second syringe plunger drivers. The power injector further includes power injector control logic, which in turn includes an auto purge protocol. This auto purge protocol is configured to be executed in response to a single user input. Moreover, this auto purge protocol is configured to provide only two syringe plunger driver activations. One of the syringe plunger driver activations is a first activation of the first syringe plunger driver. Another of these syringe plunger driver activations is a second activation of the second syringe plunger driver.

A number of feature refinements and additional features are applicable to the first aspect of the present invention. These feature refinements and additional features may be used individually or in any combination. The following discussion is applicable to the first aspect, up to the start of the discussion of a second aspect of the present invention. Each of the first and second syringe plunger drivers may be of any appropriate size, shape, configuration, and/or type. In one embodiment, each syringe plunger driver is in the form of a threaded drive screw. The first and second syringe plunger drivers may share a common motorized drive source, or each of the first and second syringe plunger drivers may have a dedicated motorized drive source. Each motorized drive source used by the power injector may be many appropriate size, shape, configuration, and/or type.

The single user input to initiate the auto purge protocol may be in the form of a purge button or the like presented on a graphical user interface for the power injector. No other user input is required for the auto purge protocol to complete a purging operation. The first activation associated with the first syringe plunger driver may be initiated in response to the single user input. The auto purge protocol may be configured to terminate operation of the first syringe plunger driver prior to initiating the second activation for the second syringe plunger driver. In one embodiment, the second activation for the second syringe plunger driver immediately follows a termination of the first activation associated with the first syringe plunger driver. In one embodiment, the first activation provides an uninterrupted or continuous operation of the first syringe plunger driver, while the second activation provides an uninterrupted operation of the second syringe plunger driver.

The first and second syringe plunger drivers may be activated for a purging operation only through execution of the auto purge protocol. For instance, the auto purge protocol may preclude an operator from manually activating one or more of the first and second syringe plunger drivers for purposes of a purging operation during the execution of the auto purge protocol. The auto purge protocol may be characterized as a programmed sequence. Once the auto purge protocol has been initiated, each signal used by the auto purge protocot may be generated by the power injector.

The first activation of the first syringe plunger driver may provide a first fluid volume discharge, while the second activation may provide a second fluid volume discharge (e.g., in relation to separate syringes associated with the first and second syringe plunger drivers). In one embodiment, the second fluid volume discharge is greater than the first fluid volume discharge, occurs after the first fluid volume discharge, or both. In one embodiment the first activation is associated with discharging about 1 mL of fluid, while the second activation is associated with discharging about 3 mL of fluid (e.g., where the second activation occurs after the first activation and in non-overlapping relation therewith).

First and second syringes having first and second syringe plungers, respectively, may be installed on the power injector. The first syringe plunger driver may interact with the first syringe plunger to move the same in at least one direction to discharge fluid from the first syringe. Similarly, the second syringe plunger driver may interact with the second syringe plunger to move the same in at least one direction to discharge fluid from the second syringe. The first activation from the auto purge protocol may advance the first syringe plunger for purposes of discharging fluid from the first syringe, while the second activation from the auto purge protocol may advance the second syringe plunger for purposes of discharging fluid from the second syringe.

A second aspect of the present invention is embodied by a method of purging air from an injection system, where this injection system includes a power injector, first and second syringes that are installed on the power injector, and a tubing set that is fluidly interconnected with each of the first and second syringes. A single user input is initiated, and a programmed sequence is executed in response to this initiation. The programmed sequence includes providing a single fluid discharge from the first syringe into the tubing set, and providing a single fluid discharge from the second syringe into the tubing set.

A third aspect of the present invention is embodied by a method of purging air from an injection system, where this injection systermncludes a power injector, first and second syringes that are installed on the power injector, and a tubing set that is fluidly interconnected with each of the first and second syringes. A single user input is initiated, and a programmed sequence is executed in response to this initiation. The programmed sequence includes providing an initial fluid discharge from the first syringe, where this fluid discharge from the first syringe at least reaches a connector of the tubing set (e.g., a Y-type connector). The programmed sequence further includes providing an initial fluid discharge from the second syringe, where this fluid discharge from the second syringe is directed past the connector and through a free end of the tubing set. A number of feature refinements and additional features are separately applicable to each of the second and third aspects of the present invention. These feature refinements and additional features may be used individually or in any combination in relation to each of the second and third aspects. The following discussion is separately applicable to each of the second and third aspects of the present invention. The initiation in the form of a single user input may include an individual activating a purge button or the like that is presented on a graphical user interface. This graphical user interface could be on a remotely located console ("remote" in relation to the location of the power injector), or could be incorporated on a powerhead of the power injector. Initiating a single user input means that the programmed sequence accommodates only one user input.

The fluid discharges from the first and second syringes provided by the execution of the programmed sequence may be undertaken in non-overlapping relation, without interruption or on a continuous basis, or both (e.g., a first fluid discharge from the first syringe is not the result of spaced-in-time fluid discharges from the first syringe; a second fluid discharge from the second syringe is not the result of spaced-in-time fluid discharges from the second syringe). In one embodiment, the fluid discharge from the first syringe pursuant to the execution of the programmed sequence occurs before the fluid discharge from the second syringe pursuant to the execution of the programmed sequence. In one embodiment, the fluid discharge from the second syringe is initiated in response to a termination of the fluid discharge from the first syringe.

The fluid discharge from the first syringe pursuant to the execution of the programmed sequence is less than an entire fluid volume that is initially contained within the first syringe, while the fluid discharge from the second syringe pursuant to the execution of the programmed sequence is less than an entire fluid volume that is initially contained within the second syringe. Therefore, fluid will be available in each of the first and second syringes after the purging operation has been completed for execution of at least one injection protocol.

The fluid discharge from the first syringe pursuant to the execution of the programmed sequence may be of a first fluid volume, while the fluid discharge from the second syringe pursuant to the execution of the programmed sequence may be of a second fluid volume. In one embodiment, the first and second fluid volumes are different. In one embodiment, the first fluid volume is less than the second fluid volume, including where fluid is discharged from the first syringe pursuant to the execution of the programmed sequence prior to fluid being discharged from the second syringe pursuant to the execution of the programmed sequence. In one embodiment, the first fluid volume is about 1 mL, and the second fluid volume is about 3 mL Other discharge volumes may be appropriate.

A number of feature refinements and additional features are separately applicable to each of above-noted first, second, and third aspects of the present invention. These feature refinements and additional features may be used individually or in any combination in relation to each of the above-noted first, second, and third aspects of the present invention. Any feature of any other various aspects of the present invention that is intended to be limited to a "singular" context or the like will be clearly set forth herein by terms such as "only," "single," "limited to," or the like. Merely introducing a feature in accordance with commonly accepted antecedent basis practice does not limit the corresponding feature to the singular (e.g., indicating that a power injector includes "a syringe" alone does not mean that the power injector includes only a single syringe). Moreover, any failure to use phrases such as "at least one" also does not limit the corresponding feature to the singular (e.g., indicating that a power injector includes "a syringe" alone does not mean that the power injector includes only a single syringe). Finally, use of the phrase "at least generally" or the like in relation to a particular feature encompasses the corresponding characteristic and insubstantial variations thereof (e.g., indicating that a syringe barrel is at least generally cylindrical encompasses the syringe barrel being cylindrical). Any "logic" that may be utilized by any of the various aspects of the present invention may be implemented in any appropriate manner, including without limitation in any appropriate software, firmware, or hardware, using one or more platforms, using one or more processors, using memory of any appropriate type, using any single computer of any appropriate type or a multiple computers of arty appropriate type and interconnected in any appropriate manner, or any combination thereof. This logic may be implemented at any single location or at multiple iocatioπs that are interconnected in any appropriate manner (e.g., via any type of network).

The power injector that may be utilized to provide a fluid discharge may be of any appropriate size, shape, configuration, and/or type. Any such power injector may utilize two or more syringe plunger drivers of any appropriate size, shape, configuration, and/or type, where each such syringe plunger driver is capable of at least bi-directional movement (e.g., a movement in a first direction for discharging fluid; a movement in a second direction for accommodating a loading of fluid or so as to return to a position for a subsequent fluid discharge operation), and where each such syringe plunger driver may interact with its corresponding syringe plunger in any appropriate manner (e.g., by mechanical contact; by sn appropriate coupling (mechanical or otherwise)) so as to be able to advance the syringe plunger in at least one direction (e.g., to discharge fluid). Each syringe plunger driver may utilize one or more drive sources of any appropriate size, shape, configuration, and/or type. Multiple drive source outputs may be combined in any appropriate manner to advance a single syringe plunger at a given time. One or more drive sources may be dedicated to a single syringe piunger driver, one or more drive sources may be associated with multiple syringe piunger drivers (e.g., incorporating a transmission of sorts to change the output from one syringe plunger to another syringe plunger), or a combination thereof. Representative drive source forms include a brushed or brushless electric motor, a hydraulic motor, a pneumatic motor, a piezoelectric motor, or a stepper motor.

The power injector may be used for any appropriate application where the delivery of one or more medical fluids is desired, including without limitation any appropriate medical application (e.g., computed tomography or CT imaging; magnetic resonance imaging or MRI; single photon emission computed tomography or SPECT imaging; positron emission tomography or PET imaging; X-ray imaging; angiographic imaging; optical imaging; ultrasound imaging). The power injector may be used in conjunction with any component or combination of components, such as an appropriate imaging system (e.g., a CT scanner). For instance, information could be conveyed between any such power injector and one or more other components (e.g., scan delay information, injection start signal, injection rate).

