Systems and methods for detecting air in a fluid injector

Abstract

An injector system for delivering a medical fluid can include at least one syringe defining a reservoir operably connected to a piston; and at least one processor programmed or configured to: determine a baseline value including baseline compressibility data for the at least one syringe of the injector system based on an air check protocol to detect air in the reservoir; perform an air check pressurization sequence by delivering a first quantity of the medical fluid from the reservoir and refilling the reservoir with a second quantity of the medical fluid based on the air check protocol; and compare the air check compressibility data to the baseline compressibility data to determine an amount of air present in the reservoir based on the air check protocol.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 62 / 659,988, filed April 19, 2018, and U.S. Provisional Patent Application No. 62 / 723,711, filed August 28, 2018, the disclosures of which are incorporated herein by reference in their entireties.

[0002] The present disclosure relates generally to systems and methods for detecting and removing air in fluid injectors and fluid reservoirs, and more particularly to systems and methods for detecting and removing air in a fluid reservoir or fluid injector to determine whether the fluid reservoir is filled with medical fluid prior to a fluid injection procedure. [Background technology]

[0003] In many medical diagnostic and therapeutic procedures, medical practitioners, such as physicians or radiologists, use powered fluid injectors to inject one or more medical fluids into a patient. In recent years, several injector-driven syringes and powered fluid injectors for injecting medical fluids under pressure, such as contrast media solutions (often simply referred to as "contrast media"), flushing agents such as saline, and other medical fluids, have been developed for use in procedures such as angiography, computed tomography (CT), ultrasound, magnetic resonance imaging (MRI), positron emission tomography (PET), and other imaging methods. Generally, these fluid injectors are designed to deliver a preset volume of fluid at a preset pressure and / or flow rate to highlight a particular organ or body part in the imaging process or to ensure complete injection of a bolus of contrast media with a flushing agent.

[0004] Typically, a powered injector has a piston connected to a syringe plunger in a fluid reservoir, such as a syringe. The syringe generally includes a rigid body within which the syringe plunger is slidably disposed. The piston drives the plunger proximally and / or distally relative to the longitudinal axis of the body to draw fluid into or expel fluid from the syringe body. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2016 / 112163 Brochure [Patent Document 2] International Publication No. 2015 / 106107 Brochure [Patent Document 3] U.S. Patent No. 5,383,858 [Patent Document 4] U.S. Patent No. 7,553,294 [Patent Document 5] U.S. Patent No. 7,563,249 [Patent Document 6] U.S. Patent No. 7,666,169 [Patent Document 7] U.S. Patent No. 8,945,051 [Patent Document 8] U.S. Patent No. 9,173,995 [Patent Document 9] U.S. Patent No. 9,199,033 [Patent Document 10] U.S. Patent No. 9,474,857 [Patent Document 11] U.S. Patent No. 10,124,110 [Patent Document 12] International Publication No. 2016 / 191485 Brochure [Patent Document 13] International Publication No. 2016 / 112163 Brochure [Patent Document 14] International Publication No. 2016 / 172467 Brochure [Patent Document 15] International Publication No. 2015 / 164783 Brochure Summary of the Invention [Problem to be solved by the invention]

[0006] When drawing medical fluid into a syringe, it is important that the syringe is completely filled with medical fluid and that air is removed from the syringe to avoid unintentional injection of air into a patient. In certain procedures, even small amounts of air can cause concerns if injected into the vascular system during the injection procedure, and in certain imaging procedures, such as angiography, even small amounts of air can lead to complications. Therefore, it is desirable to develop improved systems and methods for detecting air in fluid injectors and fluid reservoirs. [Means for solving the problem]

[0007] In light of the above-mentioned needs, systems and methods are provided for detecting and removing air in fluid injectors and closed fluid reservoirs. Specifically, the present application relates to systems and methods for detecting and removing air in at least a portion of a fluid pathway or tubing, such as a fluid injector and fluid reservoir and / or syringe, that may be fluidly isolated from the fluid pathway by a stopcock or other mechanism, to determine prior to a fluid injection procedure whether a fluid reservoir filled with medical fluid may also contain an unacceptable amount of air or gas.

[0008] In some examples of the present disclosure, an injector system for delivering a medical fluid includes at least one syringe defining a reservoir operably connected to a piston element, the at least one syringe including a plunger, at least one port in communication with the reservoir, and at least a portion of an optional fluid path or set of tubing, the reservoir configured to contain the medical fluid; and determining a baseline value, including baseline compressibility data, for the at least one syringe and associated components of the injector system based on an air check protocol for detecting air in the reservoir, the baseline value including baseline compressibility data for the at least one syringe and associated components of the injector system, the reservoir having a known amount of air. and at least one processor programmed or configured to: perform an air check pressurization sequence by substantially filling the reservoir with medical fluid, delivering a known amount of air and at least a portion of the first quantity of medical fluid from the reservoir, refilling the reservoir with a second quantity of medical fluid, the second quantity of medical fluid may have an unknown amount of air, collecting air check compressibility data for the second quantity of medical fluid and at least one syringe of the injector system based on an air check protocol, and comparing the air check compressibility data for the second quantity of medical fluid with baseline compressibility data to determine the unknown amount of air present in the reservoir based on the air check protocol.

[0009] In another example of the present disclosure, the baseline value can be determined to account for deflections of one or more components of the injector system, compliance of at least a portion of the reservoir and optional fluid path or tubing, and a known amount of air. The processor can be further programmed or configured to purge air in the first quantity of medical fluid from the reservoir based on an air check protocol before determining the baseline value. The processor can be further programmed or configured to incorporate at least one correction factor into the algorithm when comparing the air check compressibility data with the baseline compressibility data based on the air check protocol to account for variations in at least one of deflections of one or more injector system components and / or compliance of the fluid reservoir, a different volume of medical fluid compared to the volume of the first quantity of medical fluid for the baseline compressibility data, and a different piston position compared to the piston position for the baseline compressibility data. The processor can be further programmed or configured to deliver a prime volume of the second quantity of medical fluid from the reservoir based on the air check protocol, the prime volume of the second quantity of medical fluid having a volume greater than the volume of air present in the reservoir. The step of the processor being further programmed or configured to deliver a prime amount of the second quantity of medical fluid can further include optimizing the prime amount to be equal to the minimum amount of the second quantity of medical fluid necessary to remove the amount of air present in the reservoir from the fluid path or set of tubing between the fluid reservoir and the outlet. The processor can be further programmed or configured to determine, based on an air check protocol, whether the amount of air present in the reservoir exceeds a predetermined volume value. If the amount of air present in the reservoir exceeds the predetermined volume value, the processor can be further programmed or configured, based on the air check protocol, to purge the amount of air from the reservoir before delivering the second quantity of medical fluid from the reservoir and / or determine whether a fault condition exists.After purging the amount of air from the reservoir, the processor can be further programmed or configured to perform an additional air check pressurization sequence by collecting additional air check compressibility data from the reservoir, for example, for a third or additional amount of medical fluid, based on the air check protocol, and comparing the additional air check compressibility data with the baseline compressibility data to determine whether any air remains in the reservoir. The predetermined volume value can be in the range of 0.1 mL to 20 mL. Comparing the air check compressibility data with the baseline compressibility data to determine the amount of air present in the reservoir can include using a built-in algorithm to compare the air check compressibility data with the baseline compressibility data to determine the amount of air present in the reservoir. According to certain embodiments, the system can include a downstream detector, such as a downstream air detector, which can be programmed or configured to verify that no air is present in the prime amount delivered from the reservoir of the second amount of medical fluid. The at least one syringe can further include at least one valve associated with the at least one port or outlet or fluid path or tubing set, and the at least one valve can be configured to move between a fill position, a delivery position, and a closed position in response to one or more instructions from the at least one processor. The at least one valve can be positioned in the closed position for at least one of determining baseline compressibility data and performing an air check pressurization sequence.

[0010] In another example of the present disclosure, a method for detecting air in a reservoir may include determining a baseline value including baseline compressibility data for a fluid injector system including at least one fluid reservoir having at least one fluid port and an optional set of fluid paths or tubing, wherein the at least one reservoir is substantially filled with a first quantity of medical fluid having a known amount of air; delivering the first quantity of medical fluid from the at least one reservoir; refilling the at least one reservoir with a second quantity of medical fluid; performing an air check pressurization sequence including pressurizing the second quantity of medical fluid in the at least one reservoir and collecting air check compressibility data; and comparing the air check compressibility data to the baseline compressibility data to determine the amount of air present in the at least one reservoir.

