WO2009114287A2

WO2009114287A2 - Syringe plunger drive train with multiple drive sources

Info

Publication number: WO2009114287A2
Application number: PCT/US2009/035370
Authority: WO
Inventors: Charles S. Neer; Frank M. Fago
Original assignee: Mallinckrodt Inc.
Priority date: 2008-03-11
Filing date: 2009-02-27
Publication date: 2009-09-17
Also published as: WO2009114287A3

Abstract

A drive train (110) for advancing a syringe plunger (132) in at least one direction is disclosed (e.g., to deliver fluid). This drive train (110) includes a first drive source (116a) and a second drive source (116b). The advancement of the syringe plunger (132) is dependent upon the output (118a) of the first drive source (116a), as well as on the output (118b) of the second drive source (116b). The sum of the outputs (118a, 118b) may be used to advance the syringe plunger (132), the differential of these outputs (118a, 118b) may be used to advance the syringe plunger (132), or each of the outputs (118a, 118b) may be made available to individually advance the syringe plunger (132).

Description

SYRINGE PLUNGER DRIVE TRAIN WITH MULTIPLE DRIVE SOURCES

RELATED APPLICATIONS This application claims priority to the following US provisional applications: provisional application serial number 61/035,526 filed on 11 March 2008 and entitled "SYRINGE PLUNGER DRIVE TRAIN WITH MULTIPLE DRIVE SOURCES"; and provisional application serial number 61/085,087 filed on 31 July 2008 and entitled "SYRINGE PLUNGER DRIVE TRAIN WITH MULTIPLE DRIVE SOURCES".

FIELD OF THE INVENTION

The present invention generally relates to the field of syringes and, more particularly, to the drive train for advancing a syringe plunger.

BACKGROUND

Various medical procedures require that one or more fluids be injected into the patient. Medical imaging procedures oftentimes involve the injection of contrast media into the patient, possibly along with saline or other fluids. Other medical procedures involve injecting one or more fluids into a patient for therapeutic purposes. Power injectors may be used for these types of applications. A power injector generally includes what is commonly referred to as a powerhead. One or more syringes may be mounted to the powerhead in various manners (e.g., detachably; rear-loading; front-loading; side-loading). Each syringe typically includes what may be characterized as a syringe plunger, piston, or the like. Each such syringe plunger is designed to interface with (e.g., contact and/or temporarily interconnect with) an appropriate syringe plunger driver that is incorporated into the powerhead, such that operation of the syringe plunger driver axialiy advances the associated syringe plunger inside and relative to a barrel of the syringe. One typical syringe plunger driver is in the form of a ram that is mounted on a threaded lead or drive screw and that interfaces with the associated syringe plunger. Rotation of the drive screw in one rotational direction advances the associated ram in one axial direction, while rotation of the drive screw in the opposite rotational direction advances the associated ram in the opposite axial direction. An electric motor may be used to rotate the drive screw, which may simultaneously advance the ram and associated syringe plunger. Some injection procedures require injection speeds as low as 0.10 milliliters per second, while some injection procedures require injection speeds as high as 40 milliliters per second. These "injection speeds" are expressed in terms of the resulting flow rate, but of course depend upon the rate at which the syringe plunger is being advanced. Operation of an electric motor at slower speeds may be problematic in terms of the feedback provided to the motor controller. For instance, the motor encoder simply will not generate many pulses at slower operationa! speeds for providing effective feedback to the motor's controller. SUMMARY

A first aspect of the present invention is embodied by a power injector that includes a syringe plunger, a first drive source, and a second drive source. The first drive source provides a first output, while the second drive source provides a second output. The rate at which the syringe plunger is advanced depends upon each of the first and second outputs.

Various refinements exist of the features noted in relation to the first aspect of the present invention. Further features may also be incorporated in the first aspect of the present invention as well. These refinements and additional features may exist individually or in any combination. The following discussion pertains to at least the first aspect, unless otherwise noted. A gearbox may be utilized by the power injector. The first drive source, the second drive source, and the syringe plunger may be characterized as being operatively interconnected with this gearbox. In one embodiment, the gearbox includes first and second gearbox inputs and a gearbox output. The first and second drive sources may drive the first and second gearbox inputs, respectively, and the syringe plunger may be driven by the gearbox output. A planetary gear system may be utilized by the power injector. The first drive source, the second drive source, and the syringe plunger may be characterized as being operatively interconnected with this planetary gear system. Different components of the planetary gear system may be driven by the first and second drive sources, while yet another component of the planetary gear system may drive the syringe plunger.

A second aspect of the present invention is embodied by a power injector that includes a syringe plunger, a first drive source, a second drive source, and a planetary gear system. The planetary gear system includes first, second, and third planetary gear system components, where the first and second planetary gear system components are inputs for the planetary gear system, and where the third planetary gear system component is an output for the planetary gear system. The first drive source drives the first planetary gear system component {an input), the second drive source drives the second planetary gear system component (an input), and the syringe plunger is driven by the third planetary gear system component (an output).

Various refinements exist of the features noted in relation to each of the above-noted first and second aspects of the present invention. Further features may also be incorporated in each of the above-noted first and second aspects of the present invention as well. These refinements and additional features may exist individually or in any combination in relation to each of the first and second aspects. That is, each of the following features that will be discussed is not required to be used with any other feature or combination of features unless otherwise specified.

The syringe plunger may be of any appropriate size, shape, configuration, and/or type. Generally, the syringe plunger is a movable structure that exerts a force on a fluid to deliver the same (e.g., to a fluid target, including for injection into the fluid target). The syringe plunger may be a component of a syringe of any appropriate size, shape, configuration, and/ortype, and when a syringe is installed on the power injector this syringe may be considered to be part of the power injector. This syringe may include a syringe barrel or other appropriate housing in which the syringe plunger may be movably disposed (e.g., axially movable relative to the syringe barrel). This syringe may be used with any appropriate power injector.

The first and second drive sources may be characterized as being part of a syringe plunger drive train that is able to advance the syringe plunger in at least one direction. This syringe plunger drive train may interact with the syringe plunger in any appropriate manner (e.g., by mechanical contact; by an appropriate coupling (mechanical or otherwise)) so as to be able to advance the syringe plunger in at least one direction (e.g., to deliver fluid). The syringe plunger may be moved along an axial path in at least a first direction by an operation of at least one of the first and second drive sources (e.g., for a fluid delivery stroke). Another option is for the syringe plunger to be moved along an axial path in both a first direction (e.g., for a fluid delivery stroke), and in a second direction that is opposite of the first direction (e.g., to retract the syringe plunger, for instance to draw fluid into or otherwise accommodate a loading of fluid into the associated syringe; to position the syringe plunger drive train for a subsequent fluid delivery stroke), both by an operation of a least one of the first and second drive sources. It should be appreciated that even for the case when the syringe plunger is advanced in only one direction by the syringe plunger drive train, the syringe plunger drive train itself may be capable of providing a bi-directional output (e.g., a movement in a first direction for delivering fluid; a movement in a second direction so as to return to a position for a subsequent fluid delivery stroke or operation).

The power injector may include a drive screw that is threaded (e.g., external threads), along with a ram that is threadably interconnected with the drive screw in any appropriate manner, that is movable along an axis coinciding with the length dimension of this drive screw, and that may interact with the syringe plunger in any appropriate manner to advance the same in at least one direction. Relative rotational motion between the drive screw and ram may cause the ram to move along an axis coinciding with a length dimension of the drive screw. This relative rotational motion may depend upon the outputs from each of the first and second drive sources. The drive screw and ram may be rotated about a common axis. Each of the drive screw and the ram may be rotated in each of first and second directions that are opposite of each other, including about a common axis. In one embodiment, the ram includes a threaded nut that is mounted on the drive screw, along with a ram body that extends from this threaded nut to interact with the syringe plunger to advance the same in at least one direction. Any way of movably interconnecting the ram with the drive screw may be utilized. In one embodiment and for the case of the first aspect, the first drive source may control a rotation of (e.g., drive) the drive screw, while the second drive source may control a rotation of (e.g., drive) the ram. Each of the first and second drive sources may be of any appropriate size, shape, configuration, and/or type, including being the same or different from each other in at least some respect. Representative forms for the first and second drive sources include a brushed or brushless electric motor, a hydraulic motor, a pneumatic motor, a piezoelectric motor, or a stepper motor. In any case, the sum of the outputs from the first and second drive sources may be used to advance the syringe plunger when the power injector is in a first configuration. A differential of the outputs from the first and second drive sources may be used to advance the syringe plunger when the power injector is in a second configuration. It also may be such that only one of the first and second drive sources is used to advance the syringe piunger when the power injector is in a third configuration (e.g., one of the first and second outputs will be "zero" in this instance). Each of the first and second drive sources may be made available to separately advance the syringe plunger in this third configuration. It should be appreciated that multiple magnitudes, multiple directions, or both may be utilized in relation to the outputs of the first and second drive sources in each of these first, second, and third configurations to provide a variety of speeds for the syringe plunger (and to thereby provide a variety of fluid delivery and/or injection rates).

