WO2013066730A2

WO2013066730A2 - Power injector with soft start injection

Info

Publication number: WO2013066730A2
Application number: PCT/US2012/062017
Authority: WO
Inventors: Brandon Craft; Natalie Scott
Original assignee: Mallinckrodt Llc
Priority date: 2011-11-03
Filing date: 2012-10-26
Publication date: 2013-05-10
Also published as: WO2013066730A3

Abstract

Power injector control logic (110) that includes ramp-up logic (120) is disclosed. The ramp-up logic (120) controls an input signal to a motorized drive source of a power injector to advance the drive ram from a stationary state to an initial velocity that is associated with an initial flow rate(114) of an injection protocol (112) to be executed by the power injector.

Description

POWER INJECTOR WITH SOFT START INJECTION

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a non-provisional patent application of, and claims priority to, pending U.S.

Provisional Patent Application Serial No. 61/555,157, that is entitled "POWER INJECTOR WITH SOFT START INJECTION," that was filed on 3 November, 2011, and the entire disclosure of which is hereby incorporated by reference in its entirety herein.

FIELD OF THE INVENTION

The present invention generally relates to fluid delivery devices and, more particularly, to controlling the rate at which the velocity of a syringe plunger is increased to start an injection protocol.

BACKGROUND

Various medical procedures require that one or more medical fluids be injected into a patient. For example, medical imaging procedures oftentimes involve the injection of contrast media into a patient, possibly along with saline and/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 axially 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. 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.

SUMMARY

The present invention is embodied by a power injector or fluid delivery device that includes a motorized drive source, a drive ram, and power injector control logic. The drive ram is operatively interconnected with the motorized drive source and is movable along an axial path. The power injector control logic utilizes both an injection protocol and a ramp-up profile. The ramp-up profile controls an input signal to the motorized drive source to advance the drive ram from a stationary state or at-rest position, to an initial velocity that is associated with an initial flow rate used by the injection protocol (i.e., the first-in-time flow rate used by the injection protocol). In a first aspect of the present invention, the ramp-up profile used by the above-noted power injector utilizes at least one non-linear velocity increase of the drive ram. In a second aspect of the present invention, one part of the ramp-up profile used by the above-noted power injector accelerates the drive ram at one acceleration rate, and another part of this ramp-up profile accelerates the drive ram at a different acceleration rate. In a third aspect of the present invention, the ramp-up profile used by the above-noted power injector is operable only when the initial flow rate satisfies a predetermined flow rate standard.

A number of feature refinements and additional features are separately applicable to each of the first, second, and third aspects of the present invention. These feature refinements and additional features may be used individually or in any combination. As such, each of the following features that will be discussed may be, but are not required to be, used with any other feature or combination of features of the first, second, and third aspects. The following discussion, up to the start of the discussion on a fourth aspect of the present invention, pertains to each of the first, second, and third aspects.

The ramp-up profile may be configured to continually increase the velocity of the drive ram progressing from its stationary state to the initial velocity (associated with providing the initial flow rate for the injection protocol). The ramp-up profile may be configured such that the velocity of the drive ram is never reduced progressing from its stationary state to the initial velocity. At least part of ramp-up profile may be configured to accelerate the drive ram at something other than a constant rate (e.g., such that the velocity of the drive ram does not linearly increase from its stationary state to the initial velocity). A continually changing acceleration of the drive ram may be provided by the ramp-up profile. In one embodiment, the ramp-up profile accounts for a spring constant of at least one of (and thereby encompassing accounting for each of) a syringe that is installed on the power injector and any tubing that is connected with the syringe for delivering fluid to a patient.