[0011] In another example of the present disclosure, determining the baseline value can include taking into account deflections of one or more components of the fluid injection system, compliance of at least one reservoir and fluid path or tubing set, and a known amount of air. The method can include purging the known amount of air from the at least one reservoir prior to determining the baseline value. The method can include incorporating at least one correction factor into an algorithm when comparing the air check compressibility data to the baseline compressibility data to account for variations in at least one of deflections of one or more fluid injector system components and / or compliance of the fluid reservoir, a different volume of medical fluid compared to a volume of the first quantity of medical fluid for the baseline compressibility data, and a different position of a piston in the fluid injector system compared to a position of a piston for the baseline compressibility data. The method can include delivering a prime amount of the second quantity of medical fluid from the at least one reservoir, the prime amount of the second quantity of medical fluid having a volume greater than a volume of air present in the at least one reservoir. The step of delivering a prime amount of the second quantity of medical fluid can include optimizing the prime amount to be equal to the minimum amount of the second quantity of medical fluid required to remove an amount of air present in the at least one reservoir from a fluid pathway or set of tubing between the fluid reservoir and the outlet. The method can include determining whether a fault condition exists when the amount of air present in the at least one reservoir exceeds a specified amount. The method can include closing a fluid pathway associated with at least one fluid inlet / outlet of the at least one reservoir prior to at least one of determining a baseline value and performing an air check pressurization sequence. The second quantity of medical fluid can be different from the first quantity of medical fluid.

[0012] Various other aspects of the disclosure are described in one or more of the following clauses.

[0013] Clause 1: An injector system for delivering a medical fluid, comprising: at least one syringe defining a reservoir operably connected to a piston, the at least one syringe having a plunger and at least one port in communication with the reservoir, the reservoir configured to contain the medical fluid; and at least one processor programmed or configured to: determine a baseline value including baseline compressibility data for the at least one syringe of the injector system based on an air check protocol to detect air in the reservoir; perform an air check pressurization sequence by substantially filling the reservoir with a first quantity of medical fluid having a known amount of air, delivering the first quantity of medical fluid from the reservoir, and refilling the reservoir with a second quantity of medical fluid based on the air check protocol, and collect air check compressibility data for the at least one syringe of the injector system based on the air check protocol; and compare the air check compressibility data with the baseline compressibility data to determine the amount of air present in the reservoir based on the air check protocol.

[0014] Clause 2: The injector system of clause 1, wherein the baseline value is determined to account for deflection of one or more components of the injector system, compliance of the reservoir and fluid path, and a known amount of air.

[0015] Clause 3: An injector system as described in clause 1 or 2, wherein the processor is further programmed or configured to purge air within the first quantity of medical fluid from the reservoir prior to determining the baseline value based on an air check protocol.

[0016] Clause 4: An injector system as described in any one of clauses 1 to 3, wherein the processor is further programmed or configured to incorporate a correction factor when comparing the air check compressibility data with the baseline compressibility data to account for variations in at least one of deflection of one or more injector system components, a volume of medical fluid that differs compared to the volume of the first amount of medical fluid for the baseline compressibility data, and a piston position that differs compared to the piston position for the baseline compressibility data, based on an air check protocol.

[0017] Clause 5: An injector system described in any one of clauses 1 to 4, wherein the processor is further programmed or configured to deliver a prime amount of the second quantity of medical fluid from the reservoir based on an air check protocol, the prime amount of the second quantity of medical fluid having a volume greater than the volume of air present in the reservoir.

[0018] Clause 6: The injector system described in Clause 5, wherein the step in which the processor is further programmed or configured to deliver a prime amount of the second quantity of medical fluid further includes optimizing the prime amount to be equal to the minimum amount of the second quantity of medical fluid required to remove the amount of air present in the reservoir.

[0019] Clause 7: An injector system described in any one of clauses 1 to 6, wherein the processor is further programmed or configured to determine, based on an air check protocol, whether the amount of air present in the reservoir exceeds a predetermined volume value.

[0020] Clause 8: An injector system as described in Clause 7, wherein if the amount of air present in the reservoir exceeds a predetermined volume value, the processor is further programmed or configured to purge the amount of air from the reservoir before delivering a second amount of medical fluid from the reservoir based on an air check protocol, or to determine whether a fault condition exists.

[0021] Clause 9: The injector system of clause 8, wherein after purging the amount of air from the reservoir, the processor is further programmed or configured to perform an additional air check pressurization sequence by collecting additional air check compressibility data from the reservoir based on the air check protocol, and comparing the additional air check compressibility data with the baseline compressibility data to determine whether any air remains in the reservoir.

[0022] Clause 10: The injector system of clause 7, wherein the predetermined volume value is in the range of 0.1 milliliters to 20 milliliters.

[0023] Clause 11: An injector system as described in any one of clauses 1 to 10, wherein comparing the air check compressibility data with baseline compressibility data to determine the amount of air present in the reservoir includes using a built-in algorithm to compare the air check compressibility data with baseline compressibility data to determine the amount of air present in the reservoir.

[0024] Clause 12: An injector system as described in any one of clauses 5 to 11, further comprising a downstream air detector, the downstream air detector programmed or configured to verify that no air is present in a prime quantity of the second quantity of medical fluid delivered from the reservoir.

[0025] Clause 13: An injector system described in any one of clauses 1 to 12, wherein at least one syringe includes at least one valve associated with at least one port and outlet, and the at least one valve is configured to move between a filling position, a delivery position, and a closed position in response to one or more instructions from at least one processor.

[0026] Clause 14: The injector system of clause 13, wherein at least one valve is in a closed position for at least one of determining baseline compressibility data and performing an air check pressurization sequence.

[0027] Clause 15: A method for detecting air in a reservoir, the method comprising: determining a baseline value including baseline compressibility data for a fluid injector system having at least one reservoir having at least one fluid inlet and outlet, the at least one reservoir being substantially filled with a first quantity of medical fluid having a known amount of air; delivering the first quantity of medical fluid from the at least one reservoir; refilling the at least one reservoir with a second quantity of medical fluid; performing an air check pressurization sequence including pressurizing the medical fluid in the at least one reservoir and collecting air check compressibility data; and comparing the air check compressibility data to the baseline compressibility data to determine the amount of air present in the at least one reservoir.

[0028] Clause 16: The method of clause 15, wherein determining the baseline value includes taking into account deflection of the fluid injection system, compliance of at least one reservoir and fluid path, and a known amount of air.

[0029] Clause 17: The method of clause 15 or 16, further comprising purging a known amount of air from at least one reservoir prior to determining the baseline value.

[0030] Clause 18: The method of any one of clauses 15 to 17, further comprising incorporating a correction factor when comparing the air check compressibility data with the baseline compressibility data to account for variations in at least one of deflection of one or more fluid injector system components, a volume of medical fluid that differs compared to the volume of the first amount of medical fluid for the baseline compressibility data, and a position of the piston that differs compared to the position of the piston in the fluid injector system for the baseline compressibility data.

[0031] Clause 19: The method of any one of clauses 15 to 18, further comprising the step of delivering a prime amount of the second quantity of medical fluid from at least one reservoir, the prime amount of the second quantity of medical fluid having a volume greater than the volume of air present in the at least one reservoir.

[0032] Clause 20: The method of clause 19, wherein the step of delivering a prime amount of the second quantity of medical fluid further includes a step of optimizing the prime amount to be equal to the minimum amount of the second quantity of medical fluid required to remove the amount of air present in at least one reservoir.

[0033] Clause 21: The method of any one of clauses 15 to 20, further comprising determining whether a fault condition exists when the amount of air present in at least one reservoir exceeds a specified amount.

[0034] Clause 22: A method according to any one of clauses 15 to 21, further comprising the step of closing a fluid path associated with at least one fluid inlet / outlet of at least one reservoir prior to at least one of the steps of determining a baseline value and performing an air check pressurization sequence.

[0035] Clause 23: The method of any one of clauses 15 to 22, wherein the second quantity of medical fluid is different from the first quantity of medical fluid.