The outputs of each of the first and second drive sources may be in the form of rotational outputs. Each of the first and second drive sources may be configured to provide rotational outputs in each of first and second directions that are opposite of each other (e.g., a clockwise rotational output and a counterclockwise rotational output). Various combinations of first and second rotational outputs may be utilized to advance the syringe plunger in at least one direction, including without limitation: 1) the first drive source may be configured to provide a first rotational output in a first direction, and the second drive source may be configured to provide a second rotational output in this same first direction (e.g., a sum of the first and second outputs may be used to advance the syringe plunger); 2) the first drive source may be configured to provide a first rotational output in a first direction, and the second drive source may be configured to provide a second rotational output in a second direction that is opposite of this first direction (e.g., a differential of the first and second outputs may be used to a advance the syringe plunger); 3) the first drive source may be configured to provide a first rotational output in a first direction, and the second drive source may be configured so as to not provide any rotational output (e.g., the magnitude of the second output may be "zero" in this instance); 4) the second drive source may be configured to provide a first rotational output in a first direction, and the first drive source may be configured so as to not provide any rotational output (e.g., the magnitude of the first output may be "zero" in this instance); 5) the first drive source may be configured to provide a first rotational output in a second direction, and the second drive source may be configured to provide a second rotational output in this same second direction (e.g., a sum of the first and second outputs may be used to advance the syringe plunger); 6) the first drive source may be configured to provide a first rotational output in a second direction, and the second drive source may be configured to provide a second rotational output in a first direction that is opposite of this second direction (e.g., a differential of the first and second outputs may be used to advance the syringe plunger); 7) the first drive source may be configured to provide a first rotational output in a second direction, and the second drive source may be configured so as to not provide any rotational output {e.g., the magnitude of the second output may be "zero" in this instance); and 8) the second drive source may be configured to provide a first rotational output in a second direction, and the first drive source may be configured so as to not provide any rotational output (e.g., the magnitude of the first output may be "zero" in this instance).

A planetary gear system may be utilized by the power injector. The first drive source, the second drive source, and the syringe plunger may be characterized as being operatively interconnected with this planetary gear system. In one embodiment, the planetary gear system may be characterized as including a first planetary gear system component, a second planetary gear system component, and a third planetary gear system component. Each of the first, second, and third planetary gear system components may rotate about a common axis. The first and second planetary gear system components may be inputs for the planetary gear system, while the third planetary gear system component may be an output for the planetary gear system. The first and second drive sources may drive the first and second planetary gear system components, respectively, while the syringe plunger may be driven by the third planetary gear system component. The first, second, and third planetary gear system components each may be a selected and different one of a sun gear, a planet gear carrier (e.g., a common structure on which a plurality of planet gears are freely and rotatably mounted), and a ring gear. The power injector may include a sun gear, a planet gear carrier, and a ring gear. A plurality of planet gears may be mounted on the planet gear carrier (e.g., each planet gear being freely rotatable relative to the planet gear carrier, and with the planet gear carrier being of any appropriate configuration). Each planet gear may engage each of the sun gear and the ring gear (e.g., each planet gear may engage an outer perimeter of the sun gear and an inner perimeter of the ring gear). In one embodiment, the first drive source drives the ring gear, the second drive source drives the sun gear, and the planet gear carrier drives the syringe plunger. The sun gear, the ring gear, and each of the planet gears may each include any appropriate number of gear teeth, may be of any appropriate size, or both.

A third aspect of the present invention is embodied by a method of operation for a power injector. First and second drive sources are simultaneously operated to advance a syringe plunger. Advancement of the syringe plunger in turn delivers a fluid.

Various refinements exist of the features noted in relation to the third aspect of the present invention. Further features may aiso be incorporated in the third aspect of the present invention as well. These refinements and additional features may exist individually or in any combination. The following discussion pertains to at least the third aspect, unless otherwise noted. A first component may be driven by the first drive source, a second component may be driven by the second drive source, and a motion of each of the first and second components may contribute to the advancement of the syringe plunger. In one embodiment, the first and second components are a threaded drive screw and a ram that is movably interconnected with this drive screw, respectively. In another embodiment, the first and second components are each part of a planetary gear set.

The outputs from the first and second drive sources may be summed together to advance the syringe plunger. Alternatively, a differential of the outputs from the first and second drive sources may be used to advance the syringe plunger. Once again, advancement of the syringe plunger causes fluid to be delivered. Although this fluid delivery may be used for any appropriate application, in one embodiment this fluid is delivered for injection into a patient (e.g., a biological mass of any appropriate type).

Various refinements exist of the features noted in relation to each of the above-noted first, second, and second aspects of the present invention. Further features may also be incorporated in each of the above-noted first, second, and third aspects of the present invention as well. These refinements and additional features may exist individually or in any combination in relation to each of the first, second, and aspects. That is, each of the following features that will be discussed is not required to be used with any other feature or combination of features unless otherwise specified. Fluid that is delivered by advancement of the syringe by operation of at least one of the first and second drive sources may be of any appropriate type (e.g., contrast media, saline, a radiopharmaceutical), may be used for any application or purpose, or both. In one embodiment, this fluid is used for a medical application (e.g., a medical fluid). In one embodiment this fluid is injected into a biological mass (e.g., a human patient, an animal).

The power injector may be of any appropriate size, shape, configuration, and/or type. The power injector may utilize one or more syringe plunger drive assemblies or drivers of any appropriate size, shape, configuration, 5 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 mechanica! contact; by an appropriate coupling (mechanical or otherwise)) so as to be able to advance the syringe plunger in l O at least one direction (e.g., to discharge fluid).

The power injector may be used for any appropriate application where the delivery of one or more medical fluids is desired and in any appropriate manner (e.g., via injection into a fluid target such as a patient), including without limitation any appropriate medical application (e.g., computed tomography or CT imaging; magnetic resonance imaging or MRI; SPECT imaging; PET imaging; X-ray imaging; angiographic imaging; optical

15 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).

Any appropriate number of syringes may be utilized with the power injector in any appropriate manner 0 (e.g., detachably; front-loaded; rear-loaded; side-loaded) and where the advancement of each syringe plunger may be dependent upon the output of multiple drive sources, any appropriate fluid may be discharged from a given syringe of any such 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 5 delivered from a syringe by operation of the power injector is directed into a conduit, 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), 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 different0 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 interact with the power injector's syringe plunger drive assembly or drive train such that the syringe plunger drive assembly is able to advance the syringe plunger in at least one direction, and possibly in two different, opposite directions.

There are a number of advantages associated with having multiple drive sources available to drive a5 common syringe plunger. One is that the range of outputs to the syringe plunger {e.g., the range between the minimum and maximum outputs, where the minimum output provides the minimum flow/injection rate and where the maximum output provides the maximum flow/injection rate) may be larger when using multiple drive sources compared to that which could be realized using a single drive source. In one embodiment, a first dynamic range ratio is a ratio of a maximum output of the first drive source to a minimum output of the first drive source, a second dynamic range ratio is a ratio of a maximum output of the second drive source to a minimum output of the second drive source, and a syringe plunger dynamic range ratio is a ratio of a maximum and minimum outputs to the syringe plunger, where the syringe plunger dynamic range ratio is greater than each of the first and second dynamic range ratios. In one embodiment, a first dynamic range ratio is a ratio of a maximum output of the first drive source to a minimum output of the first drive source, and a syringe plunger dynamic range ratio is a ratio of a maximum output to the syringe plunger to a minimum output to the syringe plunger, where the syringe plunger dynamic range ratio is at least 10O times greater than the first dynamic range ratio. In one embodiment, a first dynamic range ratio is a ratio of a maximum output of the first drive source to a minimum output of the first drive source, and a syringe plunger dynamic range ratio is a ratio of a maximum output to the syringe plunger to a minimum output to the syringe plunger, where the syringe plunger dynamic range ratio is at least 200 times greater than the first dynamic range ratio.