Each of the first, second, and third aspects may be used in combination with one or more of the other first, second, or third aspects. The ramp-up profile may provide for a non-linear velocity increase of the drive ram progressing from its stationary state to the initial velocity (associated with providing the initial flow rate for the injection protocol). One part of the ramp-up profile may accelerate the drive ram at one acceleration rate, and another part of this ramp-up profile may accelerate the drive ram at a different acceleration rate. In one embodiment, the ramp-up profile uses a first acceleration rate, followed at some point in time by a second acceleration rate that is of a smaller magnitude than the first acceleration rate. The ramp-up profile used by the above-noted power injector may be automatically activated, for instance when the initial flow rate satisfies a predetermined threshold flow rate. One option is for the ramp-up profile to automatically change from a deactivated state to an activated state upon the satisfaction of this predetermined threshold flow rate (i.e., without user input). In the case of the third aspect, any appropriate ramp-up profile may be utilized, including where the ramp-up profile is configured to provide for a linear velocity increase (e.g., a constant acceleration; a single acceleration rate). The ramp-up profile may be disposable in each of active and deactivated states. The default state for the ramp-up profile could be either the active state or the deactivated state. A changing of the state of the ramp-up profile could be in response to user input (e.g., through any appropriate input device(s) for the power injector). The ramp-up profile could be integrated to automatically change between deactivated and activated states based upon the satisfaction of a predetermined condition (i.e., without user input). In one embodiment, when the initial flow rate for an injection protocol satisfies a predetermined threshold flow rate (e.g., when the initial flow rate is greater than the predetermined threshold flow rate; when the initial flow rate is at least as great as the predetermined threshold flow rate), the power injector control logic may be configured to automatically dispose the ramp-up profile in an activated state or to enable the ramp-up profile. In one embodiment, when the initial flow rate for an injection protocol fails to satisfy a predetermined threshold flow rate, the power injector control logic is configured to automatically dispose the ramp-up profile in a deactivated state or to disable the ramp-up profile (e.g., when the initial flow rate is smaller than the predetermined threshold flow rate; when the initial flow rate is no greater than the predetermined threshold flow rate).

A fourth aspect of the present invention is embodied by a power injector or fluid delivery device that includes a motorized drive source, a drive ram, power injector control logic, and a first user input device. The drive ram is operattvely interconnected with the motorized drive source and is movable along an axial path. The power injector control logic utilizes an injection protocol and at least two ramp-up profiles (e.g., a first ramp-up profile and a second ramp-up profile). Each such ramp-up profile controls an input signal to the motorized drive source to advance the drive ram from a stationary state or at-rest position, to an initial velocity that is associated with an initial flow rate used by the injection protocol (i.e., the first-in-time flow rate used by the injection protocol). The first and second ramp-up profiles differ in at least one respect from each other, and each of these ramp-up profiles may be selected through the first user input device.

A number of feature refinements and additional features are applicable to the fourth aspect of the present invention. These feature refinements and additional features may be used individually or in any combination. As such, each of the following features that will be discussed may be, but are not required to be, used with any other feature or combination of features of fourth aspect. The following discussion pertains to at least the fourth aspect of the present invention. The first user input device may be of any appropriate type, for instance a touchscreen, a keyboard, a mouse, or the like. Each of the first and second ramp-up profiles may be in accordance with the ramp- up profile addressed in relation to the first, second, and third aspects of the present invention.

An injection protocol for purposes of the present invention may include one or more phases that may be programmed in any appropriate manner (e.g., for automated operation of the power injector). Each phase of an injection protocol may include injection parameters such as a total amount of fluid to be injected and an injection flow rate, as well as possibly one or more injection delays (sometimes referred to as "holds" and/or "pauses") and each of which can be of finite or infinite duration. A phase of an injection protocol may be directed to injecting a single fluid at a single injection site. A phase of an injection protocol may be directed to simultaneously injecting multiple fluids (e.g., contrast media and saline) at a single injection site. A ramp-up profile in accordance with the present invention is utilized in relation to the flow rate associated with at least the first phase of an injection protocol, but could be used in relation to one or more other phases of the injection protocol as well.

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). 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 feast generally cylindrical encompasses the syringe barrel being cylindrical). Finally, a reference of a feature in conjunction with the phrase "in one embodiment" does not limit the use of the feature to a single embodiment.

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 any appropriate type and interconnected in any appropriate manner, or any combination thereof. This logic 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).

Any 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 one 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 and/or drawing of fluid and/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 an 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/ortype. 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 plunger driver, one or more drive sources may be associated with multiple syringe plunger drivers (e.g., incorporating a transmission of sorts to change the output from one syringe plunger to another syringe plunger), or a combination thereof. Re resentative drive source forms include a brushed or brushless electric motor, a hydraulic motor, a pneumatic motor, a piezoelectric motor, or a stepper motor.

Any such 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 imaging application (e.g., computed 5 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) and/or any appropriate medical diagnostic and/or therapeutic application (e.g., injection of chemotherapy, pain management, etc.). Any such 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, l o 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 any such power injector in any appropriate manner (e.g., detachabSy; front-loaded; rear-loaded; side-loaded), any appropriate medical fluid may be discharged from a given syringe of any such power injector (e.g., contrast media, therapeutic fluid, a radiopharmaceutical, saline, and

15 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 injection). Multiple syringes may 0 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), 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 5 least one direction, and possibly in two different, opposite directions.