Multiple syringes may be installed on or incorporated by the power injector in any appropriate manner (e.g., detachably; front-loaded; rear-Soaded; side-loaded), any appropriate medical fluid may be discharged from a given syringe of the power injector (e.g., contrast media, a radiopharmaceutical, saline, and any combination thereof), and any appropriate fluid may be discharged from a multiple syringe power injector configuration in any appropriate manner (e.g., sequentially, simultaneously), or any combination thereof. In one embodiment, fluid discharged from a syringe by operation of the power injector is directed into a conduit (e.g., medical tubing set), where this conduit is fluidly interconnected with the syringe in any appropriate manner and directs fluid to a desired location (e.g., to a catheter that is inserted into a patient, for instance for injection). Multiple syringes may discharge into a common conduit (e.g., for provision to a single injection site). In one embodiment, each syringe includes a syringe barrel and a plunger that is disposed within and movable relative to the syringe barrel. This plunger may interface with the power injector's syringe plunger drive assembly such that the syringe plunger drive assembly is able to advance the plunger in at least one direction, and possibly in two different, opposite directions.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 illustrates a perspective view of one embodiment of an injector, including a power head, a console, and a power pack (under a cover), with the syringe, pressure jacket, heater blanket and air detection module removed. Figure 2 illustrates a perspective view of the power head of the injector of Figure 1 with a pressure jacket, syringe and heater blanket mounted thereto, showing the power head display, hand-operated control, and support arm mounting in greater detail.

Figure 3 is a partial cross-sectional view of a syringe mounted in the pressure jacket with the air detection module in place, showing the internal structure of the air detection module and its interaction with the structure of the syringe tip;

Figure 4 is a view of the air detection module taken along lines 4-4 of Figure 3, with the syringe and pressure jacket removed.

Figure 5 illustrates an electrical and electro-mechanical block diagram of the power head shown in Figures 1-4. Figure 6 is a flow chart for an injector auto purge routine for an injector having a single syringe.

Figure 7 is a flow chart for an injector auto purge routine for an injector including an air detector.

Figure 8 illustrates a perspective view of one embodiment of a dual head injector.

Figure 9 iliustrates a perspective view of the hand-held portion of the dual head injector of Figure 8.

Figure 10 is a flow chart for an injector auto purge routine for a dual head injector. Figure 11 is a flow chart of a routine for completing a purge using a low flow rate.

Figure 12 is a schematic of one embodiment of a power injector. Figure 13A is a perspective view of one embodiment of a portable stand-mounted, dual-head power injector.

Figure 13B is an enlarged, partially exploded, perspective view of a powerhead used by the power injector of Figure 13A. Figure 13C is a schematic of one embodiment of a syringe plunger drive assembly used by the power injector of Figure 13A.

Figure 14 is a schematic of one embodiment of an imaging system.

Figure 15 is a representative fluid interconnection between the patient and a representative dual-head power injector. Figure 16 is one embodiment of power injector control logic that may be used by a power injector.

Figure 17 is one embodiment of a patient image acquisition protocol that may be used by the imaging system of Figure 14 and using the power injector control logic of Figure 16.

Figure 18 is one embodiment of an auto purge protocol that may be used by the patient image acquisition protocol of Figure 17. Figure 19 is another embodiment of an auto purge protocol that may be used by the patient image acquisition protocol of Figure 17,

DETAILED DESCRIPTION

Referring to Figure 1 , an injector 20 in accordance with the present invention includes various functional components, such as a power head 22, a console 24 and a power pack 26 (mounted inside of a cover). A syringe 36 (shown in Figure 2) is mounted to the injector 20 in the face plate 28 of the power head 22, and the various injector controls are used to fill the syringe, e.g., user-filled syringe, with, e.g., contrast media for a nuclear medicine, Magnetic Resonance (MR), CT, optical, Angiographic, Ultrasound or other procedure, which media is then injected into a subject or patient under investigation under operator or pre-programmed control. It will be appreciated that a syringe may also be pre-filled.

The injector power head 22 includes a hand-operated movement controi lever 29 for use in controlling the movement of the internal drive motor, and a display 30 for indicating to the operator the current status and operating parameters of the injector. The console 24 includes a touch screen display 32 which may be used by the operator to remotely controi operation of the injector 20, and may also be used to specify and store programs for automatic injection by the injector 20, which can later be automatically executed by the injector upon initiation by the operator.

Power head 22 and console 24 connect through cabling (not shown) to the power pack 26. Power pack 26 includes a power supply for the injector 20, interface circuitry for communicating between the console 24 and power head 22, and further circuitry permitting connection of the injector 20 to remote units such as remote consoles, remote hand or foot control switches, or other original equipment manufacturer (OEM) remote control connections allowing, for example, the operation of injector 20 to be synchronized with the x-ray exposure of an imaging system. Power head 22, console 24 and power pack 26 are mounted to a carriage 34 which includes a support arm 35 for supporting power head 22 for easy positioning of power head 22 in the vicinity of the examination subject. Other installations are also contemplated however; for example, console 24 and power pack 26 may be placed on a table or mounted on an electronics rack in an examination room while power head 22 is supported by a ceiling, floor or wall mounted support arm.

Referring now to Figure 2, in operation, a syringe 36 and pressure jacket 38 are mounted to power head 22, so that the motor internal to power head 22 may be energized to move plunger drive ram 62, shown in Figure 1 , and plunger 37 within the barrel of syringe 36 toward and away from a discharge tip 40 of the syringe, to thereby expel fluid from the syringe 36 or fill the syringe with fluid. Pressure jacket 38 provides support to the outer walls of syringe 36 to protect the walls of syringe 36 from failure at high injection pressures. It will be appreciated, however, that the use of a pressure jacket is not germane to the principles of the present invention, which may be applied to injectors regardless of whether they include a pressure jacket. in the illustrated embodiment, syringe 36 and pressure jacket 38 are made of a clear plastic material through which the operator can view the current location of plunger 37 and any fluid or air in the syringe between plunger 37 and discharge tip 40. Accordingly, an operator may tilt power head 22 upward, fill syringe 36 from a source of fluid while visually monitoring the filling process, then connect the injector to tubing leading to (but not connected to) the patient, and expel, or purge, airfrom the tubing and syringe while visually monitoring the level of fluid in the syringe, and then once air has been expelled, tilt the injector downward, connect the tubing to the patient, and proceed to inject fluid into a subject. To facilitate this filling and purging process, and other operations that may be performed during injection of a subject, power head 22 includes the hand-operated movement control, which is in the form of the rotatable lever 29. Specifically, lever 29 is rotatable on an axis of rotation inside of power head 22. When the hand-operated control lever 29 is left in its home position, illustrated in Figures 1 and 2, no plunger motion is generated by power head 22. However, when hand-operated control lever 29 is rotated toward syringe 36, forward plunger motion is generated by power head 22, expelling fluid or air from syringe 36, Alternatively, when hand-operated control lever 29 is rotated away from syringe 36, reverse plunger motion is generated by power head 22, filling syringe 36 with fluid or air.

Purging any airfrom the syringe, and any extension tubing used therewith, is typically performed by an operator. This also reduces the likelihood that air will be injected into the subject during the injection process. This manual purging procedure is also typically performed by, and generally requires, trained clinicians to ensure reasonable efforts are taken to minimize or eliminate air from being injected into a patient.

As will be described hereinafter, the present invention provides a routine for an injector that an operator may use to automatically purge air from a syringe and/or tubing prior to injection of a medical fluid into a patient. Moreover, and in accordance with principles of the present invention, an injector auto purge routine is adaptable to a variety of injectors and works with pre-filied and/or empty, e.g., user-filled, syringes of varying sizes.

To ensure that fluid injected into a subject is maintained at approximately body temperature, a heater blanket 42 is installed abutting the exterior wall of pressure jacket 38. Heater blanket 42 includes an electrical heater which generates heat for regulating the temperature of fluid within syringe 36. Heater blanket 42 is mounted to a post 44 extending from face plate 28, holding heater blanket 42 in thermal contact with pressure jacket 38.

At the rear end of power head 22 is an indicator lamp 46 (covered by a light-diffusing cover) which indicates the status of the power head.

Referring now to Figures 3 and 4, the integral air detection system can be described. The air detection module 122 is mounted to the end of post 44, and is configured to wrap around the distal end of pressure jacket 38 and into contact with an outwardly projecting collar 124a surrounding the discharge neck of syringe 36. At the point of contact with collar 124a, the air detection module includes a light source 126 and light sensor 127. Light sensor 127 is a commercially available circuit, which includes sensor 127 and an oscillator which produces a trigger signal indicating when light source 126 should be stimulated to produce a light beam. The output of sensor 127 is a digital signal indicating whether the light beam is received by detector in response to triggering of the light source.

Figures 3 and 4 show illustrative ray traces showing the paths taken by light rays emitted from light source 126. Light source 126 includes an integral focusing lens, and collar 124a on the discharge neck of syringe 36 forms a second focusing lens. These lenses act in concert to direct light from light source 126 along path 129 toward collar 124b on the discharge neck of syringe 36. The internal shape of collar 124b forms a comer reflector, so that light impingent upon collar 124b from light source 126 is reflected toward light sensor 127.

As a result of this structure, when the neck of syringe 36 is filled with fluid, light rays emitted from light source 126 follow paths through the neck of syringe 36, which reflect and return to light sensor 127, such as path 129 illustrated in Figures 3 and 4. Accordingly, under such conditions, sensor 127 will produce a digital signal indicating receipt of light, which indicates the absence of air in the syringe neck. (The combined focal length of the lens in light source 126 and collar 124a, is longer than the distance traveled by light along path 129, i.e., longer than twice the distance between collar 124a and collar 124b.) However, when the neck of the syringe contains air or an air bubble, diffraction of light at air/fluid or air/syringe boundaries will cause light to deviate substantially from the path 129 illustrated in Figures 3 and 4. Specifically, light rays incident in the neck of syringe 36 might follow the path 130 illustrated in Figure 3, or the path 131 illustrated in Figure 4. In either circumstance, the presence of the air bubble prevents light from reflecting through the neck of the syringe from light source 126 to light detector 127, thus causing the light detector to produce a signal indicating failure to receive light, indicating that air is present in the neck of the syringe.