Another advantage associated with having multiple drive sources available to drive a common syringe plunger is that the total power requirements may be reduced compared to using a single drive source, including without limitation for the case of when attempting to realize comparable dynamic range ratios. Having multiple drives sources available to drive a common syringe plunger may allow the individual drive sources to be operated in a more efficient range compared to the case of using a single drive source, including without limitation for the case of when attempting to realize comparable dynamic range ratios. Enhanced and/or less cumbersome control of the speed of the individual drive sources in a multiple drive source configuration may be realized compared to using a single drive source.

BRIEF DESCRIPTION OF THE FIGURES Figure 1 is a schematic of one embodiment of a power injector. Figure 2A is a perspective view of one embodiment of a portable stand-mounted, dual-head power injector.

Figure 2B is an enlarged, partially exploded, perspective view of a powerhead used by the power injector of Figure 2A.

Figure 2C is a schematic of one embodiment of a syringe plunger drive assembly used by the power injector of Figure 2A.

Figure 3A is a schematic of one embodiment of a multiple drive source drive train for a syringe plunger. Figure 3B is a schematic of one embodiment of a selector that may be used by each of the drive sources utilized by the drive train of Figure 3A.

Figure 4A is a schematic of one embodiment of a multiple drive source drive train for a syringe plunger, where one drive source controls rotation of a drive screw and where another drive source controls rotation of a ram mounted on the drive screw. Figure 4B is a schematic of one embodiment of a multiple drive source drive train for a syringe plunger, where the drive train incorporates a gearbox.

Figure 4C is a schematic of one embodiment of a multiple drive source drive train for a syringe plunger, where the drive train incorporates a planetary gear system. Figure 4D is a schematic of one embodiment of a multiple drive source drive train for a syringe plunger, where the drive train incorporates a planetary gear system.

Figure 5 is a plan view of a planetary gear system that may be used by each of the drive trains of Figures 4C and 4D.

Figure 6 is a perspective view of one embodiment of a multiple drive source drive train for a syringe plunger, where the drive train incorporates a planetary gear system.

DETAILED DESCRIPTION

Figure 1 presents a schematic of one embodiment of a power injector 10 having a powerhead 12. One or more graphical user interfaces or GUIs 11 may be associated with the powerhead 12. Each GU1 11: 1) may be of any appropriate size, shape, configuration, and/or type; 2) may be operatively interconnected with the powerhead 12 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 10; inputting/editing one or more parameters associated with the operation of the power injector 10; and displaying appropriate information (e.g., associated with the operation of the power injector 10); or 5) any combination of the foregoing. Any appropriate number of GUIs 11 may be utilized. In one embodiment, the power injector 10 includes a GU1 11 that is incorporated by a console that is separate from but which communicates with the powerhead 12. In another embodiment, the power injector 10 includes a GU1 11 that is part of the powerhead 12. In yet another embodiment, the power injector 10 utilizes one GU! 11 on a separate console that communicates with the powerhead 12, and also utilizes another GU! 11 that is on the powerhead 12. Each GU! 11 could provide the same functionality or set of functionalities, or the GUIs 11 may differ in at least some respect in relation to their respective functionalities.

A syringe 28 may be installed on this powerhead 12 and, when installed, may be considered to be part of the power injector 10. Some injection procedures may result in a relatively high pressure being generated within the syringe 28. In this regard, it may be desirable to dispose the syringe 28 within a pressure jacket 26. The pressure jacket 26 is typically associated with the powerhead 12 in a manner that allows the syringe 28 to be disposed therein as a part of or after Installing the syringe 28 on the powerhead 12. The same pressure jacket 26 will typically remain associated with the powerhead 12, as various syringes 28 are positioned within and removed from the pressure jacket 26 for multiple injection procedures. The power injector 10 may eliminate the pressure jacket 26 if the power injector 10 is configured/utilized for low-pressure injections and/or if the syringe(s) 28 to be utilized with the power injector 10 is(are) of sufficient durability to withstand high-pressure injections without the additional support provided by a pressure jacket 26. In any case, fluid discharged from the syringe 28 may be directed into a conduit 38 of any appropriate size, shape, configuration, and/or type, which may befluidly interconnected with the syringe 28 in any appropriate manner, and which may direct fluid to any appropriate location (e.g., to a patient).

The powerhead 12 includes a syringe plunger drive assembly or syringe plunger driver 14 that interacts (e.g., interfaces) with the syringe 28 (e.g., a plunger 32 thereof) to discharge fluid from the syringe 28. This syringe plunger drive assembly 14 includes a drive source 16 (e.g., a motor of any appropriate size, shape, configuration, and/or type, optional gearing, and the like) that powers a drive output 18 (e.g., a rotatable drive screw). A ram 20 may be advanced along an appropriate path (e.g., axial) by the drive output 18. The ram 20 may include a coupler 22 for interacting or interfacing with a corresponding portion of the syringe 28 in a manner that wiil be discussed below. The syringe 28 includes a plunger or piston 32 that is movably disposed within a syringe barrel 30 (e.g., for axial reciprocation along an axis coinciding with the double-headed arrow B). The plunger 32 may include a coupler 34. This syringe plunger coupler 34 may interact or interface with the ram coupler 22 to allow the syringe plunger drive assembly 14 to retract the syringe plunger 32 within the syringe barrel 30. The syringe plunger coupler 34 may be in the form of a shaft 36a that extends from a body of the syringe plunger 32, 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 14 of the power injector 10 may interact with the syringe plunger 32 of the syringe 28 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 32 (relative to the syringe barrel 30) in at least one direction (e.g., to discharge fluid from the corresponding syringe 28). That is, although the syringe plunger drive assembly 14 may be capable of bi-directional motion (e.g., via operation of the same drive source 16), the power injector 10 may be configured such that the operation of the syringe plunger drive assembly 14 actually only moves each syringe plunger 32 being used by the power injector 10 in only one direction. However, the syringe plunger drive assembly 14 may be configured to interact with each syringe plunger 32 being used by the power injector 10 so as to be able to move each such syringe plunger 32 in each of two different directions (e.g. in different directions along a common axial path).

Retraction of the syringe plunger 32 may be utilized to accommodate a loading of fluid into the syringe barrel 30 for a subsequent injection or discharge, may be utilized to actually draw fluid into the syringe barrel 30 for a subsequent injection or discharge, or for any other appropriate purpose. Certain configurations may not require that the syringe plunger drive assembly 14 be able to retract the syringe plunger 32, in which case the ram coupler 22 and syringe plunger coupler 34 may not be desired. In this case, the syringe plunger drive assembly 14 may be retracted for purposes of executing another fluid delivery operation (e.g., after another pre-filied syringe 28 has been installed). Even when a ram coupler 22 and syringe plunger coupler 34 are utilized, it may such that these components may or may not be coupled when the ram 20 advances the syringe plunger 32 to discharge fluid from the syringe 28 (e.g., the ram 20 may simply "push on" the syringe plunger coupler 34 or on a proximal end of the syringe plunger 32). Any single motion or combination of motions in any appropriate dimension or combination of dimensions may be utilized to dispose the ram coupler 22 and syringe plunger coupler 34 in a coupled state or condition, to dispose the ram coupler 22 and syringe plunger coupler 34 in an un-coupled state or condition, or both.

The syringe 28 may be installed on the powerhead 12 in any appropriate manner. For instance, the syringe 28 could be configured to be installed directly on the powerhead 12. In the illustrated embodiment, a housing 24 is appropriately mounted on the powerhead 12 to provide an interface between the syringe 28 and the powerhead 12. This housing 24 may be in the form of an adapter to which one or more configurations of syringes 28 may be installed, and where at least one configuration for a syringe 28 could be installed directly on the powerhead 12 without using any such adapter. The housing 24 may also be in the form of a faceplate to which one or more configurations of syringes 28 may be installed. In this case, it may be such that a faceplate is required to install a syringe 28 on the powerhead 12 - the syringe 28 could not be installed on the powerhead 12 without the faceplate. When a pressure jacket 26 is being used, it may be installed on the powerhead 12 in the various manners discussed herein in relation to the syringe 28, and the syringe 28 will then thereafter be installed in the pressure jacket 26.