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.0 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 3 is a schematic of one embodiment of power injector control logic that may utilize ramp-up logic in preparation for execution of an injection protocol.

Figure 4 is one embodiment of a ramp-up protocol that may be used by the power injector control logic of

Figure 3.

Figure 5 is one embodiment of a ramp-up implementation protocol that may be used by the power injector control logic of Figure 3.

Figure 6 is another embodiment of a ramp-up implementation protocol that may be used by the power injector control logic of Figure 3. 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 GUM 1 : 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 any 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 GU1 11 on a separate console that communicates with the powerhead 12, and also utilizes another GU1 11 that is on the powerhead 12. Each GU1 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 the 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 be fluidly 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 will 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-filled syringe 28 has been installed). Even when a ram coupler 22 and syringe plunger coupler 34 are utilized, 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 directly 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 doubie-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. Two syringes 86a, 86b for the power injector 40 are 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 or 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 AO; 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 100a,

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 06a 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 faceplate 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 90a, 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 discbarge 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 100a/b 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) and/or any appropriate medical diagnostic and/or therapeutic application (e.g., injection of chemotherapy, pain management, etc.). Representative medical imaging applications for the power injectors 10, 40 include without limitation computed tomography or CT imaging, magnetic resonance imaging or RI, 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 10, 40 each could be used alone or in combination with one or more other components. The power injectors 10, 40 each may be operatively 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, 0 may include any appropriate fluid (e.g., a medical fluid), for instance contrast media, therapeutic fluid, a radiopharmaceutical, saline, and any combination thereof. Each such syringe utilized by each of the power injectors 10, 0 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 power injector control logic is illustrated in Figure 3, is identified by reference numeral 110, and may be used by any appropriate power injector (e.g., power injector 10; power injector 40). Generally, the power injector control logic 110 provides for control of the manner in which a fluid is initially injected into a patient in preparation for execution of a particular injection protocol 112. An injection protocol 112 provides for programmed operation of a power injector. An injection protocol 112 may be in the form of a computerized program or the like, and may include one or more phases. Each phase of a given injection protocol 112 may include injection parameters such as a total amount of fluid to be injected and an injection flow rate, as well as possibly one or more injection delays (sometimes referred to as "holds" and/or "pauses"), where each injection delay can be of finite or infinite duration. A phase of an injection protocol 112 may be directed to injecting a single fluid at a single injection site. A phase of an injection protocol 112 may be directed to simultaneously injecting multiple fluids (e.g., contrast media and saline) at a single injection site.

The power injector control logic 110 may include one or more injection protocols 112 that may be stored on an appropriate computer-readable storage medium. A user may select an injection protocol 112 for execution in any appropriate manner (e.g., using any appropriate user input device(s) associated with the power injector, for instance using the remote console 42, the touch screen display 44, and/or graphical user interface 52). A user may input an injection protocol 112 to a power injector (e.g., using any appropriate user input device(s), for instance using the remote console 42, the touch screen display 44, and/or graphical user interface 52), and this injection protocol 112 may be executed without storing the same for any subsequent re-use. Storing an injection protocol 112 for subsequent use by the power injector control logic 110 alleviates the need to re-enter information that defines the injection protocol 112 at a later point-in-time.

The power injector control logic 110 illustrates having two stored injection protocols 112. Any number of injection protocols 112 could be stored and made available to the power injector control logic 110. Each injection protocol 112 will utilize at least one flow rate. Certain aspects of the power injector control logic 110 are used in relation to at least the initial or first-in-time flow rate 114 of the injection protocol 112 to be executed. If the injection protocol 12 includes only first, second, and third phases (executed in this order), the initial flow rate 114 would be the flow rate associated with the first phase, if the injection protocol 112 uses a single phase, the initial flow rate 114 for the injection protocol 112 would be the flow rate associated with this single phase.