[0036] Further details and advantages of the various examples detailed herein will become apparent from the following detailed description of the various examples, taken in conjunction with the accompanying drawing figures. [Brief explanation of the drawings]

[0037] [Figure 1] 1 is a perspective view of a fluid injector according to one aspect of the present disclosure configured to use a multi-fluid delivery system; [Figure 2] FIG. 2 is a perspective view of a multi-fluid delivery system for use with the fluid injector of FIG. 1. [Figure 3] 2 is a perspective view of the multi-fluid delivery system as it is inserted into a receiving slot of the fluid injector of FIG. 1. [Figure 4A] FIG. 1 is a schematic view of a syringe according to the present disclosure with a purge port in an open position. [Figure 4B] FIG. 4B is a schematic diagram of the syringe of FIG. 4A with the purge port closed. [Figure 4C] 1 is a graphical representation of baseline compressibility data obtained during the air check protocol of the present disclosure. [Figure 4D] FIG. 4B is a schematic diagram of the syringe of FIG. 4A with the injection port in an open position. [Figure 4E] FIG. 4B is a schematic diagram of the syringe of FIG. 4A with the injection port in a closed position. [Figure 4F] 1 is a graphical representation of baseline compressibility data and air check compressibility data obtained in the air check protocol of the present disclosure. [Figure 5] FIG. 1 is a schematic diagram of a baseline compressible data sequence for an air check protocol. [Figure 6] FIG. 10 is a schematic diagram of an air check compressible data sequence of the air check protocol. [Figure 7] 1 is a graphical representation of the correction factors used in the air check protocol of the present disclosure. [Figure 8] 1 is a graphical representation of pressure versus displacement for various different motors. [Figure 9] 1 is a graphical representation of pressure versus displacement values ​​obtained at different locations. DETAILED DESCRIPTION OF THE INVENTION

[0038] In Figures 1-9, like numbers refer to the same components and elements in some cases, unless otherwise specified.

[0039] As used herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Spatial or directional terms, such as "left," "right," "inside," "outside," "top," "bottom," and the like, relate to each feature of the present disclosure as shown in the drawing figures and should not be considered limiting, as various features may assume a variety of different orientations. All numbers used in this specification and claims should be understood to be modified in all instances by the term "about." "About" means plus or minus 25 percent of the stated value, such as plus or minus 10 percent of the stated value. However, this should not be considered as limiting the analysis of values ​​under the doctrine of equivalents.

[0040] Unless otherwise indicated, all ranges or ratios disclosed herein should be understood to encompass the beginning and ending values, and any and all subranges or subratios contained within that range or ratio. For example, describing a range "1 to 10" or a ratio "1 to 10" should be understood to include any and all subranges or subratios between (and including) the minimum value of 1 and the maximum value of 10, i.e., all subranges or subratios beginning with a minimum value of 1 or greater and ending with a maximum value of 10 or less. Ranges and / or ratios disclosed herein represent average values ​​within the specified range and / or ratio.

[0041] The terms "first...", "second...", etc. are not intended to refer to a particular order or sequence, but rather to separate states, properties, or elements. The term "at least..." is synonymous with "greater than or equal to...". The term "not more than..." is synonymous with "less than or equal to...". All documents referenced herein are "incorporated by reference" in their entirety.

[0042] As used herein, "at least one of" is synonymous with "one or more of." For example, the phrase "at least one of A, B, and C" means any one of A, B, or C, or any combination of any two or more of A, B, or C. For example, "at least one of A, B, and C" includes A only, B only, C only, A and B, A and C, B and C, or all of A, B, and C. The term "including" is synonymous with "comprising."

[0043] For example, when used in reference to a syringe in a multi-purpose disposable set (MUDS), the term "proximal" refers to the portion of the syringe closest to the piston element for expelling fluid from the syringe. When used in reference to a fluid pathway, the term "proximal" refers to the portion of the fluid pathway closest to the injector system when the fluid pathway is connected to the injector system. When used in reference to a syringe, the term "distal" refers to the portion of the syringe closest to the delivery nozzle. When used in reference to a fluid pathway, the term "distal" refers to the portion of the fluid pathway closest to the user when the fluid pathway is connected to the injector system. The term "radial" refers to a direction in a cross section perpendicular to the longitudinal axis of the syringe extending between the proximal and distal ends. The term "circumferential" refers to a direction around the inner or outer surface of the sidewall of the syringe. The term "axial" refers to a direction along the longitudinal axis of the syringe extending between the proximal and distal ends.

[0044] As used herein, the term "reservoir" or "fluid reservoir" includes at least a portion of a fluid pathway, such as a syringe, container, or set of tubing. Any type of reservoir capable of applying force or displacement can be utilized in the air detection methods described herein. The term "open," when used in reference to a fluid delivery component, means that the system is in communication with an outlet, for example, through a nozzle or open end of a fluid pathway, tubing component, or catheter. In an open system, fluid flow may be restricted, for example, by forcing the fluid through a small-diameter fluid pathway, where flow may be determined by physical parameters of the system and the fluid, such as the diameter of the tubing, the restriction in the fluid pathway, the applied pressure, and viscosity. The term "closed," when used in reference to a fluid delivery component, means that the system is not in communication with or is fluidically isolated from the outlet, for example, by preventing fluid flow with a valve, such as a stopcock, high-crack pressure valve, pinch valve, one-way valve, or the like. As used herein, the term "sag" refers to mechanical slack, such as clearance or lost motion in a mechanism caused by gaps between parts and / or compression and / or deflection of one or more mechanical components due to the application of a load (e.g., by the application of pressure), resulting in a delay in the delivery of pressurized fluid from fluid injection after the application of force. The reservoir in this context depends on where the system is closed. As used herein, the terms "compliance" or "capacitance" refer to the increase in volume of a fluid reservoir, fluid pathway, or set of tubing, in either a closed or open system, when the fluid contained therein is placed under pressure causing an increase in internal volume.

[0045] It should be understood, however, that the present disclosure may embody other variations and step sequences unless expressly stated otherwise. It should also be understood that the specific devices and processes illustrated in the accompanying drawings, and described in the following specification, are merely exemplary embodiments of the present disclosure. Hence, specific dimensions and other physical characteristics related to the examples disclosed herein are not to be considered limiting.

[0046] The present disclosure describes systems and methods for detecting both small amounts of air, e.g., in the range of 0.1 mL to 1.0 mL, and large amounts of air, including when a syringe is completely filled with air, such as when there is a problem in the syringe filling process, thereby reducing the likelihood that air may be accidentally injected into a patient during a medical procedure, such as injection of contrast and / or saline prior to a contrast imaging procedure. The methods of the present disclosure may be performed after user initiation or may be performed automatically by a processor in the fluid injector when the injector is primed for one or more fluid injection protocols.

[0047] Referring to the drawings, wherein like reference numerals refer to like parts throughout the several views of the drawings, the present disclosure generally relates to a medical injector / injection system 100 (hereinafter "fluid injector system 100"), such as an injector system including one or more syringes, e.g., front-loading syringes and rolling diaphragm syringes. The present disclosure is described according to an embodiment to the fluid injector system 100 in the form of a multi-fluid injector system having a MUDS 130 (shown in FIG. 2) configured to provide fluid to a patient using a fluid pathway, e.g., a set of tubing and / or a manifold. However, various methods and protocols of the present disclosure can be utilized or adapted to other syringe-based injector systems.

[0048] Fluid injector system 100 includes a number of components, as individually described herein. Generally, fluid injector system 100 includes a powered injector management apparatus or device intended to be combined with an injector to deliver one or more fluids under pressure from one or more fluid reservoirs to a patient, as described herein, and a fluid delivery set. Various devices, components, and features of fluid injector system 100 and a fluid delivery set combined with the fluid injector system are also described in detail herein, according to one embodiment. In one example, MUDS 130 is disclosed in U.S. Patent No. 6,244,999, and an example of a SUDS is described in U.S. Patent No. 6,244,999, both of which are incorporated herein by reference in their entireties. The air detection method, described in detail below, can be initiated upon initial installation of MUDS 130 and / or repeated each time one or more of the fluid reservoirs within MUDS 130 are filled over a series of injection procedures or the useful life of MUDS 130.

[0049] In other examples, the methods of the present disclosure may be suitable for use in single or dual syringe front-loading fluid injector systems as disclosed, for example, in U.S. Patent Nos. 5,611,149, 5,611,152, 5,611,153, 5,611,154, 5,611,155, 5,611,156, 5,611,157 ...

[0050] 1 , fluid injector system 100 includes an injector housing 102 having opposing sides 104, a distal or upper end 106, and a proximal or lower end 108. Housing 102 houses various mechanical drive components, electrical and power components necessary to drive the mechanical drive components, and control components (hereinafter, electronic control devices) such as electronic memory and electronic control devices used to control the operation of a reciprocable piston element associated with fluid injector system 100 described herein. Such piston elements may be reciprocally movable via electromechanical drive components such as a ball screw shaft driven by a motor, a voice coil actuator, a rack and pinion gear drive, a linear motor, or the like. In some embodiments, at least some of the mechanical drive components, electrical and power components, and control components may be provided on a base 110.