The housing 24 may be mounted on and remain in a fixed position relative to the powerhead 12 when installing a syringe 28. Another option is to movably interconnect the housing 24 and the powerhead 12 to accommodate installing a syringe 28. For instance, the housing 24 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 22 and the syringe plunger coupler 34.

One particular power injector configuration is illustrated in Figure 2A, is identified by a reference numeral 40, and is at least generally in accordance with the power injector 10 of Figure 1. The power injector 40 includes a powerhead 50 that is mounted on a portable stand 48. A pair of syringes 86a, 86b for the power injector 40 is mounted on the powerhead 50. Fluid may be discharged from the syringes 86a, 86b during operation of the power injector 40.

The portable stand 48 may be of any appropriate size, shape, configuration, and/or type. Wheels, rollers, casters, or the like may be utilized to make the stand 48 portable. The powerhead 50 could be maintained in a fixed position relative to the portable stand 48. However, it may be desirable to allow the position of the powerhead 50 to be adjustable relative to the portable stand 48 in at least some manner. For instance, it may be desirable to have the powerhead 50 in one position relative to the portable stand 48 when loading fluid into one or more of the syringes 86a, 86b, and to have the powerhead 50 in a different position relative to the portable stand 48 for performance of an injection procedure. In this regard, the powerhead 50 may be movably interconnected with the portable stand 48 in any appropriate manner (e.g., such that the powerhead 50 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 50 could be supported in any appropriate manner for providing fluid. For instance, instead of being mounted on a portable structure, the powerhead 50 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 50 may be positionally 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 50 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 50 includes a graphical user interface or GUI 52. This GUI 52 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 40; inputting/editing one or more parameters associated with the operation of the power injector 40; and displaying appropriate information (e.g., associated with the operation of the power injector 40). The power injector 40 may also include a console 42 and powerpack 46 that each may be in communication with the powerhead 50 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 46 may include one or more of the following and in any appropriate combination: a power supply for the injector 40; interface circuitry for providing communication between the console 42 and powerhead 50; circuitry for permitting connection of the power injector 40 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 40 to be synchronized with the x-ray exposure of an imaging system); and any other appropriate componentry. The console 42 may include a touch screen display 44, 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 the operation of the power injector 40; allowing an operator to enter/edit one or more parameters associated with the operation of the power injector 40; allowing an operator to specify and store programs for automated operation of the power injector 40 {which can later be automatically executed by the power injector 40 upon initiation by the operator); and displaying any appropriate information relation to the power injector 40 and including any aspect of its operation.

Various details regarding the integration of the syringes 86a, 86b with the powerhead 50 are presented in Figure 2B. Each of the syringes 86a, 86b includes the same general components. The syringe 86a includes plunger or piston 90a that is movably disposed within a syringe barrel 88a. Movement of the plunger 90a along an axis 100a (Figure 2A) via operation of the powerhead 50 will discharge fluid from within a syringe barrel 88a through a nozzle 89a of the syringe 86a. An appropriate conduit (not shown) will typically be fluidly interconnected with the nozzle 89a in any appropriate manner to direct fluid to a desired location (e.g., a patient). Similarly, the syringe 86b includes plunger or piston 90b that is movably disposed within a syringe barrel 88b. Movement of the plunger 90b along an axis 100b (Figure 2A) via operation of the powerhead 50 will discharge fluid from within the syringe barrel 88b through a nozzle 89b of the syringe 86b. An appropriate conduit (not shown) will typically be fluidly interconnected with the nozzle 89b in any appropriate manner to direct fluid to a desired location (e.g., a patient).

The syringe 86a is interconnected with the powerhead 50 via an intermediate faceplate 102a. This faceplate 102a includes a cradle 104 that supports at least part of the syringe barrel 88a, and which may provide/accommodate any additional functionality or combination of functionalities. A mounting 82a is disposed on and is fixed relative to the powerhead 50 for interfacing with the faceplate 102a. A ram coupler 76 of a ram 74 (Figure 2C), which are each part of a syringe plunger drive assembly or syringe plunger driver 56 (Figure 2C) for the syringe 86a, is positioned in proximity to the faceplate 102a when mounted on the powerhead 50. Details regarding the syringe plunger drive assembly 56 will be discussed in more detail below in relation to Figure 2C. Generally, the ram coupler 76 may be coupled with the syringe plunger 90a of the syringe 86a, and the ram coupler 76 and ram 74 (Figure 2C) may then be moved relative to the powerhead 50 to move the syringe plunger 90a along the axis 100a {Figure 2A). It may be such that the ram coupler 76 is engaged with, but not actually coupled to, the syringe plunger 90a when moving the syringe plunger 90a to discharge fluid through the nozzle 89a of the syringe 86a.

The faceplate 102a may be moved at least generally within a plane that is orthogonal to the axes 10Oa₁ 100b (associated with movement of the syringe plungers 90a, 90b, respectively, and illustrated in Figure 2A), both to mount the faceplate 102a on and remove the faceplate 102a from its mounting 82a on the powerhead 50. The faceplate 102a may be used to couple the syringe plunger 90a with its corresponding ram coupler 76 on the powerhead 50. In this regard, the faceplate 102a includes a pair of handles 106a. Generally and with the syringe 86a being initially positioned within the faceplate 102a, the handles 106a may be moved to in turn move/translate the syringe 86a at least generally within a plane that is orthogonal to the axes 100a, 100b (associated with movement of the syringe plungers 90a, 90b, respectively, and illustrated in Figure 2A). Moving the handles 106a to one position moves/translates the syringe 86a (relative to the faceplate 102a) in an at least generally downward direction to couple its syringe plunger 90a with its corresponding ram coupler 76. Moving the handles 106a to another position moves/translates the syringe 86a (relative to the faceplate 102a) in an at least generally upward direction to uncouple its syringe plunger 90a from its corresponding ram coupler 76. The syringe 86b is interconnected with the powerhead 50 via an intermediate faceplate 102b. A mounting

82b is disposed on and is fixed relative to the powerhead 50 for interfacing with the faceplate 102b. A ram coupler 76 of a ram 74 (Figure 2C), which are each part of a syringe plunger drive assembly 56 for the syringe 86b, is positioned in proximity to the faceplate 102b when mounted to the powerhead 50. Details regarding the syringe plunger drive assembly 56 again will be discussed in more detail below in relation to Figure 2C. Generally, the ram coupler 76 may be coupled with the syringe plunger 90b of the syringe 86b, and the ram coupler 76 and ram 74 (Figure 2C) may be moved relative to the powerhead 50 to move the syringe plunger 90b along the axis 100b (Figure 2A). It may be such that the ram coupler 76 is engaged with, but not actually coupled to, the syringe plunger 90b when moving the syringe plunger 90b to discharge fluid through the nozzle 89b of the syringe 86b. The faceplate 102b may be moved at least generally within a plane that is orthogonal to the axes 100a, 100b (associated with movement of the syringe plungers 90a, 90b, respectively, and illustrated in Figure 2A), both to mount the faceplate 102b on and remove the faceplate 102b from its mounting 82b on the powerhead 50. The faceplate 102b also may be used to couple the syringe plunger 90b with its corresponding ram coupler 76 on the powerhead 50. In this regard, the facepiate 102b may include a handle 106b. Generally and with the syringe 86b being initially positioned within the faceplate 102b, the syringe 86b may be rotated along its long axis 100b (Figure 2A) and relative to the faceplate 102b. This rotation may be realized by moving the handle 106b, by grasping and turning the syringe 86b, or both. In any case, this rotation moves/translates both the syringe 86b and the faceplate 102b at least generally within a plane that is orthogonal to the axes 100a, 100b (associated with movement of the syringe plungers 9Oa₁ 90b, respectively, and illustrated in Figure 2A). Rotating the syringe 86b in one direction moves/translates the syringe 86b and faceplate 102b in an at least generally downward direction to couple the syringe plunger 90b with its corresponding ram coupler 76. Rotating the syringe 86b in the opposite direction moves/translates the syringe 86b and faceplate 102b in an at least generally upward direction to uncouple its syringe plunger 90b from its corresponding ram coupler 76.