The power injector control logic 110 includes ramp-up logic 120, and may include ramp-up profile implementation logic 118 (i.e., the ramp-up profile control logic 118 may be optional). Generally, the ramp-up profile implementation logic 118 may be used to control the availability of the ramp-up-logic 120 for use by the power injector control logic 110. The ramp-up logic 120 in turn may be used to control an input signal to a motorized drive source of the power injector (e.g., drive source 16 of the power injector 10; motor 58 of the power injector 40) to advance the drive ram of the power injector {e.g., ram 20 of power injector 10; ram 74 of power injector 40) from a stationary state to an initial velocity that is associated with the initial flow rate 14 for the injection protocol 112 to be executed. Various options for controlling this segment of movement of the drive ram may be utilized by the ramp-up logic 120. For instance, the ramp-up logic 120 may utilize one or more of: a non-linear velocity ramp-up profile 122a; a multiple acceleration rate ramp-up profile 122b; a non-constant acceleration ramp-up profile 122c; and a continually changing acceleration ramp-up profile 122d, Each of these ramp-up profiles 122a-d may be utilized to increase the speed of the ram of the power injector, from a stationary state to an initial velocity that is associated with the initial flow rate 114 for the injection protocol 112 to be executed, in a desirable manner. For instance, each of these ramp- up profiles may be configured to reduce the potential for damaging a patient's vessel when initiating an injection protocol 112 and/or to reduce the potential of the catheter becoming displaced from a patient's vessel when an injection protocol 112 is initiated. Moreover, each of these ramp-up profiles may be configured to account for a spring constant of one or more fluid transfer components (e.g., one or more syringes, tubing, or both) that may be used by the power injector to inject fluids into a patient pursuant to execution of an injection protocol 112.

One embodiment of a ramp-up protocol that may be used by the ramp-up logic 120 is illustrated in Figure 4 and is identified by reference numeral 160. A particular ramp-up profile 122 may be implemented by the protocol 160 in any appropriate manner (step 162; e.g., ramp-up profiles 122a-d). For instance, the power injector control logic 110 could be "hardwired" with a single ramp-up profile 122 for purposes of step 162 of the ramp-up protocol 160. Step 162 could entail a user selecting from multiple ramp-up profiles 122 that are stored and/or made availabfe to the power injector control logic 110 (e.g., Figure 5). Another option would be for step 162 of the ramp-up protocol 160 to allow a user to manually input a desired ramp-up profile 122 to the power injector (e.g., using any appropriate user input device(s)).

An input signal will be sent to the motorized drive source of the power injector (e.g., drive source 16 of power injector 10; motor 58 of power injector 40) pursuant to step 164 of the protocol 160 and in accordance with the ramp-up profile 122 that has been implemented. This input signal controls the motorized drive source of the power injector to advance the drive ram of the power injector (e.g., ram 20 of power injector 10; ram 74 of power injector 40) from a stationary state to an initial velocity that is associated with the initial flow rate 114 for the injection protocol 112 that is to be executed (step 166). Although the ramp-up protocol 160 is used in preparation for execution of an injection protocol 112, it could also be used in preparation for execution of any subsequent phase(s) of the injection protocol 112 (i.e., any phase after the first phase of the injection protocol 112).

The implemented ramp-up profile 122 from the ramp-up protocol 160 (step 162) may provide for a nonlinear increase in the velocity of the drive ram throughout the procession from its stationary state until reaching an initial velocity that is associated with the initial flow rate 114 for the injection protocol 112 that is to be executed (e.g., ramp-up profile 122a). The implemented ramp-up profile 122 from the ramp-up protocol 160 (step 162) may utilize two or more different acceleration rates to advance the drive ram from its stationary state to an initial velocity that is associated with the initial flow rate 114 for the injection protocol 112 that is to be executed (e.g., ramp-up profile 122b). The implemented ramp-up profile 122 from the ramp-up protocol 160 (step 162) may accelerate the drive ram at something other than a constant rate to advance the drive ram from its stationary state to an initial velocity that is associated with the initial flow rate 114 for the injection protocol 112 that is to be executed (e.g., ramp-up profile 122c). The implemented ramp-up profile 122 from the ramp-up protocol 160 (step 162) may continually change the rate at which the drive ram is accelerated in proceeding from its stationary state to an initial velocity that is associated with the initial flow rate 114 for the injection protocol 112 that is to be executed (e.g., ramp-up profile 122d).