[0051] The fluid injector system 100 further includes at least one bulk fluid connector 118 for connection to at least one bulk fluid source 120. In some embodiments, multiple bulk fluid connectors 118 can be provided. The at least one bulk fluid source 120 can be configured to receive a medical fluid, such as saline, contrast, or other medical fluid, for delivery to the fluid injector system 100. The housing 102 can have at least one support member 122 for supporting the at least one bulk fluid source 120 when connected to the fluid injector system 100.

[0052] 1 , the fluid injector system 100 includes one or more user interfaces 124, such as a graphical user interface (GUI) display window. The user interface 124 can display information related to a fluid injection procedure involving the fluid injector system 100, such as the current flow rate, fluid pressure, and volume remaining in at least one bulk fluid source 120 connected to the fluid injector system 100, and can present information about air present in one or more reservoirs as determined by various methods and protocols described herein. In certain embodiments, the one or more user interfaces 124 can be a touchscreen GUI that allows an operator to input commands and / or data for operation of the fluid injector system 100. While the user interface 124 is shown on the injector housing 102, the interface 124 can also be in the form of or include an additional remote display that is wired or wirelessly linked to the housing 102 and control and mechanical elements of the fluid injector system 100. In some embodiments, the user interface 124 may be a tablet computer that is removably connected to the housing 102 and that is linked and communicates with the housing 102 via a wired or wireless link. The fluid injector system 100 may further include one or more processors configured to electronically communicate with the fluid injector system 100 and control one or more functions of the fluid injector system 100, such as, for example, any of the steps of the air detection methods described herein. Additionally, the fluid injector system 100 and / or the user interface 124 may include at least one control button 126 for tactile operation by an attending operator of the fluid injector system 100. In certain embodiments, the at least one control button 126 may be part of a keyboard for entry of commands and / or data by the operator.The at least one control button 126 may be hardwired or wirelessly connected to one or more electronic control devices associated with the fluid injector system 100 to provide direct input to the electronic control device. The at least one control button 126 may also be a graphical portion of the user interface 124, such as a touchscreen. In either configuration, the at least one control button 126 desirably provides a specific, individual control function to an attending operator of the fluid injector system 100, such as, but not limited to, (1) acknowledging the loading or unloading of multiple patient disposable sets, (2) initiating and providing information regarding air detection methods according to various embodiments herein, (3) filling / purging the fluid injector system 100, (4) inputting information and / or data regarding the patient and / or injection procedure, and (5) starting / stopping an injection procedure. The user interface 124 and / or any electronic processing unit associated with the fluid injector system 100 may be connected, either wired or wirelessly, to an operational and / or data storage system, such as a hospital network system.

[0053] Referring to FIG. 2, the MUDS 130 may include a frame 154 for supporting one or more syringes 132. The syringes 132 may be removably or permanently connected to the frame 154. Referring to FIGS. 4A-4B, each syringe 132 may have an elongated, substantially cylindrical syringe body 138 having a front or distal end 140 and a rear or proximal end 142. A syringe plunger 144 is disposed within the syringe body 138 and is reciprocally movable within the syringe body 138 in response to movement of a piston element associated with the fluid injector system 100. The distal end 140 of the syringe body 138 may be generally conical and tapered to an apex or conical point 145. The syringe apex or conical point 145 is located along the central longitudinal axis L of the syringe body 138.

[0054] 4A, 4B, 4D, and 4F, each syringe 132 can have a fill port 147 in communication with a fluid pathway 134 for filling the syringe interior 139 with fluid from a bulk fluid source 120 (shown in FIG. 2). Each syringe 132 can further have a discharge outlet 146 at the end of an apex or conical point 145. The discharge outlet 146 of each syringe 132 is in communication with a manifold 148 (shown in FIG. 2). In some embodiments, the manifold 148 can fluidly connect multiple syringes 132. Communication between the syringe interior 139 and the fluid pathway 134 and manifold 148 can be controlled by a valve 136 at the distal end 140 of the syringe 132. A pump 149, such as a piston element for reciprocating the plunger 144, can be releasably attached to the plunger 144 of the syringe 132 to selectively draw medical fluid through a fill port 147 or expel medical fluid and / or gas through an outlet 146 of the syringe 132. In certain embodiments, the manifold 148 can also provide support for the syringes 132 so that the syringes 132 can be handled as a single, integral structure. In some embodiments, the manifold 148 supports the distal end 140 of each syringe 132, while the frame 154 supports the proximal end 142 of each syringe 132. In some embodiments, at least a portion of the manifold 148 can be integrally formed with at least one syringe 132, for example, by a suitable adhesive or welding. The syringes 132 can be arranged in a side-by-side orientation or in any other orientation that preserves the relative arrangement of the syringes 132.

[0055] Referring to FIG. 3, another embodiment of a MUDS 130 is shown. The MUDS 130 can include multiple syringes 132, side-by-side or in other arrangements, each of which can be in communication with one of the bulk fluid sources 120 (shown in FIG. 2). Each of the syringes 132 can be in communication with a manifold 148. The manifold 148 can connect the syringes 132 together. The manifold 148 can have a fluid path in communication with each of the syringes 132. The fluid path can be in communication with one or more fluid outlet lines 152 (shown in FIG. 2). A valve 136 can be provided on each fluid fill line 150 extending from the bulk fluid source 120 to a fill port 147 of the syringe 132 for filling the syringe 132 with fluid from the bulk fluid source 120. According to various embodiments, at least a portion of valve 136 may be rotatable, for example, about the longitudinal axis L of each respective syringe 132. Valve 136 may be operable between a fill position for filling syringe 132 with fluid, a delivery position for delivering fluid from syringe 132, and a closed position for blocking fluid from entering or leaving syringe 132. In some embodiments, valve 136 may be rotatable between a first position in which fill port 147 is in communication with syringe 132 while discharge outlet 146 is fluidly isolated from syringe 132, and a second position in which discharge outlet 146 is in communication with syringe 132 while fill port 147 is fluidly isolated from the syringe interior. Valve 136 may have a third position in which the interior of syringe 132 is isolated from both fill port 147 and discharge outlet 146. In a first position, valve 136 can be configured to allow syringe 132 to fill with fluid from bulk fluid source 120 via fluid pathway 134 while preventing delivery of fluid to manifold 148. In a second position, valve 136 can be configured to allow fluid to be delivered from syringe 132 through discharge outlet 146 to manifold 148 while preventing delivery of fluid through fill port 147.Valve 136 can be configured to fluidly isolate the interior of the fluid reservoir, e.g., by blocking fluid flow through fill port 147 and discharge outlet 146 so that fluid cannot enter or exit syringe 132. In some embodiments, valve 136 can be rotatable to partially open or partially close discharge outlet 146 and / or fill port 147. In various embodiments, valve 136 of each syringe 132 can be controlled independently of one another, e.g., to allow different medical fluids to be delivered to one or more syringes 132 and / or delivered simultaneously or sequentially from one or more other syringes 132. Valves 136 of multiple syringes 132 can be controlled, e.g., via one or more electronic control devices or processors associated with fluid injector system 100. Valves 136 can be stopcocks, high crack pressure valves, pinch valves, one-way valves, or any similar type of valve.

[0056] 2, MUDS 130 is removably connectable to housing 102 of fluid injector system 100. As will be appreciated by those skilled in the art, it may be desirable to fabricate at least a portion of MUDS 130 from a clear, medical-grade plastic to facilitate visual verification of the establishment of communication with fluid injector system 100. Visual verification may also be desirable to confirm the absence of air bubbles within the various fluid connections, for example, to ensure that no air remains in the syringe or fluid path after an air detection and priming sequence. Alternatively, at least a portion of MUDS 130 and / or door 116 may include a window (not shown) for visualizing the connections between the various components.

[0057] 2, in some embodiments, fluid outlet line 152 can be further connected to a waste reservoir 156 on fluid injector system 100. Waste reservoir 156 is desirably separate from syringe 132 to prevent contamination. In some embodiments, waste reservoir 156 is configured to receive excess fluid and air expelled from syringe 132 during priming or purging operations, such as after a fluid detection protocol described herein.