As illustrated in Figure 2B, the syringe plunger 90b includes a plunger body 92 and a syringe plunger coupler 94. This syringe plunger coupler 94 includes a shaft 98 that extends from the plunger body 92, along with a head 96 that is spaced from the plunger body 92. Each of the ram couplers 76 includes a larger slot that is positioned behind a smaller slot on the face of the ram coupler 76. The head 96 of the syringe plunger coupler 94 may be positioned within the larger slot of the ram coupler 76, and the shaft 98 of the syringe plunger coupler 94 may extend through the smaller slot on the face of the ram coupler 76 when the syringe plunger 90b and its corresponding ram coupler 76 are in a coupled state or condition. The syringe plunger 90a may include a similar syringe plunger coupler 94 for interfacing with its corresponding ram coupler 76.

The powerhead 50 is utilized to discharge fluid from the syringes 86a, 86b in the case of the power injector 40. That is, the powerhead 50 provides the motive force to discharge fluid from each of the syringes 86a, 86b. One embodiment of what may be characterized as a syringe plunger drive assembly or syringe plunger driver is illustrated in Figure 2C, is identified by reference numeral 56, and may be utilized by the powerhead 50 to discharge fluid from each of the syringes 86a, 86b. A separate syringe plunger drive assembly 56 may be incorporated into the powerhead 50 for each of the syringes 86a, 86b. In this regard and referring back to Figures 2A-B, the powerhead 50 may include hand-operated knobs 80a and 80b for use in separately controlling each of the syringe plunger drive assemblies 56.

Initially and in relation to the syringe plunger drive assembly 56 of Figure 2C, each of its individual components may be of any appropriate size, shape, configuration and/or type. The syringe plunger drive assembly 56 includes a motor 58, which has an output shaft 60. A drive gear 62 is mounted on and rotates with the output shaft 60 of the motor 58. The drive gear 62 is engaged or is at least engageable with a driven gear 64. This driven gear 64 is mounted on and rotates with a drive screw or shaft 66. The axis about which the drive screw 66 rotates is identified by reference numeral 68. One or more bearings 72 appropriately support the drive screw 66.

A carriage or ram 74 is movably mounted on the drive screw 66. Generally, rotation of the drive screw 66 in one direction axially advances the ram 74 along the drive screw 66 {and thereby along axis 68) in the direction of the corresponding syringe 86a/b, while rotation of the drive screw 66 in the opposite direction axially advances the ram 74 along the drive screw 66 (and thereby along axis 68) away from the corresponding syringe 86a/b. In this regard, the perimeter of at least part of the drive screw 66 includes helical threads 70 that interface with at least part of the ram 74. The ram 74 is also movably mounted within an appropriate bushing 78 that does not allow the ram 74 to rotate during a rotation of the drive screw 66. Therefore, the rotation of the drive screw 66 provides for an axial movement of the ram 74 in a direction determined by the rotational direction of the drive screw 66. The ram 74 includes a coupler 76 that that may be detachably coupled with a syringe plunger coupler 94 of the syringe plunger 90a/b of the corresponding syringe 86a/b. When the ram coupler 76 and syringe plunger coupler 94 are appropriately coupled, the syringe plunger 90a/b moves along with ram 74. Figure 2C illustrates a configuration where the syringe 86a/b may be moved along its corresponding axis WaJb without being coupled to the ram 74. When the syringe 86a/b is moved along its corresponding axis 100a/b such that the head 96 of its syringe plunger 90a/b is aligned with the ram coupler 76, but with the axes 68 still in the offset configuration of Figure 2C, the syringe 86a/b may be translated within a plane that is orthogonal to the axis 68 along which the ram 74 moves. This establishes a coupled engagement between the ram coupler 76 and the syringe plunger coupler 96 in the above-noted manner. The power injectors 10, 40 of Figures 1 and 2A-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 10, 40 include without limitation computed tomography or CT imaging, magnetic resonance imaging or MRI, SPECT imaging, PET imaging, X-ray imaging, angiographic imaging, optical imaging, and ultrasound imaging. The power injectors 10, 40 each could be used alone or in combination with one or more other components. The power injectors 10₁ 40 each may be operativeiy interconnected with one or more components, for instance so that information may be conveyed between the power injector 10, 40 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 10, 40, including without limitation single-head configurations (for a single syringe) and dual-head configurations (for two syringes). In the case of a multiple syringe configuration, each power injector 10, 40 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 10, 40 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 10, 40 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).

Figure 3A illustrates one embodiment of a drive train that is identified by reference numeral 110, that may be used to advance a syringe plunger 132 in at least one direction, and that may be incorporated by any appropriate power injector that utilizes at least one syringe. A number of characterizations may be made in relation to the syringe plunger 132, and which apply individually and in any combination: 1) the syringe plunger 132 may be of any appropriate size, shape, configuration, and/or type (e.g., syringe plunger 90a/90b in Figures 2A- C); 2) the syringe plunger 132 may be formed from any appropriate material or combination of materials; 3) the syringe plunger 132 may be incorporated by a syringe of any appropriate size, shape, configuration, and/or type (e.g., syringe 86a/86b in Figures 2A-C); and 4) the syringe plunger 132 may interact with the drive train 110 in any appropriate manner so that the syringe plunger 132 is advanced in at least one direction by the drive train 110 {e.g., in a direction to provide a fluid discharge from the associated syringe, for instance axiaily in accordance with arrow 134), although it should be appreciated that the drive train 110 could both extend the syringe plunger 132 (e.g., along a first axial path and in a first direction for fluid discharge) and retract the syringe plunger 132 (e.g., along the first axial path, but in a second direction that is opposite of the first direction). Regardless of whether the syringe plunger 132 is advanced in a single direction or bi-directionally by the drive train 110, the drive train 110 may provide a bi-directional output.

The drive train 110 includes a drive source 116a and a drive source 116b. Each of these drive sources 116a, 116b may be of any appropriate size, shape, configuration, and/or type (e.g., a brushed or brushless electric motor, a hydraulic motor, a pneumatic motor, a piezoelectric motor, or a stepper motor), including without limitation being the same or different in at least some respect. The drive source 116a has an associated selector 114a to establish an associated drive output 118a of any appropriate size, shape, configuration, and/or type. The drive source 116b has an associated selector 114b to establish an associated drive output 118b of any appropriate size, shape, configuration, and/or type. In one embodiment, each of the drive outputs 118a, 118b is in the form of a rotational output (e.g., a rotating shaft). The selector 114a may be used to change the direction of the output 118a from the drive source 116a, to change the magnitude of the output 118a from the drive source 116a, or both. Similarly, the selector 114b may be used to change the direction of the output 118b from the drive source 116b, to change the magnitude of the output 118b from the drive source 116b, or both. A rate at which the syringe plunger 132 is advanced is dependent upon both the drive output 118a from the drive source 116a and the drive output 118b from the drive source 116b. This is schematically represented by a syringe plunger drive interface 120 in Figure 3A, and that is disposed between each of the outputs 118a, 118b and the syringe plunger 132. That is, the syringe plunger drive interface 120 may be of any appropriate size, shape, configuration, and/or type (e.g., any structure or combination of structures) that allows the rate at which the syringe plunger 132 is advanced to be dependent upon both the drive output 118a from the drive source 116a and the drive output 118b from the drive source 116b. Each of the drive outputs 118a, 118b may interact with the syringe plunger drive interface 120 in any appropriate manner, including individually as shown or combinatively in some fashion.

Each of the drive sources 116a, 116b may be of either a variable speed type or a fixed speed type, their respective outputs 118a, 188b may be unidirectional or bidirectional (e.g., a clockwise rotational output, a counterclockwise rotational output), or both. Each of the selectors 114a, 114b may be of any appropriate size, shape, configuration, and/or type so as to control their respective drive source 116a, 116b, more specifically their respective drive outputs 118a, 188b. Figure 3B illustrates a representative selector 114 for a variable speed drive source, and that may be utilized as the selector 114a and/or 114b. The selector 114 of Figure 3B may be set at a desired speed between a maximum speed for a drive output in a first direction and which is designated as VMax(oi> (e.g., a clockwise rotational output) and a maximum speed for a drive output in a second direction and which is designated as V_Maχ(D2) (e.g., a counterclockwise rotational output). The "off position for the selector 114 may coincide with there not being any associated drive output, or where the magnitude of the drive output is zero. In the case of a fixed speed drive source, the seiector 114 could be configured to provide a single speed in a first direction and a single speed in a second direction, where these speeds are of the same or different absolute values. Another embodiment of a drive train is illustrated in Figure 4A and is identified by reference numeral 140.