One embodiment of a ramp-up profile implementation protocol is illustrated in Figure 5 and is identified by reference numeral 130. The ramp-up profile implementation protocol 130 may be utilized by step 162 of the ramp-up protocol 160 of Figure 4, may be implemented through the ramp-up profile implementation logic 118, or in any other appropriate manner by the power injector control logic 110. The various ramp-up profiles 122 (e.g., ramp-up profiles 122a-d) that are available to the power injector control logic 110 are conveyed and/or are made accessible to a user pursuant to step 132 of the implementation protocol 130 (e.g., presented on a display associated with the power injector). Multiple ramp-up profiles 122 that are stored and available to the power injector control logic 110 may be viewed, accessed, and/or retrieved by a user in any appropriate manner (e.g., using any appropriate input device(s) associated with the power injector; a drop-down menu). A particular ramp-up profile 122 may be selected by a user in any appropriate manner for purposes of step 134 (e.g., using any appropriate input device(s) associated with the power injector). Control could be returned to the ramp-up protocol 160 at this time, or the implementation protocol 130 could be configured to control the input signal to the motorized drive source of the power injector using the selected ramp-up profile (step 134) pursuant to execution of step 136 (to in turn advance the drive ram in the manner set forth in step 166 of the ramp-up protocol 160).

The power injector control logic 110 (Figure 3) could be configured to utilize the ramp-up logic 120 for each injection protocol 112 that is executed by a given power injector. Other configurations could be utilized. Figure 6 presents one embodiment of a ramp-up profile implementation protocol 140 that may be used by the ramp-up profile implementation logic 118 (Figure 3) to address the case where a ramp-up profile 122 is not necessarily used for each execution of an injection protocol 112. Certain information is required regarding the injection protocol 112 that is to be executed. Step 142 of the ramp-up profile implementation protocol 140 is directed to selecting or inputting the injection protocol 112 is to be executed. There is an associated initial flow rate 114 with this particular injection protocol 112.

The ramp-up profile implementation protocol 140 may acquire information on the initial flow rate 114 for the injection protocol 112 in any appropriate manner (e.g., step 142 need not be part of the protocol 140, so long as the implementation protocol 140 acquires information on the initial flow rate 114). The initial flow rate 114 of the injection protocol 112 is compared to a predetermined threshold flow rate 1 6 pursuant to step 144 of the implementation protocol 140. In the event the initial flow rate 114 satisfies the predetermined threshold flow rate 116 (e.g., "satisfaction" may be when the initial flow rate 114 is greater than the threshold flow rate 116; "satisfaction" may be when the initial flow rate 114 is equal to or greater than the threshold flow rate 116), the protocol 140 proceeds from step 146 to step 148.

The ramp-up logic 120 is automatically enabled or activated pursuant to step 148 of the ramp-up profile implementation protocol 140. A number of options may be available. A particular ramp-up profile 122 could be executed in response to the protocol 140 reaching step 148. Another option would be to require a user to enter/select a ramp-up profile 122 upon the protocol 140 reaching step 148 (or else, the injection protocol 112 would not run). For instance, the ramp-up profile implementation protocol 130 of Figure 5 could be executed pursuant to the implementation protocol 140 reaching step 148.

The "default" state for the ramp-up logic 120 could be "deactivated" or "disabled." Therefore and in this case, unless the initial flow rate 114 is determined to satisfy the predetermined threshold flow rate 116 pursuant to step 146 of the implementation protocol 140, the power injector control logic 110 (Figure 3) could be configured such that the ramp-up logic 20 would be remain in a deactivated/disabled state/condition. Another option would be for the "default" state of the ramp-up logic 120 to be "activated" or "enabled." In this case and where the initial flow rate 114 was determined to not satisfy the predetermined threshold flow rate 1 6 pursuant to step 146 of the implementation protocol 140, the ramp-up profile implementation protocol 140 could be configured: 1) such that the ramp-up logic 120 would be automatically changed to a deactivated/disabled state/condition for the relevant injection protocol 112; or 2) the user could be provided with the option to enter/select a ramp-up profile 122 (including via execution of the ramp-up profile implementation protocol 130).

The ramp-up profile implementation protocol 140 could be configured to have the ramp-up protocol 160 be operable only for injection protocols 112 that use an initial flow rate 114 that is of a higher magnitude. The implementation protocol 140 could also be configured to require use of the ramp-up protocol 160 if the initial flow rate 114 of an injection protocol satisfies the predetermined threshold flow rate 116 (e.g., for high initial flow rate conditions), but it may also allow for use of ramp-up protocol 160 for injection protocols 112 having an initial flow rate 114 that does not satisfy the predetermined threshold flow rate 116 (e.g., for lower initial flow rate conditions).