To ensure consistent, repeatabte results, air detection module 122 is structured to ensure solid contact between light source 126, light sensor 127 and the surface of collar 124a on syringe 36. Specifically, the air detection module 122 has a spring-metal interior skeleton 133, which is over molded with a soft flexible plastic 134. One end of spring metal skeleton 133 is mounted to post 44 by mounting screws 135 (which are accessible via voids in the plastic overmofd 134). The opposite end of skeleton 133 supports the air detector module, which includes a hard plastic molding 136 supporting the light source 126 and light sensor 127. Molding 136 includes a beveled section 137 sized to fit into a chamfer 138 at the aperture of pressure jacket 38. The interaction of beveled section 137 and chamfer 138 ensure precise positioning of light source 126 and light sensor 127 relative to pressure jacket 38.

The neck of the syringe 36 is sized with a slight interference fit, so that collar 124a contacts and slightly deflects air detection module 122 when the syringe 36 is inserted into pressure jacket 38, flexing spring skeleton 133 and resulting in a steady application force of light source 126 and light sensor 127 against collar 124a of syringe 36. This application force ensures good communication of light from source 126 into the neck of syringe 36 and from the neck of syringe 36 into light sensor 127.

Further details of exemplary hardware and software which control operation of an injector system such as that illustrated in Figures 1-4 can be found in U.S. Pat. No. 5,868,710, which is assigned to the assignee of the present invention and incorporated herein by reference in its entirety.

An injector system, such as injector 20, may include alternative methods of ascertaining syringe parameters, those syringe parameters relating either to, or including, the amount of air or gas that may be trapped or contained in a syringe and any extension tubing used therewith. For example, syringe parameters may be entered into injector 20 by a service technician. Syringe parameters may also be derived from face plate 28 particular to syringe 36, and that adapts injector 20 for use with that syringe 36. Face plate 28 may be locked or engaged in position on power head 22 using position cam lever 78 to facilitate the acquisition of such syringe parameters. Each of these alternative methods will, in turn, be described in some detail, as follows.

Referring once again to Figure 1, and as mentioned, console 24 and touch screen display 32 offer a user interface for an operator of the injector 20. Because the functionality related to maintaining injector 20 generally differs from that utilized by an operator, service personnel are typically provided an interface screen on the console different from an operator's interface screen. From this service interface screen, a technician may be offered a menu selection to add, or to modify, the stored definition of a syringe's physical characteristics.

The service technician may then provide input to the user interface via the input devices (e.g., keyboard, touch screen, etc.) that are part of the injector 20 or from other diagnostic equipment which can connect to interface ports of the injector 20. The service technician may thereby use the console 24 to reach the service user interface provided by injector 20 and select, from among a plurality of service-related choices, a routine that permits changing of the stored syringe definitions. Moreover, this particular service routine permits the technician to specify whether the intended change is creating a new syringe definition or changing an existing definition. If changing an existing definition, the technician can be presented with the names of stored syringes to aid with selecting the right definition to update.

In accordance with an aspect of the present invention, a technician may also enter information describing the amount of gas and/or air in a syringe and any extension tube used therewith. In accordance with another aspect of the invention, a technician may also enter a value associated with an equivalent volume related to the mechanical clearance between a plunger driver ram 62 and a syringe plunger 37. Also, the interface will preferably provide an opportunity for the service technician to label, or otherwise designate, the new syringe information. Doing so will allow an operator to more easily select the correct syringe when operating the injector. Further details of the wide variety of protocols and routines which an injector system can automatically perform using stored syringe definitions and related parameters can be found in U.S. Pat. No. 5,662,612, which is assigned to the assignee of the present invention and incorporated herein by reference in its entirety. Moreover, syringe parameters associated with the amount of gas and/or air in a syringe and any extension tube used therewith, as well as any equivalent volume related to the mechanical clearance between a plunger drive ram and a syringe plunger may also be entered.

As mentioned, syringe parameters may also be derived from face plate 28 particular to syringe 36, and that adapts injector 20 for use with that syringe 36. Again, face plate 28 may be locked or engaged in position on power head 22 using position cam lever 78 to facilitate the acquisition of such syringe parameters. Referring now to Figure 5, an electrical and electro-mechanical block diagram of the power head 22 shown in Figures 1-4 is shown. Power head 22 comprises a circuit board 48 including a microprocessor to perform communications with power pack 26. Circuit board 48 receives and/or forwards input or "touches" from touch screen 32 on console 24, and, thus, circuit board 48 including its microprocessor may receive syringe parameters as described above. Circuit board 48 also detects the output of two Hall Effect sensors 52, 54. As described, power head 22 has a removable face plate 28, shown in Figures 1 and 2. There may be multiple face plates having differently- sized apertures for accepting differently-sized syringes. Thus, although face plate 28 need not be removed to replace syringe 36 with another like sized syringe, face plate 28 may be removed to used a different sized syringe. Circuit board 48 also receives electrical pulses indicating movements from lever 29 mounted atop power head 22 and lights and extinguishes light 46 mounted at the rear of power head 22. Circuit board 48 also controls a motor 50 coupled to a gear box that translates the rotary motion of the motor to linear translation of plunger drive ram 62 and plunger 37 of syringe 36. Circuit board 48 controls heater blanket 42 which heats a contrast fluid in the syringe. Further, circuit board 48 detects the output of air detection module 122.

Circuit board 48 may further include a single-chip accelerometer configured as a tilt sensor 58. Sensor 58, mounted to circuit board 48, is configured to produce an analog voltage indicative of the tilt of power head 22 relative to the direction of Earth gravity. Moreover, sensor 58 may be used to detect any angle power head 22 is positioned in. Thus, sensor 58 may used to detect whether discharge tip of syringe 36 is pointed up or down, and since air will generally accumulate at the discharge tip when the tip is pointed up, an auto purge routine may be configured to operate only when a discharge tip is pointed generally in an upward position. Those skilled in the art will appreciate that a mercury switch may be alternatively used to detect whether discharge tip of syringe 36 is pointed up or down. Similarly, a mechanical switch and a switch actuator may also be used. Irrespective of the type of sensor used, an auto purge routine may be configured to operate only when a discharge tip is pointed generally in an upward position.

Sensor 52 detects whether face plate 28 has been locked into position using position cam lever 78 on power head 22, and if not circuit board 48 discontinues energizing motor 50, thereby preventing any further injection procedures until such time as a face plate is locked into position. Sensor 54 detects the size of the face plate in use. Moreover, this information is forwarded to circuit board 48 including the microprocessor whereby this information is associated with syringe parameters, e.g., size and type, and is used to controlling motor 50 and any syringe coupled thereto.

Irrespective of whether syringe parameters are entered from a user interface, stored in memory, and recalled for later use in controlling a syringe plunger, or derived from a face plate adapted for use with a particular size syringe, or some combination thereof, an injector auto purge routine in accordance with principles of the present invention may be developed. Moreover, air detection may also be used in such a routine.

Before describing the programmatic flow of routine 80, shown in Figure 6, a brief description of an exemplary syringe with an associated extension tube coupled thereto wiil be provided. It is this exemplary syringe and extension tubing that will be used as a backdrop for the description of routine 80, and routines 94 and 140 in Figures 7 and 10, respectively.

Referring now to Figure 9, exemplary syringe 64 is one of many particularly sized pre-filled syringes produced with a small, e.g., approximately 1 milliliter (ml), nitrogen bubble to facilitate sterilization. Such a small nitrogen bubble is generally contained within discharge tip 66 when syringe 64 is oriented in an upright position as shown in Figure 9. Associated with and coupled to syringe 64 is extension tubing 68, Extension tubing 68 is a pragmatic consideration in reaching an injection site on a patient. Extension tube 68 is of a diameter commonly used with syringe 64 and is sixty inches (60") long. As such, extension tubing 68 contains 2.5 ml of air, A further consideration is the clearance between an injector plunger drive ram (e.g., plunger drive ram 62 shown in Figure 1) and a syringe plunger (e.g., syringe 36 plunger 37 shown in Figure 2). For syringe 64 and injector 70 (which is a hand-held head 60b, better shown in Figure 8, and will be discussed in more detail hereinafter), this is the equivalent of approximate 3 ml, Thus, the total amount of gas and/or air that desired to be purged is 6,5 ml.

Those skilled in the art will appreciate that other assumptions may be made regarding the amount of air trapped during filling of an empty syringe, due to aeration during filling the syringe, These may be based on, for example, the volume of the syringe and the contrast media used, Further, those skilled in the art will appreciate that assumptions may be based on historical data and/or experience, With exemplary pre-filled syringe 64 and extension tubing 68 in mind, and referring once again to Figure

6, a flow chart for an injector auto purge routine 80 for an injector having a single syringe, such as injector 20 shown in Figures 1-5, is illustrated, As will be appreciated by one of ordinary skill in the art having the benefit of the instant disclosure, an injector generally operates under the control of a processor, and executes or otherwise reϋes upon various computer software, components, programs, objects, modules, data structures, etc. Moreover, various applications, components, programs, objects, modules, data structures, etc. may also execute on one or more processors in an injector, i.e., the processing required to implement various functions of a routine may be allocated to multiple processors within the injector.

In general, the routines executed to implement the embodiments of the present invention, whether implemented as part of an operating system or a specific application, component, program, module, or sequence of instructions, or even a subset thereof, will be referred to herein as a program or "routine," A routine typically comprises one or more instructions that are resident at various times in memory and storage devices in an injector, and that, when read and executed by one or more processors in an injector, causes the injector to perform the various steps necessary to execute steps or elements embodying the various aspect of the invention. Moreover, while the invention has and hereinafter will be described in the context of fully functioning injectors, those skilled in the art will appreciate that the various embodiments of the invention are capable of being distributed as a program product in a variety of forms, and that the invention applies equally regardless of the particular type of signal bearing media used to actually carry out the distribution. Examples of signal bearing media include, but are not limited to, recordable type media such as volatile and non-volatile memory devices, floppy and removable disks, hard disk drives, magnetic tape, optical disks (e g., CD-ROMs, DVDs, etc.), among others, and transmission type media such as digital and analog communications.