Corresponding components between the drive train 110 of Figure 3A and the drive train 140 of Figure 4A are identified by the same reference numerals. The drive train 140 of Figure 4A may be used to advance a syringe plunger of any appropriate size, shape, configuration, and/or type in at least one direction for delivery of a fluid (e.g., along an axis coinciding with double-headed arrow 142), and may be incorporated by any appropriate power injector that utilizes at least one syringe.

The drive train 140 of Figure 4A includes a drive source 116a having an associated selector 114a to establish an associated drive output 118a, as well as a drive source 116b having an associated selector 114b to establish an associated drive output 118b. The drive output 118a drives/rotates a threaded drive screw 144 (e.g., at least generally about the axis coinciding with double-headed arrow 142), while the drive output 188b drives/rotates a ram 20 of the above-noted type (e.g., at least generally about the axis coinciding with double- headed arrow 142). In one embodiment, the ram 20 may be characterized as including a threaded nut 21 that engages the threaded exterior of the drive screw 144, and where the body of the ram 20 is appropriately attached to and extends from this nut 21. The nut 21 could also be characterized as being a separate piece from the ram 20, but where the ram is mounted to and moves along with the nut 21. Regardless, relative rotational motion between the ram 20 and the drive screw 144 axially advances the ram 20 along the drive screw 144 and in accordance with the double-headed arrow 142. Relative rotational motion in one direction axially advances the ram 20 along the drive screw 144 to the right in the view presented in Figure 4A, while relative rotational motion in the opposite direction axially advances the ram 20 along the drive screw 144 to the left in the view presented in Figure 4A. The ram 20 may interact with a syringe plunger in any appropriate manner, may advance the syringe plunger in only one direction, or may both extend and retract the syringe plunger.

Another embodiment of a drive train is illustrated in Figure 4B and is identified by reference numeral 150. Corresponding components between the drive train 110 of Figure 3A and the drive train 150 of Figure 4B are identified by the same reference numerals. The drive train 150 of Figure 4A may be used to advance a syringe plunger 132 of any appropriate size, shape, configuration, and/or type in at least one direction for delivery of a fluid (e.g., in accordance with arrow 134), and may be incorporated by any appropriate power injector that utilizes at least one syringe.

The drive train 150 of Figure 4B includes a gearbox 152. The gearbox 152 may be of any appropriate size, shape, configuration, and/or type. Each of the drive outputs 118a, 118b from their respective drive sources 116a, 116b drive/define inputs to the gearbox 152. A gearbox output 154 drives/axially advances the syringe plunger 132 in at least one direction for delivery of a fluid (e.g., in accordance with single-headed arrow 134). The gearbox 152 could also be used to provide bidirectional movement for the syringe plunger 132 (e.g., along an axial path in opposite directions). Another embodiment of a drive train is illustrated in Figure 4C and is identified by reference numeral 160. Corresponding components between the drive train 110 of Figure 3A and the drive train 160 of Figure 4C are identified by the same reference numerals. The drive train 160 of Figure 4C may be used to advance a syringe plunger 132 of any appropriate size, shape, configuration, and/or type in at least one direction for delivery of a fluid (e.g., in accordance with arrow 134), and may be incorporated by any appropriate power injector that utilizes at least one syringe.

The drive train 160 of Figure 4C includes a planetary gear system or PGS 162. Components of the PGS 162 include a PGS component 164, a PGS component 166, and a PGS component 168. Each of the PGS components 164, 166, 168 are a separate one of a sun gear, a ring gear, or planet gear carrier having a plurality of planet gears freely and rotatably mounted thereon. Each PGS component 164, 166, 168 interacts with at least one other PGS component 164, 166, 168. In one embodiment, one of the PGS components 164, 166, 168 interacts with the other two of the PGS components 164, 166, 168, while these other two interact with only one of the PGS components 164, 166, 168. In one embodiment, each of the PGS components 164, 166, 168 are rotatable about a common axis in each of first and second directions (e.g., clockwise, counterclockwise). The drive source 116a drives or controls the rotation of the PGS component 164 (e.g., a ring gear), such that the drive output 118a may be characterized as one input for the PGS 162. The drive source 116b drives or controls the rotation of the PGS component 166 (e.g., a sun gear), such that the drive output 118b may be characterized as another input for the PGS 162. The syringe plunger 132 is driven/axially advanced by an output 170 of the PGS system 162. The PGS component 168 (e.g., a planet gear carrier) provides the output 170 in the illustrated embodiment. The PGS component 168 (the output for the illustrated embodiment) may be any one of a sun gear, a ring gear, or a planet gear carrier.

Another embodiment a drive train is illustrated in Figure 4D and is identified by reference numeral 180. Corresponding components between the drive train 160 of Figure 4C and the drive train 180 of Figure 4D are identified by the same reference numerals. The drive train 180 of Figure 4D may be used to advance a syringe plunger of any appropriate size, shape, configuration, and/or type in at least one direction for delivery of a fluid, and may be incorporated by any appropriate power injector that utilizes at least one syringe.

The drive train 180 of Figure 4D shows an exemplary way of using a motion from the PGS 162 to axially advance a syringe plunger. In this regard, the output 170 from the PGS component 168 may be in the form of and/or used to control the rotation of/rotate a threaded drive screw 144 of the type discussed above in relation to the drive train 140 of Figure 4A. Relative rotational motion between the drive screw 144 and the ram 20 again causes the ram 20 to move along an axis coinciding with the length dimension of the drive screw 144. Axial motion of the ram 20 along the drive screw 144 may be realized in each direction, and in accordance with the double-headed arrow 142, by changing the direction of the relative rotational motion between the drive screw 144 and the ram 20. The ram 20 again interacts with a syringe plunger to advance the same in at least one direction. One embodiment of a planetary gear system is illustrated in Figure 5, is identified by reference numeral

190, and may be used by each of the drive trains 160, 180 of Figures 4C and 4D or by any other appropriate syringe plunger drive train. The planetary gear system 190 includes an outer ring gear 192, a sun gear 194, and a plurality of planet gears 198. The ring gear 192 and sun gear 194 each rotate about a common axis 200. The various planet gears 198 are freely and rotatably mounted on a planet gear carrier 196 that may also rotate about the axis 200. Any appropriate number of planet gears 198 may be utilized. Generally, the planet gears 198 revolve about the sun gear 194. Stated another way, the planet gear carrier 196 rotates about the axis 200, along with the ring gear 192 and sun gear 194 as noted above.

Each of the ring gear 192, sun gear 194, and the various planet gears 198 may be of any appropriate size and may utilize any appropriate number of gear teeth. Any appropriate number of planet gears 198 may be utilized. Each planet gear 198 engages each of the sun gear 194 and the ring gear 192. Therefore, the various planet gears 198 may be characterized as being disposed between the ring gear 192 and the sun gear 194. One way to implement the planetary gear system 190 of Figure 5 into the drive train 180 of Figure 4D is as follows. The output 118a of the drive source 116a may be used to drive the ring gear 192 - to rotate the ring gear 192 about the axis 200. The output 118b of the drive source 116b may be used to drive the sun gear 194 - to rotate the sun gear about the axis 200. The planet gear carrier 196 may be used to drive the drive screw 144. That is, rotation of the planet gear carrier 196 about the axis 200 may be used to rotate the drive screw 144. The drive screw 144 may be coaxially disposed with the axis 200 or otherwise. It should be appreciated that the sun gear 194 or the ring gear 192 could also be used to drive the drive screw 144.