The power injector control logic 110 (including any ramp-up profile implementation logic 118 and the ramp- up logic 120) 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. The power injector control logic 110 (including any ramp-up profile implementation logic 118 and the ramp-up logic 120) 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). 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 motorized drive source;

an axially movable drive ram operatively interconnected with said motorized drive source; and

power injector control logic comprising an injection protocol and a ramp-up profile, wherein said injection protocol comprises an initial flow rate, wherein said ramp-up profile controls an input signal to said motorized drive source to advance said drive ram from a stationary state to an initial velocity that is associated with said initial flow rate, and wherein at least part of said ramp-up profile provides for a non-linear velocity increase of said drive ram.

2. A power injector comprising:

a motorized drive source;

power injector control logic comprising an injection protocol and a ramp-up profile, wherein said injection protocol comprises an initial flow rate, wherein said ramp-up-up profile controls an input signal to said motorized drive source to advance said drive ram from a stationary state to an initial velocity that is associated with said initial flow rate, wherein a first part of said ramp-up profile accelerates said drive ram at a first acceleration rate, and wherein a second part of said ramp-up profile accelerates said drive ram at a second acceleration rate that is different from said first acceleration rate.

3. A power injector comprising:

a motorized drive source;

power injector control logic comprising an injection protocol and a ramp-up profile, wherein said injection protocol comprises an initial flow rate, wherein said ramp-up profile allows said ramp-up profile to control an input signal to said motorized drive source to advance said drive ram from a stationary state to a velocity that provides said initial flow rate, and wherein operation of said ramp-up profile is required when said initial flow rate satisfies a predetermined threshold flow rate.

4. The power injector of any of claims 1-3, wherein said ramp-up profile continuously increases a velocity of said drive ram from said stationary state to said initial velocity.

5. The power injector of any of claims 1-4, wherein at least part of said ramp-up profile provides for other than acceleration of said drive ram at a constant rate.

6. The power injector of any of claims 1-5, wherein said ramp-up profile provides for a continually changing acceleration of said drive ram.

7. The power injector of any of claims 2-5, wherein at least part of said ramp-up profile provides for a non-linear velocity increase of said drive ram.

8. The power injector of any of claims 1 and 3-7, wherein a first part of said ramp-up profile accelerates said drive ram at a first acceleration rate, and wherein a second part of said ramp-up profile accelerates said drive ram at a first acceleration rate that is different from said first acceleration rate.

9. The power injector of any of claims 2 and 8, wherein said first part precedes said second part, 5 and wherein said second acceleration rate is less than said first acceleration rate.

10. The power injector of claim 3, wherein said ramp-up profile is configured to provide a linear velocity increase for said drive ram.

11. The power injector of claim 3, wherein said ramp-up profile is disposable in each of active and deactivated states.

10 12. The power injector of any of claims 1 , 2, and 4-9, wherein said ramp-up profile is disposable in each of active and deactivated states.

13. The power injector of claim 12, wherein activation of said ramp-up profile allows said ramp-up profile to control said input signal to said motorized drive source to advance said drive ram from said stationary state to said initial velocity that is associated with said initial flow rate, and wherein said ramp-up profile is automatically

] 5 activated when said initial flow rate satisfies a predetermined threshold flow rate.

14. The power injector of any of claims 1, 2, and 4-9, wherein operation of said ramp-up profile is required when said initial flow rate satisfies a predetermined threshold flow rate.

15. The power injector of any of claims 3 and 14, wherein said ramp-up profile is disabled when said initial flow rate fails to satisfy said predetermined threshold flow rate

0 16. The power injector of any of claims 1-15, further comprising a syringe installed on said power injector, and a tubing set interconnected with said syringe, wherein said ramp-up profile accounts for a spring constant of each of said syringe and said tubing set.

17. A power injector comprising:

a motorized drive source;

5 an axially movable drive ram operatively interconnected with said motorized drive source;

a first user input device; and

power injector control logic comprising an injection protocol, a first ramp-up profile, and a second ramp-up profile, wherein said injection protocol comprises an initial flow rate, wherein each of said first and second ramp-up profiles contra! an input signal to said motorized drive source to advance said drive ram from a stationary state to an0 initial velocity that is associated with said initial flow rate, wherein said first and second ramp-up profiles are different, and wherein each of said first and second ramp-up profiles are selectable through said first user input device.

18. The power injector of claim 17, wherein said first ramp-up profiles comprises the ramp-up profile from the power injector of any of claims 1-16.

19. The power injector of any of ciaims 17-18, wherein said second ramp-up profiles comprises the ramp-up profile from the power injector of any of claims 1-16.