In addition, various routines described hereinafter may be identified based upon the application within which it is implemented in a specific embodiment of the invention. However, it should be appreciated that any particular program or routine nomenclature that follows is used merely for convenience, and thus the invention should not be limited to use solely in any specific routine identified and/or implied by such nomenclature. Furthermore, given the typically endless number of manners in which program functionality may be organized into routines, procedures, methods, modules, objects, and the like, as well as the various manners in which program functionality may be allocated among various software layers that are resident within a typical injector, it should be appreciated that the invention is not limited to a specific organization and allocation of routine functionality described herein.

Those skilled in the art will recognize that the exemplary routine illustrated in Figure 6 is not intended to limit the present invention, indeed, those skilled in the art will recognize that other alternative hardware and/or software environments may be used without departing from the spirit of the present invention.

Auto purge routine 80 begins execution in step 82. In step 82, the syringe size and type is determined, for example, using hall effect sensor 54. Pre-filled syringes are commonly available in sizes including 50, 75, 100 and 125 milliliters (mL), whereas empty or user-filled syringes may be available in sizes up to, and including, 200 ml If it is determined that the syringe must be user-fllied, execution proceeds to step 84, wherein the user is prompted to fill the syringe, and whereafter execution proceeds to step 86, However, if instead, it is determined that the syringe is pre-filled, execution proceeds immediately to step 86, and the user is prompted to press or activate a purge button,

As shown in step 88, once the purge button is pressed, a plunger drive ram, such as plunger drive ram 62, moves to a predetermined stop point based on the syringe parameters determined or gathered in step 82, forcing air and/or gas from the syringe, e g , syringe 36. In step 90, the user completes the purge sequence, such as by articulating lever 29 to force any remaining air and/or gas from syringe 36 Finally, in step 92, the injector is enabled, and the user may proceed with injecting a medical fluid into a patient

Thus, auto purge routine 80 simplifies the set-up sequence in power injectors so that an operator may automatically purge air and/or gas from an injector prior to injection of a medical fluid into a patient. Moreover, auto purge routine 80 for an injector is adaptable to a variety of injectors, and works with pre-filled and/or empty syringes of varying sizes. In an alternative embodiment of the invention, the completion of the purge sequence in step 90 may involve additional program steps as will be elaborated below with reference to Figure 11.

Referring now to Figure 7, a flow chart for an injector auto purge routine 94 for an injector including an air detector is illustrated. More specifically, routine 94 is for use with user-filled syringes, though those of skill in the art may readily adapt routine 94 for use with pre-filled syringes.

Routine 94 begins execution in step 96, wherein a user fills a syringe with a medical fluid. Next, in step 98, the user is prompted to press or activate a purge button. As shown in step 100, and once the purge button is pressed, a plunger drive ram, such as plunger drive ram 62, advances or moves until an air detector, such as air detection module 122, senses fluid, and then continues for a predetermined amount, forcing any and/or gas from the syringe. Such a predetermined amount, and an associated stop position, may be based on an assumed extension tubing size. Exemplary extension tubing is shown in Figures 8 and 9 and discussed in more detail hereinafter.

Next, in step 102, the user completes the purge sequence, again, such as by articulating lever 29 to force any remaining air and/or gas from syringe 36. Finally, in step 104, the injector is enabled, and the user may proceed with injecting the medical fluid into a patient.

In an alternative embodiment of the invention, the completion of the purge sequence in step 102 may involve additional program steps as will be elaborated below with reference to Figure 11.

Thus, auto purge routine 94 simplifies the set-up sequence in power injectors so that an operator may automatically purge air and/or gas from an injector prior to injection of a medical fluid into a patient. Moreover, auto purge routine 80 for an injector is adaptable to a variety of injectors, and works with empty or user-filled syringes of varying sizes.

Those skilled in the art will also recognize that the exemplary routine illustrated in Figure 7 is also not intended to limit the present invention. Indeed, those skilled in the art will recognize that other alternative hardware and/or software environments may be used without departing from the spirit of the present invention. Referring now to Figure 8, a perspective view of a dual head injector 60 is illustrated. Dual head injector

60 comprises a mounted head 60a and a retractable or hand-held head 60b. Mounted head 60a and hand-held head 60b are configured to receive syringes 106, 108, respectively. The ram of hand-held head 60b is actuated by a purge/retract trigger that moves the ram proportionally to the amount that the trigger is depressed. Dual head injector 60 may be configured to purge air and/or gas from respective syringes 106, 108 and "Y-tubing" 110, mounted head 60a and hand-held head 60b being in electronic communication with one another.

Y-tubing 110 comprises three sections of tubing 110a-c and connector 110d. Tubing sections 110a and 110b are coupled to syringes 106 and 108, respectively, and connector 110d. Tubing section 110c is also coupled to connector 110d and typically provides connectivity with a patient injection site (not shown).

Dual head injector 60 is configured to purge the air from Y-tubing 110 in a manner similar to that described above. For example, head 60a may contain a contrast media, while hand-held head 60b may contain a saline solution for use therewith. In such case, head 60a first purges air from tubing 110a up to the intersection of Y-tubing 110 at connector 110d. Hand-held head 60b then purges the remaining air from tubing 110b, connector 11OcI, and tubing 110c, thereby substantially purging all air and/or gas from injector 60 The sequencing of purging is controlled though electronic communication of mounted head 60a and hand-held head 60b as will be appreciated by those of skill in the art

Those skilled in the art will appreciate that filling the tubing with saline has several advantages First, the saiiπe may be used to keep venous access to a subject patient clear of blood ciots Second, the saline may be used as a test injection to check for extravasation Third, the saline may help to compact the medical fluid, such as a contrast media, keeping the contrast media together

Referring now to Figure 10₁ a flow chart for injector auto purge routine 140 for a dual head injector is illustrated For example, auto purge routine 140 may be used with dual head injector 60 shown in Figure 8 head 60a containing a contrast media and being referred to as the syringe that will be injected second, or the second syringe, and hand-held head 60b containing a saline solution and being referred to as the syringe that will be injected first, or the first syringe

Auto purge routine 140 begins execution in step 142 wherein the syringe sizes and types, e g , syringes 106, 108, are determined Again, pre-fiiled syringes are commonly available in sizes including 50, 75, 100 and 125 mL, whereas empty or user-filled syringes may be available in sizes up to, and including, 200 mL If it is determined that one or both of the syringes must be user-filled, execution proceeds to step 144, wherein a user is prompted to fill the syringes, and where after execution proceeds to step 146 However, if instead, it is determined that the syringes are pre-filled, execution proceeds immediately to step 146, and the user is prompted to press or activate a purge button In step 148, once the purge button is pressed, a plunger drive ram for the syringe that is to be injected second (e g , head 60a and syringe 106) moves to a predetermined stop point based on the syringe parameters determined or gathered in step 142, forcing air and/or gas from the syringe and the tubing connected thereto, or tubing 110a In step 150, the user manually completes the purge sequence for the second syringe using a manual knob or expel buttons, forcing any remaining air and/or gas from syringe 106 and tubing 110a, up to the intersection of Y tubing 110 in connector 110d

Next, in step 152, the user is again prompted to press or activate the purge button In step 154, and once the purge button is pressed, a plunger drive ram for the syringe that is to injected first, e g , head 60b and syringe 108, moves to a predetermined stop point based on the syringe parameters determined or gathered in step 142, forcing air and/or gas from the syringe and the tubing connected thereto, or tubing 110b, connector 110d, and tubing 110c In step 156, the user manually completes the purge sequence for the first syringe using a manual knob or expel buttons, forcing any remaining air and/or gas from syringe 108 and tubing 110b, connector 110d, and tubing 110c

Finally, in step 158, the injector is enabled, and the user may proceed with injecting the medical fluid, or contrast media, and/or the saline solution into a patient In an alternative embodiment of the invention, the completion of the purge sequence in step 156 may involve additional program steps as will be elaborated below with reference to Figure 11 Thus, auto purge routine 140 simplifies the set-up sequence in power injectors so that an operator may automatically purge air and/or gas from an injector prior to injection of a medical fluid into a patient. Moreover, auto purge routine 140 is for a dual head injector, and is adaptable to a variety of injectors, working with pre-filled and/or empty syringes of varying sizes. Referring now to Figure 11 , an alternative embodiment of the invention for completing a purge sequence is illustrated. As noted above, in steps 90, 102 and 156 of Figs. 6, 7 and 10, respectively, the user completes the purge sequence after the injector automatically purges to a predetermined stop point, which is typically short of a completely expelled position. The user may expel the remaining air from the syringe under manual control, or may initiate automatic expelling movement of the ram, and then manually stop that movement when air has been completely purged A difficulty with either approach is that the speed of motion that is automatically or manually created may be excessive. For example, a typical purge flow rate of 8 ml/sec will create rapid fluid movement in the tubing and syringe extension - a rate of only 0.5 ml/sec will translate to fluid movement of 10 inches/second in tubing The user wishes to end purging flow after the fluid boundary is less than an inch past the end of the tubing, which implies that the user must have a reaction time of less than a second at typical purging flow rates. Even when using a manual movement control such as described above, it is difficult to control flow rates to the low level required for accurate purging of the fluid boundary to within an inch of a desired location.

Accordingly, in an embodiment of the present invention, the user is provided a feature for accurate low flow rate purging as the last step of a purging routine. Specifically, in an embodiment using an adjustable manual movement control such as control 29 shown in Fig. 1 , when the injector reaches step 90, 102 or 156, the injector then enables a low flow rate range for the manual movement control, e.g., with a maximum flow rate of 1 ml/sec. Then in step 162, the user uses the manual control to purge the remaining air from the tubing using the manual control operating in this low flow rate range, which watching for the moment when the fluid just fills the connecting tubing. Finally, in step 164, the user ends the manual flow by returning the manual control to a "stop" position when the tubing is full Thereafter, the injector is enabled in step 92, 104 or 158 and the injector disables the low flow rate range for the manual movement control in an alternate embodiment of the present invention, when the purge sequence is completed in step 90, 102 or 156, in step 166 the injector enables (and/or the user is prompted to initiate or initiates manually) a low flow rate purging operation, in which fluid is purged at a steady slow flow rate of, e.g , 0.5 ml/sec. While the injector continues this manual purging in step 168 the user watches for the moment when the fluid just fills the connecting tubing. Finally, in step 170, the user stops the purge flow, e.g., by depressing a button or actuating another control on the injector, when the tubing is full Thereafter, the injector is enabled in step 92, 104 or 158 and the injector continues normal operation.