[0058] As used herein, an electronic control device includes a processor that executes, or is operable to execute, appropriate custom-designed or conventional software to execute and implement the processing steps of embodiments of the disclosed methods and systems, thereby forming a dedicated and specific computing system. Thus, the disclosed methods and systems may include one or more electronic control devices or similar computing devices having a computer-readable storage medium that can store computer-readable program code or instructions that cause a processing unit to execute, configure, or otherwise implement the data manipulations of the methods, processes, and transformations described below in connection with the present disclosure. Furthermore, the electronic control device may be in the form of a computer, personal digital assistant, portable computer, laptop, palmtop, mobile device, mobile phone, server, or any other type of computing device that has the necessary processing hardware to appropriately process data to effectively implement the computer-implemented methods and systems of the disclosed disclosure. In one example, the electronic control device may house a user interface 124 and a corresponding processor.

[0059] Those skilled in the art will appreciate that the system can utilize databases that are physically located on one or more computers or that are computer-accessible, for example, via the Internet or cloud computing technologies, and that may or may not be the same as the respective servers. For example, programming software on an electronic control device can control a database that is physically stored, such as on another processor on a network, or stored in a local or single location accessible by multiple fluid injection systems. Such a local or single location can allow for easy updating of information and data stored therein and accessible by processors associated with multiple remote fluid injectors.

[0060] In some embodiments, the electronic control device can be programmed to automatically refill based on a preprogrammed minimum trigger volume in each syringe 132. For example, a syringe refill procedure can be automatically initiated by the electronic control device when the amount of fluid remaining in at least one of the syringes 132 is less than a programmed amount. The electronic control device associated with the fluid injector system 100 can determine when the preprogrammed minimum trigger volume has been reached by tracking the fluid volume delivered from each syringe 132 during operation of the fluid injector system 100. Alternatively, fluid level sensors can be incorporated into the fluid injector system 100, and input from these fluid level sensors can be provided to the electronic control device to determine when the preprogrammed minimum trigger volume has been reached in at least one of the syringes 132. The fill volume and refill rate can be preprogrammed into the electronic control device. The automatic refill procedure can be automatically stopped by the electronic control device or can be manually interrupted. Furthermore, upon completion of a fluid injection procedure, an automatic refill procedure can be initiated if at least one of the syringes 132 does not have enough fluid to perform the next programmed fluid injection procedure. During a refill procedure, one or more of the bulk fluid sources 120 associated with each syringe 132 may become empty (e.g., there may not initially be enough fluid to complete a full refill of one or more syringes 132). The fluid injector system 100 can have an indicator, such as an audible and / or visual indicator, to notify the operator that a bulk fluid source 120 needs to be changed before using the fluid injector system 100. According to various embodiments, the air detection methods and protocols described herein can be performed for each fluid reservoir or syringe each time the fluid reservoir or syringe is refilled with medical fluid to determine whether air has been introduced into the fluid reservoir with the refilled fluid.

[0061] 4A-7, methods and programs for detecting air in a fluid reservoir by an electronic control device according to various embodiments, initiated by the electronic control device according to various embodiments, are described in detail. Non-limiting example sequences for various specific methods 500, 600 are shown in FIGS. 5 and 6. In a first stage of the method, an initial baseline value can be determined for at least one of the syringes 132. It should be understood that baseline values ​​can be determined for one, at least two, or all of the syringes 132 used in the fluid injector system 100. Referring to FIG. 5, according to one example, a baseline value is determined for one syringe 132. In this initial stage, the syringe 132 is installed in the fluid injector system 100, and medical fluid from a bulk fluid source 120 can be directed to the syringe 132, for example, via fluid paths and valves fluidly connecting the bulk fluid source 120 to the syringe 132. In step 502, the valve 136 of the syringe 132, which in one example may be a stopcock, is moved to a first open position to allow medical fluid to flow from the bulk fluid source 120 into the syringe 132. Then, in step 504, the syringe 132 may be filled to a predetermined volume. In one example, the syringe 132 is filled to a predetermined volume ranging from 50 milliliters to 250 milliliters. In step 506, after the syringe 132 is filled to the predetermined volume, a purge sequence may be initiated to remove any bulk volume of air that may have been drawn into the syringe 132 from the fluid path 134. As shown in FIG. 4A , in one example, the air is purged from the syringe 132 through a purge port on the syringe 132. In another example, the air is purged from the syringe 132 through the distal end of the syringe 132.It should be understood that a purge sequence may be any activity to remove a bulk volume of air from the syringe 132, such as, for example, moving the piston element distally to expel the bulk volume of air back into the bulk fluid source 120, or expelling the bulk volume of air from the syringe 132 through the fluid path to the waste reservoir 156. There may also be situations where there is a “non-injectable” volume of air that does not need to be purged and may become part of the baseline value, provided that it is removed from the reservoir prior to injecting medical fluid into the patient. As shown in FIGS. 4B and 5 , after the air is purged from the syringe 132 in step 508, the syringe 132 may be filled with additional medical fluid until a predetermined volume of medical fluid is retained within the syringe 132. In step 510, the processor may verify that the air has been purged from the system. Alternatively, in certain embodiments where the volume of air present in the fluid reservoir is a known volume, this known amount of air can be incorporated into or taken into account by the algorithm to determine a baseline value that includes baseline compressibility data for the fluid reservoir or syringe that includes data for both the volume of the first amount of medical fluid and the known volume of air.

[0062] Once a baseline value, including baseline compressibility data, is determined for the fluid reservoir or syringe, the piston element of the fluid reservoir or syringe 132 can be moved distally to deliver at least a portion of the first quantity of medical fluid from the reservoir, and a known volume of air, if present, from the fluid reservoir. For example, the piston element of the fluid injector can be moved distally a sufficient amount to expel at least a portion of the first quantity of medical fluid and all of the air from the reservoir through an associated fluid pathway. A detector, such as an air detector, can be used to ensure that all of the known amount of air has been removed from the reservoir. For example, an air detector associated with the fluid pathway can monitor the fluid flowing through the fluid pathway to determine when no more air is detected in the fluid pathway.

[0063] Explaining the determination of the baseline value in more detail, in steps 512 and 514, after the syringe 132 is closed, the syringe 132 and any known amount of air present therein may be pressurized until a target pressure and / or target displacement of a piston element within the syringe 132 is achieved. Pressurization is typically accomplished by moving a piston element associated with the fluid injector distally. In steps 516 and 518, the target pressure or target displacement may be recorded by the electronic control device as baseline compressibility data for the syringe 132. In step 520, the baseline protocol ends. In embodiments in which the syringe reservoir contains a known volume of air along with a first amount of fluid, the air compressibility data associated with the known volume is incorporated into the baseline compressibility data and considered in the calculations for determining the baseline value. As shown in FIG. 4C , in one example, the electronic control device of the fluid injector system 100 may record the target pressure or displacement for the particular syringe 132 being tested. Pump motor, and / or Plunger 144Baseline compressibility data for the motor and piston element of the fluid injector can be recorded. The baseline value can be specific to each motor and piston element of the fluid injector. For example, as shown in FIG. 8, three motors and piston elements of a fluid injector according to one embodiment exhibit different baseline compressibility curves. Furthermore, the baseline value, including the baseline compressibility data of a particular motor, can change over the life of the motor. According to various embodiments, to compensate for changes over time, the baseline value can be determined frequently, for example, each time a new syringe is inserted. The electronic control device can determine the time when the baseline compressibility data was recorded. Plunger 144The position of the syringe 132 may also be recorded. Because different combinations of syringe, motor, and piston elements may have different compressibility data, the fluid injector system 100 is configured to record and save baseline compressibility data for each combination. Furthermore, because compressibility data varies from combination to combination, a protocol for obtaining baseline compressibility data should be initiated each time a new syringe, motor, and / or piston element is replaced in the fluid injector system 100 to ensure the most accurate baseline compressibility data is being used. The pressure value for pressurizing the syringe 132 can be varied as desired by the user of the fluid injector system 100. In one example, the pressure value may range from 5 psi to 300 psi. In a further example, the pressure value used is 1000 kPa, which ensures that noise associated with the fluid injector system 100 is suppressed and a linear region of a stable signal is achieved. After the baseline compressibility data is recorded, the baseline protocol is terminated by the fluid injector system 100. According to certain embodiments of the present method, baseline compressibility data can be obtained according to various procedures. In certain embodiments, the determination or calibration can be performed at least at the following times: a) each time a syringe or fluid path is installed in an injector; b) once for each injector system during manufacturing; and / or c) a global function can be developed that compensates for variations from all injector / reservoir / component combinations, for example, by using statistical evaluation.