If the ring gear 192 is rotated clockwise in the view shown in Figure 5 and the sun gear 194 is held stationary (e.g., via the drive source 116b being configured such that its output 118b is "zero"), the planet gear carrier 196 would rotate clockwise as well, but at a slower velocity than the ring gear 192 (e.g., the planet gears 198 would revolve clockwise about the axis 200/sun gear 194). The same is true if the sun gear 194 is rotated clockwise in the view shown in Figure 5 in the ring gear 192 is held stationary (e.g., via the drive source 116a being configured such that its output 118a is "zero"). If both the sun gear 194 and the ring gear 192 are rotated at the same time and in the same direction, the planet gear carrier 196 rotates counterclockwise at a much higher speed (e.g., the planet gears 198 would revolve counterclockwise about the axis 200/sun gear 194 at a higher speed). Conversely, if the ring gear 192 and the sun gear 194 are rotated in opposite directions about the axis 200 (one clockwise and one counterclockwise in the view shown at Figure 5) the planet gear carrier 196 rotates at a much slower speed (e.g., the planet gears 198 would revolve about the axis 200/sun gear 194 at a much slower speed). Therefore, the planet gear carrier 196 may be rotated at a variety of rates, to in turn advance a syringe plunger at a variety of rates as well. Another embodiment of a drive train is illustrated in Figure 6 and is identified by reference numeral 210, and which uses a variation of the planetary gear system 190 of Figure 5. Corresponding components of the planetary gear systems illustrated in Figures 5 and 6 are identified by the same reference numeral. Those corresponding components that differ in at least some respect are identified by a "single prime" designation {e.g., planetary gear system 190' in Figure 6). The drive train 210 of Figure 6 may be used to advance a syringe plunger of any appropriate size, shape, configuration, and/or type in at least one direction for delivery of a fluid (e.g., along axis 200), and may be incorporated by any appropriate power injector that utilizes at least one syringe. The drive train 210 of Figure 6 includes a drive source 212a having an associated selector (not shown) to provide an associated drive output that is transferred to the sun gear 194 in the illustrated embodiment (via a driven shaft 214), as well as a drive source 212b having an associated selector (not shown) to provide an associated drive output that is transferred to the ring gear 192 in the illustrated embodiment {via a driven pulley 216 and a drive belt 202, chain, or the like). Each of the drive sources 212a, 212b may be separately operated to rotate the sun gear 194 and ring gear 192, respectively in each of first and second directions {e.g., clockwise and counterclockwise rotations about axis 200).

A plurality of planet gears 198 again are interposed between the sun gear 194 and the ring gear 192. Instead of a plate-like structure, the planet gear carrier 196' in the embodiment of Figure 6 is in the form of separate shafts that extend from each individual planet gear 198 and that merge into a common output shaft 204. Each planet gear 198 remains freely rotatable relative its respective shaft of the planet gear carrier 196'. The planet gear carrier 196' may be an integrally-formed structure with the output shaft 204 as shown (e.g., no joints of any kind), the planet gear carrier 196' and the output shaft 204 may be defined by one or more separately-formed parts, or the planet gear carrier 196' may actually be defined by the structure shown in Figure 6, which could be appropriately coupled with a separate output shaft. Other configurations may be appropriate for the planet gear carrier 196' as well.

The output shaft 204 is driven by rotation of the planet carrier 196'. Rotation of the output shaft 204 may be used to advance an associated syringe plunger in at least one direction. Exterior threads {not shown) may be formed on the output shaft 204 {e.g., like that of a conventional drive screw), and a ram (e.g., ram 20) may be mounted on this output shaft 204 and may interact with a syringe plunger in any appropriate manner. Rotation of the output shaft 204 in one rotational direction may move this ram along the length of the output shaft 204 in one axial direction {to move the associated syringe plunger in one direction, for instance for a fluid discharge stroke), while rotation of the output shaft 204 in the opposite rotational direction may move this ram along the length of the output shaft 204 in the opposite axial direction {e.g., to retract the associated syringe plunger for a fluid-loading operation; to reposition the ram for a subsequent fluid discharge stroke).

Each of the drive trains discussed herein may be placed in a number of different basic drive train configurations to advance a syringe plunger, to in turn deliver a fluid. One basic drive train configuration is that the output from two drive sources 116a, 116b may be summed together to advance a syringe plunger 132, Another basic drive train configuration is that the differential of the outputs from two drive sources 116a, 116b may be utilized to advance a syringe plunger 132. Yet another basic drive train configuration is that the output from any one of the drive sources 116a, 116b may be utilized to individually advance a syringe plunger 132 (i.e., the magnitude of the other drive output 118a, 118b would be zero in this case).

There are a number of advantages associated with using a drive train having multiple drive sources to advance a syringe plunger. One is that a drive train having a pair of drive sources may be configured such that a syringe plunger dynamic range ratio in this case is larger than the individual dynamic range ratios of the two drive sources. The phrase "dynamic range ratio" herein means a ratio of a maximum output to a minimum output. The larger the dynamic range ratio, the larger the range of speeds over which a syringe plunger may be advanced. One embodiment has the dynamic range ratio of the syringe plunger (the ratio of the maximum output to the syringe plunger, to the minimum output to the syringe plunger, all through using a drive train with multiple drive sources) being at least 10O times greater than the largest of the dynamic range ratios of the individual drive sources (the ratio of their respective maximum output to minimum output). Another embodiment has the dynamic range ratio of the syringe plunger (the ratio of the maximum output to the syringe plunger, to the minimum output to the syringe plunger, all through using a drive train with multiple drive sources) being at least 200 times greater than the largest of the dynamic range ratios of the individual drive sources (the ratio of their respective maximum output to minimum output).

Syringe plunger drive trains that utilize multiple drive sources may allow the size of the drive sources 116a, 116b and other drive components to be reduced. This in turn may reduce the total amount of power required to advance the syringe plunger. Another benefit of the syringe plunger drive trains described herein is that control may be enhanced when a syringe plunger is being advanced at slower speeds. For instance, the drive sources 116a, 116b may be operated at higher speeds and yet still advance the syringe plunger at a relatively slower speed (e.g., by operating in opposite directions). Each drive source 116a, 116b may also be operated in a desirably efficient range when incorporated by a syringe plunger drive train of the types described herein.

Theoretical Example

The planetary gear system 190 of Figure 5 may be incorporated into the syringe plunger drive train 180 of Figure 4D with the output 118a of the drive source 116a driving the ring gear 192, with the output 118b of the drive source 116b driving the sun gear 194, and with the planet gear carrier 196 driving the drive screw 144. Consider the case where a maximum output 118a of the drive source 116a alone provides a fluid delivery rate of 20 milliliters per second, where a minimum output 118a of the drive source 116a alone provides a fluid delivery rate of 10 milliliters per second, where a maximum output 118b of the drive source 116b alone provides a fluid delivery rate of 20 milliliters per second, and where a minimum output 118b of the drive source 116b alone provides a fluid delivery rate of 10 milliliters per second. The drive source 116a alone may be characterized as having a dynamic range ratio of 2:1 in this instance, where the dynamic range ratio for the drive source 116a is a ratio of its maximum output 118a to its minimum output 118a. Similarly, the drive source 116b alone may be characterized as having a dynamic range ratio of 2:1 in this instance, where the dynamic range ratio for the drive source 116b is a ratio of its maximum output 118b to its minimum output 118b. However, the syringe plunger dynamic range ratio provided through the drive train 180 and its inclusion of the planetary gear system 190 in the above-noted manner is actually 400:1 , where the syringe plunger dynamic range ratio is a ratio of a maximum output to the syringe piunger via the planetary gear system 190, to a minimum output to the syringe plunger via the planetary gear system 190.

The following table provides a representative listing of speeds that may be realized for this Example and which illustrates the above-noted dynamic range ratios for each of the drive source 116a (2:1 ), the drive source 116b (2:1), and the syringe plunger via the planetary gear system 190 (400:1). It should be noted that the speeds noted in the following table are expressed in terms of a delivery rate (e.g., an injection rate). In the case of the inputs to the planetary gear system 190, namely the ring gear 192 and the sun gear 194, the discharge rate values are those that would be achieved solely by the outputs of the ring gear 192 and the sun gear 194.

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 application(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:

1. A power injector, comprising: a syringe piunger; a first drive source that provides a first output; and a second drive source that provides a second output, wherein a rate at which said syringe plunger is advanced is dependent upon each of said first and second outputs.

2. The power injector of Claim 1 , further comprising: a drive screw that is threaded; a ram threadably mounted on and movable along said drive screw, wherein said first drive source controls a rotation of said drive screw, and wherein said second drive source controls a rotation of said ram.

3. The power injector of Claim 2, wherein said ram comprises a threaded nut mounted on said drive screw that is rotatable by said second drive source.

4. The power injector of any one of Claims 2-3, wherein each of said drive screw and said ram are rotatable in each of first and second directions that are opposite of each other.

5. The power injector of any one of Claims 2-4, wherein a relative rotational movement between said drive screw and said ram axially advances said ram along said drive screw.

6. The power injector of any one of Claims 2-5, wherein said drive screw and said ram are rotatable about a common axis.

7. The power injector of Claim 1 , further comprising: a gearbox, wherein each of said first drive source, said second drive source, and said syringe plunger are operatively interconnected with said gearbox.

8. The power injector of Claim 1 , further comprising: a gearbox comprising first and second gearbox inputs and a gearbox output, wherein said first and second drive sources drive said first and second gearbox inputs, respectively, and wherein said syringe plunger is driven by said gearbox output.