The inclusion of a low flow rate completion step as described may substantially enhance the usability of an injector and improve the purging of fluid and reduce associated waste and spillage of fluid. While the present invention has been illustrated by description of various embodiments and while these embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art For example, in an injector having a tilt sensor, the routines of Figs. 6, 7 and 10 may be enhanced by including therein steps for determining whether the injector is tilted upright as a precondition to performing a purge operation, to ensure captured air is adjacent the syringe neck and discharge outlet while purging The invention in its broader aspect is, therefore, not limited to the specific details, representative system, 5 apparatus, and method, and illustrative example shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the applicant's general inventive concept.

Figure 12 presents a schematic of one embodiment of a power injector 210 having a powerhead 212. One or more graphical user interfaces or GUIs 211 may be associated with the powerhead 212. Each GU! 211 : 1) may be of any appropriate size, shape, configuration, and/or type; 2) may be operatively interconnected with the

I O powerhead 212 in any appropriate manner, 3) may be disposed at any appropriate location; 4) may be configured to provide one or any combination of the following functions: controlling one or more aspects of the operation of the power injector 210; inputting/editing one or more parameters associated with the operation of the power injector 210; and displaying appropriate information (e.g., associated with the operation of the power injector 210); or 5) any combination of the foregoing. Any appropriate number of GUIs 211 may be utilized. In one embodiment,

15 the power injector 210 includes a GUI 211 that is incorporated by a console that is separate from but which communicates with the powerhead 212. In another embodiment, the power injector 210 includes a GUI 211 that is part of the powerhead 212 In yet another embodiment, the power injector 210 utilizes one GUI 211 on a separate console that communicates with the powerhead 212, and also utilizes another GUI 211 that is on the powerhead 212 Each GUI 211 could provide the same functionality or set of functionalities, or the GUIs 211 may differ in at

20 least some respect in relation to their respective functionalities.

A syringe 228 may be installed on this powerhead 212 and, when installed, may be considered to be part of the power injector 210. Some injection procedures may result in a relatively high pressure being generated within the syringe 228. In this regard, it may be desirable to dispose the syringe 228 within a pressure jacket 226. The pressure jacket 226 is typically associated with the powerhead 212 in a manner that allows the syringe 228 to

25 be disposed therein as a part of or after installing the syringe 228 on the powerhead 212. The same pressure jacket 226 will typically remain associated with the powerhead 212, as various syringes 228 are positioned within and removed from the pressure jacket 226 for multiple injection procedures. The power injector 210 may eliminate the pressure jacket 226 if the power injector 210 is configured/utilized for low-pressure injections and/or if the syringe(s) 228 to be utilized with the power injector 210 is (are) of sufficient durability to withstand high-pressure

30 injections without the additional support provided by a pressure jacket 226. In any case, fluid discharged from the syringe 228 may be directed into a conduit 238 of any appropriate size, shape, configuration, and/or type, which may be fluidly interconnected with the syringe 228 m any appropriate manner, and which may direct fluid to any appropriate location (e g., to a patient).

The powerhead 212 includes a syringe plunger drive assembly or syringe plunger driver 214 that

35 interacts (e.g., interfaces) with the syringe 228 (e.g., a plunger 232 thereof) to discharge fluid from the syringe 228. This syringe plunger drive assembly 214 includes a drive source 216 (e.g., a motor of any appropriate size, shape, configuration, and/or type, optional gearing, and the like) that powers a drive output 218 (e.g., a rotatable drive screw). A ram 220 may be advanced along an appropriate path {e.g., axial) by the drive output 218. The ram 220 may include a coupler 222 for interacting or interfacing with a corresponding portion of the syringe 228 in a manner that will be discussed below.

The syringe 228 includes a plunger or piston 232 that is movabiy disposed within a syringe barrel 230 (e.g., for axial reciprocation along an axis coinciding with the double-headed arrow B). The plunger 232 may include a coupler 234. This syringe plunger coupler 234 may interact or interface with the ram coupler 222 to allow the syringe plunger drive assembly 214 to retract the syringe plunger 232 within the syringe barrel 230. The syringe plunger coupler 234 may be in the form of a shaft 236a that extends from a body of the syringe plunger 232, together with a head or button 36b. However, the syringe plunger coupler 34 may be of any appropriate size, shape, configuration, and/or type.

Generally, the syringe plunger drive assembly 214 of the power injector 210 may interact with the syringe plunger 232 of the syringe 228 in any appropriate manner (e.g., by mechanical contact; by an appropriate coupling (mechanical or otherwise)) so as to be able to move or advance the syringe plunger 232 (relative to the syringe barrel 230) in at least one direction (e.g., to discharge fluid from the corresponding syringe 228). That is, although the syringe plunger drive assembly 214 may be capable of bi-directional motion (e.g., via operation of the same drive source 216), the power injector 210 may be configured such that the operation of the syringe plunger drive assembly 214 actually moves each syringe plunger 232 being used by the power injector 210 in only one direction. However, the syringe plunger drive assembly 214 may be configured to interact with each syringe plunger 232 being used by the power injector 210 so as to be able to move each such syringe plunger 232 in each of two different directions (e.g. in different directions along a common axial path).

Retraction of the syringe plunger 232 may be utilized to accommodate a loading of fluid into the syringe barrel 230 for a subsequent injection or discharge, may be utilized to actually draw fluid into the syringe barrel 230 for a subsequent injection or discharge, or for any other appropriate purpose. Certain configurations may not require that the syringe plunger drive assembly 214 be able to retract the syringe plunger 232, in which case the ram coupler 222 and syringe plunger coupler 234 may not be desired, In this case, the syringe plunger drive assembly 214 may be retracted for purposes of executing another fluid delivery operation (e.g., after another pre- filled syringe 228 has been installed). Even when a ram coupler 222 and syringe plunger coupler 234 are utilized, it may such that these components may or may not be coupled when the ram 220 advances the syringe plunger 232 to discharge fluid from the syringe 228 (e.g., the ram 220 may simply "push on" the syringe plunger coupler 234 or directly on a proximal end of the syringe plunger 232). Any single motion or combination of motions in any appropriate dimension or combination of dimensions may be utilized to dispose the ram coupler 222 and syringe plunger coupler 234 in a coupled state or condition, to dispose the ram coupler 222 and syringe plunger coupler 234 in an un-coupled state or condition, or both.

The syringe 228 may be installed on the powerhead 212 in any appropriate manner. For instance, the syringe 228 could be configured to be installed directly on the powerhead 212. In the illustrated embodiment, a housing 224 is appropriately mounted on the powerhead 212 to provide an interface between the syringe 228 and the powerhead 212. This housing 224 may be in the form of an adapter to which one or more configurations of syringes 228 may be installed, and where at least one configuration for a syringe 228 could be installed directly on the powerhead 212 without using any such adapter, The housing 224 may also be in the form of a faceplate to which one or more configurations of syringes 228 may be installed. In this case, it may be such that a faceplate is required to install a syringe 228 on the powerhead 212 - the syringe 228 could not be installed on the powerhead 212 without the faceplate. When a pressure jacket 226 is being used, it may be installed on the powerhead 212 in the various manners discussed herein in relation to the syringe 228, and the syringe 228 will then thereafter be installed in the pressure jacket 226.

The housing 224 may be mounted on and remain in a fixed position relative to the powerhead 212 when installing a syringe 228. Another option is to movably interconnect the housing 224 and the powerhead 212 to accommodate installing a syringe 228. For instance, the housing 224 may move within a plane that contains the double-headed arrow A to provide one or more of coupled state or condition and an un-coupled state or condition between the ram coupler 222 and the syringe plunger coupler 234.

One particular power injector configuration is illustrated in Figure 13A₁ is identified by a reference numeral 240, and is at least generally in accordance with the power injector 210 of Figure 12. The power injector 240 includes a powerhead 250 that is mounted on a portable stand 248. A pair of syringes 286a, 286b for the power injector 240 is mounted on the powerhead 250. Fluid may be discharged from the syringes 286a, 286b during operation of the power injector 240.

The portable stand 248 may be of any appropriate size, shape, configuration, and/or type. Wheels, rollers, casters, or the like may be utilized to make the stand 248 portable. The powerhead 250 could be maintained in a fixed position relative to the portable stand 248. However, it may be desirable to allow the position of the powerhead 250 to be adjustable relative to the portable stand 248 in at least some manner. For instance, it may be desirable to have the powerhead 250 in one position relative to the portable stand 248 when loading fluid into one or more of the syringes 286a, 286b, and to have the powerhead 250 in a different position relative to the portable stand 248 for performance of an injection procedure. In this regard, the powerhead 250 may be movably interconnected with the portable stand 248 in any appropriate manner (e.g., such that the powerhead 250 may be pivoted through at least a certain range of motion, and thereafter maintained in the desired position).

It should be appreciated that the powerhead 250 could be supported in any appropriate manner for providing fluid. For instance, instead of being mounted on a portable structure, the powerhead 250 could be interconnected with a support assembly, that in turn is mounted to an appropriate structure (e.g., ceiling, wall, floor). Any support assembly for the powerhead 250 may be positioπally adjustable in at least some respect (e.g., by having one or more support sections that may be repositioned relative to one more other support sections), or may be maintained in a fixed position. Moreover, the powerhead 250 may be integrated with any such support assembly so as to either be maintained in a fixed position or so as to be adjustable relative the support assembly.