[0064] In another example of the present disclosure, baseline compressibility data for the syringe 132 can be established using calculations or previous characterizations of characteristics of the fluid injector system 100, including sag in the system 100, compliance of components of the system 100, and / or previous baseline compressibility data measured for the system 100. According to this embodiment, historical averages of disposable components, such as syringes and / or fluid paths, can be provided to the injector for baseline value calculation, which, combined with specific historical values ​​for a particular injector motor or global historical values ​​for a motor configuration, can result in a global average of baseline compressibility data for a particular configuration of fluid injectors and disposable components, which can be used to determine a global baseline value for the fluid injector / disposable component configuration. While this approach may not be as accurate as determining a baseline value for a particular injector with a particular syringe and / or fluid path, the global value can be sufficiently accurate to allow for calculation and detection of air volume in the syringe. For example, in certain types of injection protocols, such as computed tomography, the average value can provide sufficiently accurate air detection to prevent the injection of undesirable amounts of air. In contrast, in other injection protocols that are more sensitive to air injection, such as angiography, accurate determination of the baseline value may be necessary to ensure that the syringe and fluid pathway are substantially free of air prior to injection of the medical fluid.

[0065] 4D, after the baseline compressibility data has been determined for the fluid injector system 100, the fluid injector system 100 may expel at least a portion of the first volume of medical fluid and a known volume of air, if present, from the syringe 132 prior to the actual injection procedure. The fluid injector system 100 may now be ready for the actual injection procedure with a second volume of medical fluid incorporating methods described herein to detect whether air is present in the fluid reservoir and / or fluid path prior to the actual injection. As shown in FIG. 6, in steps 602 and 604, after the expulsion process, one or more syringes 132 may be refilled with a second amount of medical fluid from the bulk fluid source 120. 4E, after the syringe 132 is filled to a predetermined volume with the second amount of medical fluid, an air check protocol is initiated by the fluid injector system 100 to ensure that no air is present in the syringe 132 and / or the medical fluid held therein in accordance with embodiments of the air detection methods and protocols described herein. In summary, an air check pressurization sequence is performed to collect air check compressibility data from the refilled syringe 132 with the second amount of medical fluid, which values ​​are compared to the baseline compressibility data to determine whether and how much air is present in the syringe 132 and / or the medical fluid contained therein. After the syringe 132 is filled with the second volume of medical fluid, the syringe 132 is closed. For example, the valve 136 or stopcock is closed to isolate the syringe 132. If air is determined to be present based on the air check protocol and the amount of air determined, the air can be removed or vented from the reservoir as described herein.

[0066] In steps 606 and 608, after the syringe 132 is closed, the syringe 132 can be pressurized to a target pressure and / or target displacement of the piston element within the syringe 132. According to certain embodiments, the target pressure and / or target displacement can be the same as those established during the baseline protocol. Alternatively, according to other embodiments, a different target pressure or target volume can be used than that used during the baseline determination, and a correction factor can be incorporated into the calculation to compensate for differences in fluid volume or applied pressure. Next, in step 610, the fluid injector system 100 is configured to compare the air check compressibility data with the baseline compressibility data, for example, by using a comparison algorithm that determines the amount of air present based on the difference between the baseline compressibility data and the air check compressibility data. Then, in step 612, the displacement and pressure of the second amount of medical fluid within the syringe 132 is recorded by the fluid injector system 100 as the air check compressibility data of the syringe 132 in its current refill state. The position of the syringe 132 at the time the air check compressibility data was recorded is stored in the fluid injector system 100. As shown in FIG. 4F and FIG. 6, in step 614, an estimated amount of air present in the syringe 132 is calculated using a stored algorithm stored in the fluid injector system 100 based on the air check compressibility data and the baseline compressibility data recorded by the fluid injector system 100. Upon comparing the air check compressibility data to the baseline compressibility data, the force required to displace and pressurize the second quantity of medical fluid and associated air therein in the syringe 132 during the air check protocol is compared to the force required to displace and pressurize the first quantity of medical fluid in the syringe 132 during the baseline protocol to determine whether air is present in the syringe 132 and / or the second quantity of medical fluid. Air and other gases that may be present in the syringe 132 are significantly more compressible than the medical fluid.Thus, if air is present in the syringe 132 and / or medical fluid, the displacement of the piston element within the syringe 132 will be different in a syringe 132 at least partially filled with air compared to a baseline syringe determined from a first volume of medical fluid and, optionally, a known volume of air. For example, to generate 30 psi of pressure within the syringe 132, the air will compress much more than the medical fluid, which will manifest as an increased piston travel distance compared to a syringe completely filled with medical fluid. If air is present within the syringe 132, the piston element will need to travel further in the pre-compression to reach 30 psi. In the graph shown in FIG. 4F, the presence of air in the syringe 132 or system 100 can be determined from the difference between the baseline compressibility data line and the air check compressibility data line. According to various embodiments, the algorithm for determining the difference between the baseline compressibility data line and the air check compressibility data line can take into account a known amount of air present in the first amount of medical fluid, differences between the piston position and / or fluid volume in the syringe for the first amount of fluid and the second amount of fluid, and differences between the applied pressures at the time the baseline compressibility data line and the air check compressibility data line were determined.

[0067] According to some embodiments, the downstream air detector 153 can be used to train the reservoir air detection algorithm. For example, after completion of the filling procedure, the reservoir can be pressurized to obtain compressibility data as described herein. The delivery of fluid from the reservoir can be monitored by the downstream air detector 153 to provide a measurement of the amount of air in the fluid during a subsequent fluid delivery operation, where the amount of air detected by the downstream air detector 153 during delivery through the fluid path provides a correlation with the resolution or accuracy associated with the reservoir pressurization method. After completion of the fluid delivery operation, the amount of air measured by the reservoir pressurization method described herein can be compared to the amount measured by the downstream air detector 153. To improve the accuracy of the air detection method according to the present disclosure, an equation or correction factor for the reservoir pressurization method can be determined and incorporated into future measurements based on the difference in measurements obtained by the two methods. Using this approach, it is expected that as more measurements are obtained, there will be less reliance on the air detector 153 downstream of the system, which will likely improve the accuracy of the pressurization method over time by using a real-time feedback loop of data to improve the correlation between the air check compressibility data and the amount of air present in the syringe. Thus, according to this embodiment, air detection prior to the start of fluid delivery to the patient may become more reliable over time. According to certain embodiments, real-time training of the pressurization algorithm may occur during manufacture or initial testing of an individual fluid injector system 100 to tailor the air detection to the particular injector. Furthermore, the algorithm may be trained over at least a portion of its lifetime to allow the air detection algorithm to adapt to changes in system behavior over time.

[0068] After the amount of air in the syringe 132 is determined by the fluid injector system 100 in step 620, the determined amount of air is compared to a threshold air amount value to determine whether the fluid injector system 100 can initiate a fluid injection protocol. If the amount of air present in the syringe is determined to be greater than the threshold air amount, an alert can be generated to notify the user of the presence of undesired air in the syringe, and the injection protocol can be aborted. Alternatively, the processor can determine that a fault condition exists, for example, if an amount of air exceeding the threshold amount is repeatedly encountered, and the processor can alert the user that the injector may require service. In one non-limiting example, the threshold air amount value can be 1 milliliter, although a greater or lesser amount of air may be used as the threshold amount depending on the type of injection (e.g., angiography, MRI, or computed tomography). It is also contemplated that a different threshold air amount value can be used by the fluid injector system 100 when another procedure is initiated by the fluid injector system 100. If the amount of air present in the syringe 132 and / or medical fluid is less than the threshold air amount value, the processor may allow the fluid injector system 100 to begin the fluid injection procedure because the amount of air present in the syringe 132 and / or medical fluid is at an acceptable level.