9. The power injector of Claim 1 , further comprising: a planetary gear system, wherein each of said first drive source, said second drive source, and said syringe plunger are operatively interconnected with said planetary gear system.

10. A power injector, comprising: a syringe plunger; a first drive source; a second drive source; and a planetary gear system that in turn comprises a first planetary gear system component, a second planetary gear system component, and a third planetary gear system component, wherein said first and second planetary gear system components are each inputs for said planetary gear system, wherein said third planetary gear system component is an output for said planetary gear system, wherein said first and second drive sources drive said first and second planetary gear system components, respectively, and wherein said syringe plunger is driven by said third planetary gear system component.

11. The power injector of Claim 10, wherein said first drive source provides a first output, and wherein said second drive source provides a second output.

12. The power injector of any one of Claims 1-11, wherein a sum of outputs from said first and second drive sources advances said syringe plunger in a first direction when said fluid discharge device is in a first configuration.

13. The power injector of any one of Claims 1-12, wherein a differential of outputs from said first and second drive sources advances said syringe plunger in a first direction when said fluid discharge device is in a second configuration.

14. The power injector of any one of Claims 1-13, wherein an output from only one of said first and second drive sources advances said syringe plunger in a first direction when said fluid discharge device is in a third configuration.

15. The power injector of any one of Claims 1-9 and 11-14, wherein each of said first and second outputs are rotational outputs, and wherein each of said first and second drive sources are configured to provide said rotational outputs in each of first and second directions that are opposite of each other.

16. The power injector of any one of Claims 1-9 and 11-15, wherein each of said first and second outputs are rotational outputs, wherein said first drive source is configurable to provide a first rotational output in a first direction, and wherein said second drive source is configurable to provide a second rotational output in said first direction.

17. The power injector of any one of Claims 1-9 and 11-16, wherein each of said first and second outputs are rotational outputs, wherein said first drive source is configurable to provide a first rotational output in a first direction, and wherein said second drive source is configurable to provide a second rotational output in a second direction that is opposite of said first direction.

18. The power injector of any one of Claims 1-9 and 11-17, wherein each of said first and second outputs are rotational outputs, wherein said first drive source is configurable to provide a first rotational output in a first direction, and wherein said second drive source is configurable to not provide any said rotational output.

19. The power injector of any one of Claims 1 -9 and 11 -18, wherein each of said first and second outputs are rotational outputs, wherein said first drive source is configurable to provide a first rotational output in a second direction, and wherein said second drive source is configurable to provide a second rotational output in said second direction.

20. The power injector of any one of Claims 1-9 and 11-19, wherein each of said first and second outputs are rotational outputs, wherein said first drive source is configurable to provide a first rotational output in a second direction, and wherein said second drive source is configurable to provide a second rotational output in a first direction that is opposite of said second direction.

21. The power injector of any one of Ciaims 1-9 and 11-20, wherein each of said first and second outputs are rotational outputs, wherein said first drive source is configurable to provide a first rotational output in a second direction, and wherein said second drive source is configurable to not provide any said rotational output.

22. The power injector of any one of Claims 1-9 and 11-21 , wherein each of said first and second outputs are rotational outputs, wherein said first drive source is configurable to not provide any said rotational output, and wherein said second drive source is configurable to provide a second rotational output in a first direction.

23. The power injector of any one of Claims 1 -9 and 11 -22, wherein each of said first and second outputs are rotational outputs, wherein said first drive source is configurable to not provide any said rotational output, and wherein said second drive source is configurable to provide a second rotational output in a second direction.

24. The power injector of any one of Claims 1-23, wherein a first dynamic range ratio is a ratio of a maximum output of said first drive source to a minimum output of said first drive source, wherein a second dynamic range ratio is a ratio of a maximum output of said second drive source to a minimum output of said second drive source, and wherein a syringe plunger dynamic range ratio is a ratio of a maximum output to said syringe plunger to a minimum output to said syringe plunger, and wherein said syringe plunger dynamic range ratio is greater than each of said first and second dynamic range ratios.

25. The power injector of any one of Claims 1-24, wherein a first dynamic range ratio is a ratio of a maximum output of said first drive source to a minimum output of said first drive source, wherein a syringe plunger dynamic range ratio is a ratio of a maximum output to said syringe plunger to a minimum output to said syringe plunger, and wherein said syringe plunger dynamic range ratio is at least 100 times greater than said first dynamic range ratio.

26. The power injector of any one of Claims 1-24, wherein a first dynamic range ratio is a ratio of a maximum output of said first drive source to a minimum output of said first drive source, wherein a syringe plunger dynamic range ratio is a ratio of a maximum output to said syringe plunger to a minimum output to said syringe plunger, and wherein said syringe plunger dynamic range ratio is at least 200 times greater than said first dynamic range ratio.

27. The power injector of any one of Claims 1 and 11-26, further comprising: a planetary gear system that in turn comprises a first planetary gear system component, a second planetary gear system component, and a third planetary gear system component, wherein said first and second planetary gear system components are each inputs for said planetary gear system, wherein said third planetary gear system component is an output for said planetary gear system, wherein said first and second drive sources drive said first and second planetary gear system components, respectively, and wherein said syringe plunger is driven by said third planetary gear system component.

28. The power injector of any one of Claims 10 and 27, wherein each of said first, second, and third planetary gear system components are selected from the group consisting of a sun gear, planet gear carrier, and a ring gear, wherein a plurality of planet gears are rotatably mounted on said planet gear carrier.

29. The power injector of any one of Claims 10 and 27, wherein said first planetary gear system component is one of a sun gear, a planet gear carrier, and a ring gear, wherein said second planetary gear system component is another of said sun gear, said planet gear carrier, and said ring gear, wherein said third planetary gear system component is another of said sun gear, said planet gear carrier, and said ring gear, and wherein a plurality of planet gears are rotatably mounted on said planet gear carrier.

30. The power injector of any one of Claims 10 and 27-29, wherein said first, second, and third planetary gear system components are rotatable about a common axis.

31. The power injector of any one of Claims 1 and 11-30, further comprising: a sun gear; a planet gear carrier; a plurality of planet gears rotatably mounted on said planet gear carrier; and a ring gear, wherein said plurality of planet gears engage each of said sun gear and said ring gear, wherein said first drive source drives said ring gear, wherein said second drive source drives said sun gear, and wherein said planet gear carrier drives said syringe plunger.

32. The power injector of any one of Claims 1-31 , wherein said syringe plunger is movable along an axial path in at least a first direction by an operation of at least one of said first and second drive sources.

33. The power injector of any one of Claims 1 -32, wherein each of said first and second drive sources are operable in each of first and second directions that are opposite of each other.

34. The power injector of any one of Claims 1-33, further comprising: a drive screw that is threaded; and a ram threadably and movably mounted on said drive screw, wherein a relative rotation between said drive screw and said ram causes said ram to move along an axis coinciding with a length dimension of said drive screw, and wherein said relative rotation is dependent upon each of said first and second outputs.

35. The power injector of any one of Claims 1-34, wherein each of said first and second drive sources are selected from the group consisting of a brushed or brushless electric motor, a hydraulic motor, a pneumatic motor, a piezoelectric motor, or a stepper motor.

36. The power injector of any one of Claims 1 -35, further comprising: a syringe barrel, wherein said syringe plunger is disposed within said syringe barrel.

37. A power injector comprising a powerhead and the power injector of any one of Claims 1-36.

38. A method of operation for a power injector, comprising the steps of: operating first and second drive sources on a simultaneous basis; advancing a syringe plunger using said operating step; and delivering a fluid using said advancing step.

39. The method of Claim 38, further comprising the steps of: driving a first component with said first drive source; and driving a second component with said second drive source, wherein a motion of each of said first and second components contributes to said advancing step.

40. The method of Claim 39, wherein said first and second components are each part of a planet gear set.

41. The method of Claim 39, wherein said first component is a drive screw that is threaded, and wherein said second component is a ram that is threadably mounted on said drive screw.

42. The method of any one of Claims 38-41 , wherein said operating step comprises summing outputs from said first and second drive sources for said advancing step.

43. The method of any one of Claims 38-41, wherein said operating step comprises using a differential of outputs from said first and second drive sources for said advancing step.

44. The method of any one of Claims 38-43, further comprising the step of: injecting said fluid into a patient from said delivering step.