The powerhead 250 includes a graphical user interface or GUI 252. This GUI 252 may be configured to provide one or any combination of the following functions: controlling one or more aspects of the operation of the power injector 240; inputting/editing one or more parameters associated with the operation of the power injector 240; and displaying appropriate information (e.g., associated with the operation of the power injector 240). The power injector 240 may also include a console 242 and powerpack 246 that each may be in communication with the powerhead 250 in any appropriate manner (e.g., via one or more cables), that may be placed on a table or mounted on an electronics rack in an examination room or at any other appropriate location, or both. The powerpack 246 may include one or more of the following and in any appropriate combination: a power supply for the injector 240; interface circuitry for providing communication between the console 242 and powerhead 250; circuitry for permitting connection of the power injector 240 to remote units such as remote consoles, remote hand or foot control switches, or other original equipment manufacturer (OEM) remote control connections (e.g., to allow for the operation of power injector 240 to be synchronized with the x-ray exposure of an imaging system); and any other appropriate componentry. The console 242 may include a touch screen display 244, which in turn may provide one or more of the following functions and in any appropriate combination: allowing an operator to remotely control one or more aspects of trie operation of the power injector 240; allowing an operator to enter/edit one or more parameters associated with the operation of the power injector 240; allowing an operator to specify and store programs for automated operation of the power injector 240 (which can later be automatically executed by the power injector 240 upon initiation by the operator); and displaying any appropriate information relation to the power injector 240 and including any aspect of its operation.

Various details regarding the integration of the syringes 286a, 286b with the powerhead 250 are presented in Figure 13B. Each of the syringes 286a, 286b includes the same genera! components. The syringe 286a includes plunger or piston 290a that is movably disposed within a syringe barrel 288a. Movement of the plunger 290a along an axis 300a (Figure 13A) via operation of the powerhead 250 will discharge fluid from within a syringe barrel 288a through a nozzle 289a of the syringe 286a. An appropriate conduit (not shown) will typically be fluidly interconnected with the nozzle 289a in any appropriate manner to direct fluid to a desired location (e.g., a patient). Similarly, the syringe 286b includes plunger or piston 290b that is movably disposed within a syringe barrel 288b. Movement of the plunger 290b along an axis 300b (Figure 13A) via operation of the powerhead 250 will discharge fluid from within the syringe barrel 288b through a nozzle 289b of the syringe 286b. An appropriate conduit (not shown) will typically be fluidly interconnected with the nozzle 289b in any appropriate manner to direct fluid to a desired location (e.g., a patient).

The syringe 286a is interconnected with the powerhead 250 via an intermediate faceplate 302a. This faceplate 302a includes a cradle 304 that supports at least part of the syringe barrel 288a, and which may provide/accommodate any additional functionality or combination of functionalities. A mounting 282a is disposed on and is fixed relative to the powerhead 250 for interfacing with the faceplate 302a. A ram coupler 276 of a ram 274 (Figure 13C)₁ which are each part of a syringe plunger drive assembly or syringe plunger driver 256 (Figure 13C) for the syringe 286a, is positioned in proximity to the faceplate 302a when mounted on the powerhead 250. Details regarding the syringe plunger drive assembly 256 will be discussed in more detail below in relation to Figure 13C. Generally, the ram coupler 276 may be coupled with the syringe plunger 290a of the syringe 286a, and the ram coupler 276 and ram 274 (Figure 13C) may then be moved relative to the powerhead 250 to move the syringe plunger 290a along the axis 300a (Figure 13A). It may be such that the ram coupler 276 is engaged with, but not actually coupled to, the syringe plunger 290a when moving the syringe plunger 29Oa to discharge fluid through the nozzle 289a of the syringe 286a.

The faceplate 302a may be moved at least generally within a plane that is orthogonal to the axes 300a, 300b (associated with movement of the syringe plungers 290a, 29Ob₁ respectively, and illustrated in Figure 13A), both to mount the faceplate 302a on and remove the faceplate 302a from its mounting 282a on the powerhead 250. The faceplate 302a may be used to couple the syringe plunger 290a with its corresponding ram coupler 276 on the powerhead 250. In this regard, the faceplate 302a includes a pair of handles 306a. Generally and with the syringe 286a being initially positioned within the faceplate 302a, the handles 306a may be moved to in turn move/translate the syringe 286a at least generally within a plane that is orthogonal to the axes 300a, 300b (associated with movement of the syringe plungers 290a, 290b, respectively, and iliustrated in Figure 13A).

Moving the handles 306a to one position moves/translates the syringe 286a (relative to the faceplate 302a) in an at least generally downward direction to couple its syringe plunger 290a with its corresponding ram coupier 276. Moving the handles 306a to another position moves/translates the syringe 286a (relative to the faceplate 302a) in an at least generally upward direction to uncouple its syringe plunger 290a from its corresponding ram coupler 276.

The syringe 286b is interconnected with the powerhead 250 via an intermediate faceplate 302b A mounting 282b is disposed on and is fixed relative to the powerhead 250 for interfacing with the faceplate 302b. A ram coupler 276 of a ram 274 (Figure 13C), which are each part of a syringe plunger drive assembiy 256 for the syringe 286b, is positioned in proximity to the faceplate 302b when mounted to the powerhead 250. Details regarding the syringe plunger drive assembly 256 again will be discussed in more detail below in relation to Figure 13C. Generally, the ram coupler 276 may be coupled with the syringe plunger 290b of the syringe 286b, and the ram coupler 276 and ram 274 (Figure 13C) may be moved relative to the powerhead 250 to move the syringe plunger 290b along the axis 300b (Figure 13A). It may be such that the ram coupler 276 is engaged with, but not actually coupled to, the syringe plunger 290b when moving the syringe plunger 290b to discharge fluid through the nozzle 289b of the syringe 286b.

The faceplate 302b may be moved at least generally within a plane that is orthogonal to the axes 300a, 300b (associated with movement of the syringe plungers 290a, 290b, respectively, and illustrated in Figure 13A), both to mount the faceplate 302b on and remove the faceplate 302b from its mounting 282b on the powerhead 250. The faceplate 302b also may be used to couple the syringe plunger 290b with its corresponding ram coupier 276 on the powerhead 250. In this regard, the faceplate 302b may include a handle 306b, Generally and with the syringe 286b being initially positioned within the faceplate 302b, the syringe 286b may be rotated along its long axis 300b (Figure 13A) and relative to the faceplate 302b. This rotation may be realized by moving the handle 306b, by grasping and turning the syringe 286b, or both. In any case, this rotation moves/translates both the syringe 286b and the faceplate 302b at least generally within a plane that is orthogonal to the axes 30Oa₁ 300b (associated with movement of the syringe plungers 290a, 290b, respectively, and illustrated in Figure 13A). Rotating the syringe 286b in one direction moves/translates the syringe 286b and faceplate 302b in an at least generally downward direction to couple the syringe plunger 290b with its corresponding ram coupler 276. Rotating the syringe 286b in the opposite direction moves/translates the syringe 286b and faceplate 302b in an at least generally upward direction to uncouple its syringe plunger 290b from its corresponding ram coupler 276.

As illustrated in Figure 13B, the syringe plunger 290b includes a plunger body 292 and a syringe plunger coupler 294. This syringe plunger coupler 294 includes a shaft 298 that extends from the plunger body 292, along with a head 296 that is spaced from the plunger body 292. Each of the ram couplers 276 includes a larger slot that is positioned behind a smaller slot on the face of the ram coupler 276. The head 296 of the syringe plunger coupler 294 may be positioned within the larger slot of the ram coupler 276, and the shaft 298 of the syringe plunger coupler 294 may extend through the smaller slot on the face of the ram coupler 276 when the syringe plunger 290b and its corresponding ram coupler 276 are in a coupled state or condition. The syringe plunger 290a may include a similar syringe plunger coupler 294 for interfacing with its corresponding ram coupler 276.

The powerhead 250 is utilized to discharge fluid from the syringes 286a, 286b in the case of the power injector 240. That is, the powerhead 250 provides the motive force to discharge fluid from each of the syringes 286a, 286b. One embodiment of what may be characterized as a syringe plunger drive assembly or syringe plunger driver is illustrated in Figure 13C₁ is identified by reference numeral 256, and may be utilized by the powerhead 250 to discharge fluid from each of the syringes 286a, 286b. A separate syringe plunger drive assembly 256 may be incorporated into the powerhead 250 for each of the syringes 286a, 286b. In this regard and referring back to Figures 13A-B₁ the powerhead 250 may include hand-operated knobs 280a and 280b for use in separately controlling each of the syringe plunger drive assemblies 256.

Initially and in relation to the syringe plunger drive assembly 256 of Figure 13C, each of its individual components may be of any appropriate size, shape, configuration and/or type. The syringe plunger drive assembly 256 includes a motor 258, which has an output shaft 260. A drive gear 262 is mounted on and rotates with the output shaft 260 of the motor 258. The drive gear 262 is engaged or is at least engageable with a driven gear 264. This driven gear 264 is mounted on and rotates with a drive screw or shaft 266. The axis about which the drive screw 266 rotates is identified by reference numeral 268. One or more bearings 272 appropriately support the drive screw 266.

A carriage or ram 274 is movably mounted on the drive screw 266. Generally, rotation of the drive screw 66 in one direction axially advances the ram 274 along the drive screw 266 {and thereby along axis 268) in the direction of the corresponding syringe 286a/b, while rotation of the drive screw 266 in the opposite direction axially advances the ram 274 along the drive screw 266 (and thereby along axis 268) away from the corresponding syringe 286a/b. In this regard, the perimeter of at least part of the drive screw 266 includes helical threads 270 that interface with at least part of the ram 274. The ram 274 is also movably mounted within an appropriate bushing 278 that does not allow the ram 274 to rotate during a rotation of the drive screw 266. Therefore, the rotation of the drive screw 266 provides for an axial movement of the ram 274 in a direction determined by the rotational direction of the drive screw2 66. The ram 274 includes a coupler 276 that that may be detachably coupled with a syringe plunger coupler

294 of the syringe plunger 290a/b of the corresponding syringe 286a/b. When the ram coupler 276 and syringe plunger coupler 294 are appropriately coupled, the syringe plunger 290a/b moves along with ram 274. Figure 13C illustrates a configuration where the syringe 286a/b may be moved along its corresponding axis 300a/b without being coupled to the ram 274. When the syringe 286a/b is moved along its corresponding axis 300a/b such that the head 296 of its syringe plunger 290a/b is aligned with the ram coupler 276, but with the axes 268 still in the offset configuration of Figure 13C, the syringe 286a/b may be translated within a plane that is orthogonal to the axis 268 along which the ram 274 moves. This establishes a coupled engagement between the ram coupler 276 and the syringe plunger coupler 296 in the above-noted manner.