[0069] If the amount of air present in the syringe 132 and / or medical fluid is less than the threshold air amount value at step 622, the fluid injector system 100 may begin an injection procedure on the patient. If the amount of air present in the syringe 132 and / or medical fluid is greater than the threshold air amount value at step 624, the fluid injector system 100 may be prevented from initiating the fluid injection procedure because the amount of air present in the syringe 132 and / or medical fluid is too high to continue the injection procedure. In one example, the fluid injector system 100 may issue an alarm signal, such as at least one of an audible indicator, a visual indicator, or a tactile indicator, to notify a user that the fluid injection procedure is being prevented due to the presence of an unacceptable amount of air in the syringe 132 and / or medical fluid. In certain embodiments, if an unacceptable amount of air is present in the syringe 132 and / or medical fluid, the fluid injector system 100 can automatically initiate a prime or purge sequence to remove the air from the fluid injector system 100, or the fluid injector system 100 can inform the user that the fluid injection procedure cannot begin unless the user selects and initiates a prime or purge sequence. The prime or purge sequence may require a minimum prime volume (waste) required to remove the air from the system to ensure removal of the air while minimizing the amount of waste fluid generated in the prime or purge sequence. After the prime or purge sequence is completed, the processor can draw fluid from the bulk fluid container into the syringe and repeat the air detection protocol to ensure less than a threshold amount of air remains in the syringe before proceeding with the injection procedure.

[0070] Once the amount of air is calculated, certain system actions can be automatically initiated by a processor associated with the fluid injector system 100, and / or certain user actions can be limited depending on the amount of air detected by this protocol. For example, if the air amount value indicates an undesirable amount of air in the reservoir, fluid injection to the patient can be disabled until the fluid injector system 100 is primed and the air is removed from the reservoir and fluid path. Furthermore, the calculated value can be used to efficiently remove the measured amount of air from the fluid path. For example, if 2 mL of air is detected in a fluid injector system 100 whose fluid line requires 10 mL to effectively prime the fluid path, the fluid injector system 100 can adjust the prime amount to provide at least 12 mL, or slightly more, from the reservoir to ensure removal of the air using the least amount of fluid possible. The threshold used to drive subsequent system action in response to air measurement may be a static value or adjustable based on user preference, the patient's medical history or pre-existing conditions, or access to the vascular system (arterial or venous). According to some embodiments, the measured amount of air via reservoir pressurization can be used to drive subsequent injector action. For example, if the measured amount of air is greater than a certain threshold, the injector can initiate or require priming of the fluid path to remove the measured amount of air before allowing injection into the patient. Alternatively, repeated detection of the threshold amount of air can signal a fault condition that requires service and correction before further injection procedures can be performed.

[0071] After the purge sequence is initiated and completed, the air check compressibility protocol is again initiated to determine whether air is present in the syringe 132 and / or the medical fluid. If air remains within the fluid injector system 100, the purge procedure is again initiated. If the absence of air within the fluid injector system 100 is detected according to various methods herein, a fluid injection procedure to provide medical fluid to a patient can be initiated and completed.

[0072] While a direct comparison of the baseline compressibility data and the air check compressibility data correlates with the amount of air in the system, measurement error may occur due to differences between the system conditions at the time the baseline compressibility data was recorded and the system conditions at the time the air check compressibility data was recorded. For example, the volume of the reservoir in syringe 132 may have been different when the compressibility data measurements were recorded (e.g., due to a different position of the piston element between the baseline and air check determinations), which would affect the compressibility factor of the system. For example, the system's baseline compressibility data may have been recorded when 200 mL of fluid was present in syringe 132, while the system's air check compressibility data may have been recorded when only 100 mL of fluid was present in syringe 132. Because the amount of fluid in the syringe is different between the two measurements, the compliance or capacitance of the syringe will be different and must be accounted for in the calculation. 9, the position of plunger 144 in syringe 132 may be in a first position when the baseline compressibility data is acquired, but the user may not want to use syringe 132 with the same plunger 144 position when acquiring the air check compressibility data. Thus, the user may not want to fill syringe 132 to the same volume as the syringe 132 was filled to when the baseline compressibility data was recorded (e.g., the injection procedure the user is about to begin may require only a small amount of fluid, and therefore the user may not need or want to fill the syringe with a larger amount of fluid). Thus, a correction factor may be required to compensate for differences in system conditions between the recording of the baseline compressibility data and the recording of the air check compressibility data.

[0073] As discussed above, measurement errors can arise from differences in system state, system configuration, system capacitance or compliance, or manufacturing variability. Therefore, using one or more correction factors to adjust the measured amount of air based on system-specific characteristics or system elasticity variations can provide an accurate value for the amount of air in the measured fluid volume in syringe 132. In one example, a correlation between one or more correction factors, baseline compressibility data values, and / or air-check compressibility data values ​​is shown in the graph illustrated in FIG. 7. As used in FIG. 7, the term "stiffness factor" (also referred to as a correction factor) can include any variable related to any combination of system state, system configuration, system capacitance or compliance, or manufacturing variability. Such correction factors may not be necessary for systems that perform compressibility factor measurements in a relatively consistent manner. For example, in embodiments in which the same motor, reservoir, reservoir volume, etc. are used consistently between compressibility data measurements, correction factors may not be required, and measurement resolution may be improved. In certain applications, such consistency between compressibility data measurements may not be achievable. For example, an injector system may have multiple unique motors, such as two or three drive motors, and a unique set of reservoirs that may be replaced daily. Such variations in the injector system may require one or more calibration processes over time for optimal accuracy. Furthermore, various embodiments provide ease of use for operators, such as the ability to perform test measurements on any volume of fluid in the reservoir, e.g., 0-300 mL, because users are permitted to fill any volume within this range to perform an injection. To improve the ease of use of the injector system, a method of air content detection across the entire range of reservoir volumes is desirable. Because reservoir compliance is a function of the fluid volume in the reservoir, determined by, for example, piston position, establishing baseline compressibility data at one reservoir fluid volume and measuring air-check compressibility data at another reservoir fluid volume may introduce variation into the air content calculation.To correct for variations in air measurement, differences in compliance due to differences in reservoir fluid volume can be calculated and used to adjust the measured air volume. Therefore, after air check compressibility data is recorded by the system, one or more correction factors are determined and incorporated into the calculation of the air check compressibility data for comparison with the baseline compressibility data for air detection in the system. One embodiment or example (but not limited to) of an equation for the correction factor (z) is shown below: Correction Factor = A + B * (Baseline Compressibility Position (mL)) - C * (Air Check Compressibility Position (mL)), where A, B, and C are variables depending on the stiffness and compliance of the particular motor and reservoir used for various baseline and air check start volumes. In certain embodiments, A may be an offset value, B may be associated with tilt along the baseline position axis of FIG. 7, and C may be associated with tilt along the air check position axis of FIG. 7. In one non-limiting example, the value of A in the above equation ranges from -5 to 5, the value of B in the above equation ranges from -30 to 30, and the value of C in the above equation ranges from -30 to 30. In one non-limiting example, the value of A in the above equation is 0.001, the value of B in the above equation is 0.009, and the value of C in the above equation is 14.611. However, it should be understood that the values ​​of A, B, and C will vary depending on the particular fluid injector system and system components being used. The values ​​of A, B, and C may be stored in the injector's memory or otherwise available in one or more "look-up" tables that list the values ​​of the variables for particular baseline and air check volumes. While the correction factor equations are shown as linear, other embodiments may include non-linear equations depending on the fitting of associated surface plots of stiffness coefficients versus baseline and air check start volumes.

[0074] The air detection method according to various embodiments herein provides various advantages to the fluid injector system 100. In particular, air in the fluid is measured before the fluid is injected into the patient. This method minimizes the risk of injecting air into the patient because the injection procedure can be stopped before the injection begins if an amount of air exceeding a threshold is detected. In contrast, many conventional methods require a sensor, such as an air detector, to sense when air passes through the patient line to the patient, making it difficult to stop the injection procedure in time. Furthermore, the present method reduces the amount of wasted medical fluid because the presence of air can be determined and purged before injection. Another advantage is that the efficiency of the injection procedure is improved because the procedure does not need to be stopped mid-procedure and the fluid injection protocol is reset to the beginning. Furthermore, the above-described method proactively prevents the injection of air, allowing confidence that only a harmless amount of air is present in the system, reducing the need to interrupt the medical injection procedure and thereby reducing patient inconvenience and medical fluid waste. The present method also has the advantage of reducing response time delays. Conventional methods can be affected by dynamic fluid path measurements, such as when air is detected and measured after passing through a sensor. Furthermore, the measurements of the present method are independent of the impedance of the fluid path, fluid properties, or fluid dynamics (e.g., flow rate, interactions between air and fluid, etc.). The disclosed method provides stability and scalability, and air detection is independent of fluid path characteristics such as length and components.