The power injectors 60, 210, 240 of Figures 8, 12 and 13A-C each may be used for any appropriate application, including without limitation for medical imaging applications where fluid is injected into a subject (e.g., a patient). Representative medical imaging applications for the power injectors 60, 210, 240 include without limitation computed tomography or CT imaging, magnetic resonance imaging or MRI, single photon emission computed tomography or SPECT imaging, positron emission tomography or PET imaging, X-ray imaging, angiographic imaging, optical imaging, and ultrasound imaging. The power injectors 60, 210, 240 each could be used alone or in combination with one or more other components. The power injectors 60, 210, 240 each may be operatively interconnected with one or more components, for instance so that information may be conveyed between the power injector 60, 210, 240 and one or more other components (e.g., scan delay information, injection start signal, injection rate).

Any number of syringes may be utilized by each of the power injectors 60, 210, 240, including without limitation single-head configurations (fora single syringe) and dual-head configurations (for two syringes). In the case of a multiple syringe configuration, each power injector 60, 210, 240 may discharge fluid from the various syringes in any appropriate manner and according to any timing sequence (e.g., sequential discharges from two or more syringes, simultaneous discharges from two or more syringes, or any combination thereof). Multiple syringes may discharge into a common conduit (e.g., for provision to a single injection site), or one syringe may discharge into one conduit (e.g., for provision to one injection site), while another syringe may discharge into a different conduit (e.g., for provision to a different injection site). Each such syringe utilized by each of the power injectors 60, 210, 240 may include any appropriate fluid (e.g., a medical fluid), for instance contrast media, a radiopharmaceutical, saline, and any combination thereof. Each such syringe utilized by each of the power injectors 60, 210, 240 may be installed in any appropriate manner (e.g., rear-loading configurations may be utilized; front-loading configurations may be utilized; side-loading configurations may be utilized).

One embodiment of an imaging system is illustrated in Figure 14 and is identified by reference numeral 310. The imaging system 310 includes an imaging unit 312 and a power injector 320a. The imaging unit 312 may be of any appropriate size, shape, configuration, and/or type, and its image-acquisition functionality may utilize any appropriate technology or combination of technologies.

The power injector 320a used by the imaging system 310 also may be of any appropriate size, shape, configuration, and/or type, for instance in the form of the power injectors 60, 210, 240 discussed above. In any case, the power injector 320a is fluidly interconnected with a patient 314 in any appropriate manner (e.g., via an appropriate tubing set). One or more fluids may be injected into the patient 314 for purposes of acquiring an image of the patient 314 (e.g., a "patient image") through operation of the imaging unit 312. Any appropriate patient image may be acquired by the imaging system 310.

A schematic is presented in Figure 15 of a representative fluid interconnection between the patient 314 and a representative dual-head power injector 320, for instance for use by the imaging system 310 of Figure 14 in place of the power injector 320a. The power injector 320 includes a powerhead 322. A pair of syringes 324, 328 are installed on the powerhead 322. The syringe 324 includes a plunger 326 movabiy disposed therein, while the syringe 328 includes a plunger 330 movabiy disposed therein. The plungers 326, 330 may be advanced in at least in one direction by corresponding a syringe plunger driver contained within the powerhead 322 (e.g., to provide a fluid discharge from the corresponding syringe 324, 328), all in accordance with the foregoing. An extension tube or tubing set 332 may be used to fluidly interconnect the power injector 320 with a patient 314. The tubing set 332 includes a tubing section 334 that extends from the syringe 324 to a connector 338 (e.g., a Y-type connector, and the view of which has been enlarged for clarity) of the extension tubing 332, along with a tubing section 336 that extends from the syringe 328 to the connector 338 as well. Another tubing section 340 extends from the connector 338 to a tubing end 342 (e.g., a free end of the tubing set 332). The tubing end 342 may include any appropriate connector, for instance to establish a fluid connection with another tubing set that leads to the patient 314, a catheter that is to be inserted into the patient 314, or the like. Generally, the tubing section 334 (syringe 324) defines one inlet leg to the connector 338, the tubing section 336 (syringe 328) defines another inlet leg to the connector 338, and the tubing section 340 defines an outlet leg from the connector 338. Therefore, a fluid discharge from each of the syringes 324, 328 is directed into a common connector 338 (via the tubing sections 3304, 336, respectively), and then through a common tubing section 340. The power injector 320, the syringes 324, 328, and the tubing set 332 may be collectively referred to as an injection system.

The power injector 320 of Figure 15 may utilize power injector control logic to control one or more aspects of its operation. One representative embodiment of such power injector control logic is illustrated in Figure 16 and is identified by reference numeral 350. Generally, the power injector control logic 350 may incorporate one or more modules, protocois, or the like. Each of these modules or protocols may incorporate a sequence of commands or a "programmed sequence" to execute one or more functionalities. Any appropriate way of initiating or activating each such module or protocol may be utilized, for instance in response to an input from the power injector 320, in response to an operator input (e.g., via a graphical user interface), or the like. The power injector control logic 350 of Figure 16 may include at least one syringe identification protoco! 352.

Generally, the syringe identification protocol 352 may be used by the power injector 320 to acquire at least some information regarding each syringe 324, 328 installed on the powerhead 322 (e.g., its "size," fluid-containing volume). One or more sensors may be utilized to acquire syringe information. For instance, one or more sensors may be utilized to identify the type of syringe 324, 328 being installed based upon the power injector 320 being able to identify the type of faceplate that has been installed on the powerhead 322 (e.g., faceplates 302a/302b from Figures 13A-C) and that may receive the syringes 324, 328. The syringes 324, 328 themselves could be encoded in any appropriate manner to allow the power injector 320 to identify the syringes 324, 328 at least when installed thereon, and to then acquire information regarding these syringes 324, 328. For instance, one or more RFID tags could be incorporated by the syringes 324, 328, and which could be read by one or more RFID reader antennas associated with the power injector 320.

The power injector control logic 350 may be configured to include one or more injection protocols 354. Each injection protocol 354 may utilize one or more fluids of any appropriate type (e.g., contrast media, saline), may include one or more phases, or both. Each phase may be defined as a delivery (e.g., for injection) of a predefined quantity of a predefined fluid in a predefined manner (e.g., one or more fixed flow rates, one or more variable flow rates, or a combination thereof). One or more of the injection protocols 354 may provide an exponentially decaying flow rate injection that is intended to optimize usage of contrast media, to provide a desired level/manner of enhancement of a region of interest of a patient 314 to be imaged, or both. Any appropriate number of the injection protocols 354 may be utilized by the power injector control logic 350,

Another aspect of the power injector control logic 350 is an auto purge protocol 356. Generally, an auto purge protocol 356 may be used to purge air or the like from one or both of the syringes 324, 328 on at least somewhat of an automated basis. Multiple auto purge protocols 356 could be utilized by the power injector control logic 350. Two examples of auto purge protocols will be discussed in more detail below in relation to Figures 18-19. It should be appreciated that even though only three modules or protocols have been addressed in relation to the power injector control logic 350, any appropriate module or protocol may be utilized by the power injector control logic 350 to provide any appropriate function or combination of functions.

The power injector control logic 350 may be implemented in any appropriate manner, including without limitation in any appropriate software, firmware, or hardware, using one or more platforms, using one or more processors, using memory of any appropriate type, using any single computer of any appropriate type or a multiple computers of any appropriate type and interconnected in any appropriate manner, or any combination thereof. The power injector control logic 350 may be implemented at any single location or at multiple locations that are interconnected in any appropriate manner (e.g., via any type of network), Figure 17 presents one embodiment of a patient image acquisition protocol 360 that may be utilized by the imaging system 310 of Figure 14, and which will be described in relation to the power injector 320 from Figure 15 using the power injector control logic 350 of Figure 16. The air purge protocol 356 is executed pursuant to step 362 of the patient image acquisition protocol 360. Thereafter, the patient 314 may be fluidly interconnected with the power injector 320 in accordance with step 364. It should be appreciated that appropriate medical personnel may be used to gain access to the vasculature of the patient 314,

An injection protocol 354 is executed pursuant to step 366 of the patient image acquisition protocol 360, At this time, the patient 314 should be fluidly interconnected with the power injector 320 (step 364). One or more patient images may be acquired through execution of step 368. It should be appreciated that steps 366 and 368 could be executed sequentially, or they may overlap in time to at least a certain degree. The protocol 360 may terminate pursuant to step 370.

One embodiment of an auto purge protocol 380 is illustrated in Figure 18, and may be used by the power injector control logic 350 of Figure 16 for its auto purge protocol 356. The tubing set 332 will be fluidly interconnected with each of the syringes 324, 328 (e.g., Figure 15). However, the tubing set 332 may not be fluidly interconnected with a patient 314 at this time.

The powerhead 322 of the power injector 320 may be in a "tilted up" configuration where the discharge nozzles of the syringes 324, 328 are disposed above horizontal when executing the auto purge protocol 380. Data may be acquired on the syringes 324, 328 and/or the tubing set 332. This may be done automatically by the power injector 320 (e.g., using the syringe identification protocol 352, and thereafter retrieving stored data for use by the auto purge protocol 380), through data entry operations to the power injector 320 (e.g., by an operator identifying the size of syringes 324, 328, the size of the tubing set 322, or both to the power injector control logic 350), or any combination thereof. The size of the syringes 324, 328, as well as the size of the tubing set 332, may have an impact on one or more of the steps of the auto purge protocol 380, specifically the locations where the syringe plungers 326, 330 are stopped during the execution of the auto purge protocol 380.

The movement of the syringe plungers 326, 330 to provide a purging operation may be manually initiated by an operator (e.g., by an operator engaging or activating a "purge button" on a graphical user interface of the power injector 320), This is the only operator input that may be required to execute the auto purge protocol 380. In any case (e.g., in response to a manual activation by an operator), the syringe plunger 326 may be extended to a first position through execution of step 384. After the syringe plunger 326 has been stopped at the first position by the power injector 320 (e.g., without any operator interaction with the power injector 320), the syringe plunger 330 will be extended to a second position through execution of step 386 and without any operator interaction with the power injector 320 (e.g., automatically undertaken by the power injector 320). The syringe plunger 330 is stopped at the second position by the power injector 320 (e.g., without any operator interaction with the power injector 320). The protocoi 380 then terminates through execution of step 390.

The extensions of the syringe plungers 326, 330 in the auto purge protocol 380 entail a movement of the syringe plungers 326, 330 toward their respective discharge nozzles. This displaces a certain volume of liquid from the syringes 324, 328 and directs the same into the tubing set 332. At least the extension from step 386 will result in fluid being discharged from the end 342 of the tubing set 332. This discharge may be directed anywhere that is appropriate, for instance into a waste container or the like.

The extension of step 384 provides the initial displacement of fluid from the syringes 324, 328 for purposes of the auto purge protocol 380. In one embodiment, this first extension (step 384) displaces a smaller fluid volume from the syringe 324 compared to the second extension (step 386, where fluid is then displaced from the syringe 328). In one embodiment, the extension provided by step 384 displaces about 1 ml of fluid from the syringe 324, while the extension provided by step 386 displaces about 3 ml of fluid from the syringe 328.

Another embodiment of an auto purge protocol 390 is illustrated in Figure 19, and may be used by the power injector control logic 350 of Figure 16 for its auto purge protocol 356. The powerhead 322 of the power injector 320 may be in a "tilted up" configuration for executing the auto purge protocol 390 and in accordance with the auto purge protocol 380 of Figure 18, Moreover, step 392 of the auto purge protocol 390 of Figure 19 may be in accordance with step 382 of the auto purge protocol 380 of Figure 18. The movement of the syringe plungers 326, 330 to provide an air purging operation may be manually initiated by an operator (e.g., by an operator engaging or activating a "purge button" on a graphical user interface of the power injector 320). This is the only operator input that may be required to execute the auto purge protocol 390. In any case (e.g., in response to a manual activation by an operator), the syringe plunger 326 extends to push liquid from the syringe 324 at least to the connector 338 of the tubing set 332 pursuant to step 394, including where this liquid may be pushed beyond the connector 338 and into the tubing section 340 of the tubing set 332. In one embodiment, this extension from step 384 displaces about 1 ml from the syringe 324. In any case, movement of the plunger 326 is then terminated without any operator interaction with the power injector 320 (e.g., automatically by the power injector 320). Without any operator interaction with the power injector 320 (e.g., automatically by the power injector

320), the syringe plunger 330 extends to push liquid from the syringe 328 until this liquid is directed out of the end 342 of the tubing set 332. In one embodiment, this extension displaces about 3 ml from the syringe 328. This discharge may be directed anywhere that is appropriate, for instance into a waste container or the like. In any case, movement of the plunger 330 is then terminated without any operator interaction with the power injector 320 (e.g., automatically by the power injector 320).

In summation and with regard to each of the auto purge protocols of 380 and 390 of Figures 18 and 19, respectively, a purge button or the like only needs to be activated once to initiate each of the protocols 380, 390 - only one operator interact is required specifically in relation to the purging operation. In each of the auto purge protocols 380, 390, there are only two total actuated movements of the plungers 326, 330 by the powerhead 322 of the power injector 320.

The foregoing description of the present invention has been presented for purposes of illustration and description. Furthermore, the description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commensurate with the above teachings, and skill and knowledge of the relevant art, are within the scope of the present invention. The embodiments described hereinabove are further intended to explain best modes known of practicing the invention and to enable others skilled in the art to utilize the invention in such, or other embodiments and with various modifications required by the particular aρρlication(s) or use(s) of the present invention. It is intended that the appended claims be construed to include alternative embodiments to the extent permitted by the prior art.

Claims

What is claimed is:

1. A power injector comprising: a first syringe plunger driver; a second syringe plunger driver; at least one motorized drive source associated with each of said first and second syringe plunger drivers; and power injector control logic comprising an auto purge protocol, wherein said auto purge protocol is configured to execute in response to a single user input and further is configured to provide only two syringe plunger driver activations in the form of a first activation of said first syringe plunger driver, followed by a second activation of said second syringe plunger driver.

2. The power injector of Claim 1, wherein each of said first and second syringe plunger drivers comprise a threaded drive screw.

3. The power injector of anyone of Claims 1-2, wherein said first and second syringe plunger drivers share a common motorized drive source.

4. The power injector of any one of Claims 1-2, wherein said at least one motorized drive source comprises first and second motorized drive sources, wherein said first motorized drive source is operatively interconnectable with said first syringe plunger driver, and wherein said second motorized drive source is operatively interconnectable with said second syringe plunger driver.

5. The power injector of any one of Claims 1-4, wherein said single user input comprises activating a purge button on a graphical user interface for said power injector.

6. The power injector of any one of Claims 1-5, wherein said first activation is initiated in response to said single user input.

7. The power injector of any one of Claims 1-6, wherein said auto purge protocol is configured to terminate said first syringe plunger driver prior to said second activation.

8. The power injector of any one of Claims 1 -7, wherein said second activation immediately follows a termination of said first activation.

9. The power injector of any one of Claims 1-8, wherein said first activation provides an uninterrupted operation of said first syringe plunger driver, and wherein said second activation provides an uninterrupted operation of said second syringe plunger driver.

10. The power injector many one of Claims 1-9, wherein said first and second syringe plunger drivers are activated for a purging operation only through execution said auto purge protocol.

11. The power injector of any one of Claims 1-10, wherein said auto purge protocol comprises a programmed sequence.

12. The power injector of any one of Claims 1-11, wherein said first activation provides a first fluid volume discharge, wherein said second activation provides a second fluid volume discharge, and wherein said second fluid volume discharge is greater than said first fluid volume discharge.

13. The power injector or any one of Claims 1-12, wherein said first activation is associated with discharging about 1ml of fluid, and wherein said second activation is associated with discharging about 3ml of fluid.

14. The power injector of any one of Claims 1-13, further comprising: a first syringe comprising a first syringe plunger, wherein said first syringe plunger driver interacts with said first syringe plunger to move said first syringe plunger in at least one direction to discharge fluid from said first syringe; and a second syringe comprising a second syringe plunger, wherein said second syringe plunger driver interacts with said second syringe plunger to move said second syringe plunger in at least one direction to discharge fluid from said second syringe.

15. The power injector of Claim 14, wherein said first activation advances said first syringe plunger, and wherein said second activation advances said second syringe plunger.

16. A method of purging air from an injection system comprising a power injector, first and second syringes installed on said power injector, and a tubing set fluidly interconnected with each of said first and second syringes, said method comprising the steps of: initiating a single user input; executing a programmed sequence in response to said initiating step, comprising: providing a single fluid discharge from said first syringe and into said tubing set; and providing a single fluid discharge from said second syringe and into said tubing set.

17. A method of purging air from an injection system comprising a power injector, first and second syringes installed on said power injector, and a tubing set fluidly interconnected with each of said first and second syringes, said method comprising the steps of: initiating a single user input; executing a programmed sequence in response to said initiating step, comprising: providing an initial fluid discharge from said first syringe comprising discharging a fluid from said first syringe at least to a connector of said tubing set; and providing an initial fluid discharge from said second syringe comprising discharging a fluid from said second syringe, past said connector, and out a free end of said tubing set.

18. The method of any one of Claims 16-17, wherein said initiating step comprises activating a purge button on a graphical user interface associated with said power injector.

19. The method of any one of Claim 16-18, wherein said programmed sequence accommodates only one user input in the form of said initiating step,

20. The method of any one of Claims 16-19, wherein said providing steps are executed in non- overlapping relation.

21. The method of any one of Claim 16-20, wherein said providing step for said first syringe is executed before said providing step for said second syringe.

22. The method of any one of Claims 16-21 , wherein said providing step in relation to said second syringe is initiated in response to a termination of said providing step for said first syringe.

23. The method of any one of Claims 16-22, wherein said providing step for said first syringe is executed without interruption, and wherein said providing step for said second syringe is executed without interruption.

24. The method of any one Claims 16-23, wherein said fluid discharge from said first syringe is 5 less than an entire fluid volume contained in said first syringe, and wherein said fluid discharge from said second syringe is less than an entire fluid volume contained in said second syringe.

25. The method of any one of Claims 16-24, wherein said providing step for said first syringe comprises displacing a first fluid volume from said first syringe, wherein said providing step for said second syringe comprises displacing a second fluid volume from said second syringe, and wherein said first and second fluid

] O volumes are different.

26. The method of Claim 25, wherein said first fluid volume is less than said second fluid volume,

27. The method of Claim 25, wherein said first fluid volume is about 1 mL, and wherein said second fluid volume is about 3 mL.

15 28. The method of any one of Claims 16 and 18-27, wherein said tubing set comprises a first tubing section that extends from said first syringe to a connector, a second tubing section that extends from said second syringe to said connector, and a third tubing section that extends from said connector to a free end, wherein said providing step for said first syringe comprises displacing a first fluid from said first syringe at least to said connector, and wherein said providing step for said second syringe comprises displacing a second fluid from 0 said second syringe out of said free end of said third tubing section.