[0075] The methods of various embodiments also allow for the calculation or determination of baseline measurements for all possible consumable / hardware combinations and configurations, correcting for mechanical slack associated with various combinations and injector components, including increased slack that can occur due to wear of mechanical components over time. This allows for optimized air detection accuracy for each consumable used. Additionally, the methods substantially eliminate inaccuracies that may be introduced during the manufacture of the injector or consumable. The methods described above are applicable to closed fluid reservoir systems, accounting for compliance issues and improving the accuracy of fluid injections. Furthermore, the methods and protocols described above are contemplated for use in open systems, taking fluid flow into account when performing baseline and air-check compressibility measurements. Various methods may be automated for automated injection procedures or protocols. Automation can minimize the potential for user error in injection protocols, resulting in improved patient safety. Furthermore, the disclosed methods may also be used to optimize the amount of air needed to prime the system. For example, by determining the amount of air trapped in the system, the system can be primed for a time and prime volume that minimizes fluid waste. Various embodiments of the method can be used with any closure system, such as CT, CV, IV, etc., that includes a valve that can be used to close the system and fluidically isolate the fluid reservoir.

[0076] Although various examples of the present disclosure have been presented in the above description, those skilled in the art can make modifications and variations to these examples without departing from the scope and spirit of the present disclosure. Accordingly, the above description is intended to be illustrative rather than limiting. The above disclosure is defined by the claims, and all modifications of the present disclosure that come within the meaning and range of equivalence of the claims are encompassed within the technical scope of the claims. [Explanation of symbols]

[0077] 100 Fluid Injector System 102 Injector housing 104 Side 106 Top 108 Bottom end 110 base 116 doors 118 Bulk Fluid Connector 120 Bulk Fluid Source 122 Support member 124 User Interface 126 control buttons 130 MUDS 132 Syringe 134 Fluid Path 136 Valve 138 Syringe body 139 Inside the syringe 140 distal end 142 proximal end 144 Syringe Plunger 145 Vertex or Cone Point 146 Discharge outlet 147 Filling port 148 Manifold 149 Pump 150 Fluid Filling Line 152 fluid outlet line 153 Air Detector 154 frames 156 Waste Reservoir

Claims

1. 1. An injector system for delivering a medical fluid, comprising: at least one syringe defining a reservoir configured to contain the medical fluid, the at least one syringe including a plunger operatively connected to a piston and at least one port in communication with the reservoir, through which the medical fluid can flow into and out of the reservoir configured to contain the medical fluid; a pump configured to move the piston and the plunger within the reservoir; at least one processor, determining a baseline value for the at least one syringe of the injector system based on an air check protocol to detect air in the reservoir, the baseline value including baseline compressibility data, wherein the reservoir is substantially filled with a first quantity of the medical fluid and a known quantity of air, the at least one syringe is pressurized, and a pressurized volume of the compressed first quantity of the medical fluid and the known quantity of air is measured to provide the baseline compressibility data based on deflections of one or more components of the injector system, compliances of the reservoir and fluid path, and the known quantity of air; delivering the first amount of the medical fluid and the known amount of air from the reservoir; refilling the reservoir with a second quantity of the medical fluid; performing an air check pressurization sequence by collecting air check compressibility data for the at least one syringe of the injector system filled with the second quantity of the medical fluid based on the air check protocol; comparing the air check compressibility data for the at least one syringe filled with a second quantity of the medical fluid to the baseline compressibility data to determine an amount of air present in the reservoir having the second quantity of the medical fluid based on the air check protocol, and incorporating a correction factor when comparing the air check compressibility data to the baseline compressibility data to account for deflections of one or more injector system components, a volume of the medical fluid that differs as compared to the volume of the first quantity of the medical fluid used to determine the baseline compressibility data, and variations in capacitance due to a position of the piston that differs as compared to a position of the piston when determining the baseline compressibility data; at least one processor programmed or configured to: An injector system comprising:

2. 2. The injector system of claim 1, wherein the processor is further programmed or configured to purge air within the first quantity of the medical fluid from the reservoir prior to determining the baseline value based on the air check protocol.

3. 3. The injector system of claim 1, wherein the processor is further programmed or configured to deliver a prime amount of the second quantity of the medical fluid from the reservoir based on the air check protocol, the prime amount of the second quantity of the medical fluid having a volume greater than a volume of air present in the reservoir.

4. 4. The injector system of claim 3, wherein the processor being further programmed or configured to deliver the prime amount of the second quantity of the medical fluid further comprises optimizing the prime amount to be equal to the minimum amount of the second quantity of the medical fluid required to remove an amount of air present in the reservoir.

5. 5. The injector system of claim 3, further comprising a downstream air detector, the downstream air detector programmed or configured to verify that no additional air is present in the fluid path after the prime amount of the second quantity of medical fluid is delivered from the reservoir.

6. 6. The injector system of claim 1, wherein the processor is further programmed or configured to determine, based on the air check protocol, whether an amount of air present in the reservoir exceeds a predetermined volume value.

7. 7. The injector system of claim 6, wherein if the amount of air present in the reservoir exceeds the predetermined volume value, the processor is further programmed or configured to purge the amount of air from the reservoir before delivering the second amount of the medical fluid from the reservoir based on the air check protocol or determine whether a fault condition exists.

8. 8. The injector system of claim 7, wherein after purging the amount of air from the reservoir, the processor is further programmed or configured to perform an additional air check pressurization sequence by collecting additional air check compressibility data from the reservoir based on the air check protocol, and comparing the additional air check compressibility data to the baseline compressibility data to determine whether any air remains in the reservoir.

9. 7. The injector system of claim 6, wherein the predetermined volume value is in the range of 0.1 milliliters to 20 milliliters.

10. 10. The injector system of claim 1, wherein comparing the air check compressibility data to the baseline compressibility data to determine the amount of air present in the reservoir comprises using a built-in algorithm to compare the air check compressibility data to the baseline compressibility data to determine the amount of air present in the reservoir.

11. 11. The injector system of claim 1, wherein the at least one syringe includes at least one valve associated with the at least one port, the at least one valve configured to move between a fill position, a delivery position, and a closed position in response to one or more instructions from the at least one processor.

12. 12. The injector system of claim 11, wherein the at least one valve is in the closed position for at least one of determining the baseline compressibility data and performing the air check pressurization sequence.

13. 1. A method for detecting air in at least one reservoir of a fluid injector system, the method comprising: determining a baseline value comprising baseline compressibility data for the at least one reservoir of the fluid injector system, the at least one reservoir having at least one fluid port and being substantially filled with a first quantity of medical fluid and a known quantity of air, wherein the at least one reservoir is pressurized and a pressurized volume of the compressed first quantity of medical fluid and the known quantity of air is measured to provide the baseline compressibility data based on deflections of one or more components of the injector system, compliances of the reservoir and fluid path, and the known quantity of air; delivering the first amount of the medical fluid and the known amount of air from the at least one reservoir; refilling the at least one reservoir with a second quantity of the medical fluid; performing an air-check pressurization sequence, including pressurizing the medical fluid in the at least one reservoir filled with a second amount of the medical fluid and collecting air-check compressibility data; comparing the air check compressibility data for the at least one reservoir filled with a second amount of the medical fluid to the baseline compressibility data to determine an amount of air present in the at least one reservoir having the second amount of the medical fluid; incorporating a correction factor when comparing the air check compressibility data to the baseline compressibility data to account for variations in capacitance due to deflection of one or more fluid injector system components, a volume of the medical fluid that differs as compared to the volume of the first quantity of the medical fluid used to determine the baseline compressibility data, and a position of the piston within the fluid injector system that differs as compared to the position of the piston when determining the baseline compressibility data; A method comprising:

14. 14. The method of claim 13, further comprising purging the known amount of air from the at least one reservoir prior to determining the baseline value.

15. 15. The method of claim 13 or 14, further comprising the step of delivering a prime amount of the second quantity of the medical fluid from the at least one reservoir, the prime amount of the second quantity of the medical fluid having a volume greater than a volume of air present in the at least one reservoir.

16. 16. The method of claim 15, wherein delivering the prime amount of the second quantity of the medical fluid further comprises optimizing the prime amount to be equal to a minimum amount of the second quantity of the medical fluid required to remove an amount of air present in the at least one reservoir.

17. 17. The method of any one of claims 13 to 16, further comprising determining whether a fault condition exists when the amount of air present in the at least one reservoir exceeds a predetermined volume value.

18. 18. The method of claim 13, further comprising the step of closing a fluid path associated with the at least one fluid inlet / outlet of the at least one reservoir prior to at least one of determining the baseline value and performing the air check pressurization sequence.

19. 19. The method of any one of claims 13 to 18, wherein the second amount of the medical fluid is different from the first amount of the medical fluid.

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