Patent ID: 12239818

DETAILED DESCRIPTION

As used herein, the singular form of “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. Spatial or directional terms, such as “left”, “right”, “inner”, “outer”, “above”, “below”, and the like, relate to the invention as shown in the drawing figures and are not to be considered as limiting, as the invention can assume various alternative orientations.

All numbers used in the specification and claims are to be understood as being modified in all instances by the term “about”. The term “about” is meant to include plus or minus twenty-five percent of the stated value, such as plus or minus ten percent of the stated value. However, this should not be considered as limiting to any analysis of the values under the doctrine of equivalents. Unless otherwise indicated, all ranges or ratios disclosed herein are to be understood to encompass the beginning and ending values and any and all subranges or sub-ratios subsumed therein. For example, a stated range or ratio of “1 to 10” should be considered to include any and all subranges or sub-ratios between (and inclusive of) the minimum value of 1 and the maximum value of 10; that is, all subranges or sub-ratios beginning with a minimum value of 1 or more and ending with a maximum value of 10 or less. The ranges and/or ratios disclosed herein represent the average values over the specified range and/or ratio. The terms “first”, “second”, and the like are not intended to refer to any particular order or chronology, but refer to different conditions, properties, or elements.

All documents referred to herein are “incorporated by reference” in their entirety.

The term “at least” is synonymous with “greater than or equal to”. The term “not greater than” is synonymous with “less than or equal to”. 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 alone; or B alone; or C alone; or A and B; or A and C; or B and C; or all of A, B, and C. The term “includes” is synonymous with “comprises”.

When used in relation to a syringe, the term “proximal” refers to a portion of a syringe nearest a piston element for engaging with an end wall of the syringe and delivering fluid from a syringe. When used in relation to a fluid path, the term “proximal” refers to a portion of the fluid path nearest to an injector system when the fluid path is connecting with the injector system. When used in relation to a syringe, the term “distal” refers to a portion of a syringe nearest to a delivery nozzle. When used in relation to a fluid path, the term “distal” refers to a portion of the fluid path nearest to a patient when the fluid path is connected with an injector system. The term “radial” refers to a direction in a cross-sectional plane normal to a longitudinal axis of a syringe extending between proximal and distal ends. The term “circumferential” refers to a direction around an inner or outer surface of a sidewall of a syringe. The term “axial” refers to a direction along a longitudinal axis of the syringe extending between the proximal and distal ends.

It is to be understood that the disclosure may assume alternative variations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary aspects of the disclosure. Hence, specific dimensions and other physical characteristics related to the examples disclosed herein are not to be considered as limiting.

Referring to the drawings in which like reference characters refer to like parts throughout the several views thereof, the present disclosure provides systems, components devices, and methods for detecting and analyzing fluid content of a fluid path section during a fluid fill operation. Referring first toFIGS.1and2, embodiments of a dual syringe fluid injector system2000are illustrated. The fluid injector system2000is configured for injection of two medical fluids from respective fluid reservoirs10A,10B, which are illustrated as syringes in the accompanying drawings. In some embodiments, the first fluid reservoir10A contains an imaging contrast media for an angiography (CV), MRI, PET, or computed tomography (CT) injection procedure, and the second fluid reservoir10B contains a flushing fluid, such as saline or Ringer's lactate. As will be understood by one of skill in the art, contrast fluids are typically an aqueous solution of a contrast agent compound at a defined concentration. Various contrast agent compounds at different concentrations are known in the art. The fluids are injected from fluid reservoirs10A,10B through a series of fluid path elements connecting the fluid reservoirs10A,10B to a catheter110inserted into the vasculature system of a patient. The fluid injector system2000may further include bulk fluid containers19A and19B for filling and refilling the respective syringes10A,10B with imaging contrast media and flushing fluid, respectively. The system2000includes a fluid path set including a first syringe line208A in fluid communication with a tip or nozzle16A of the first syringe10A, a first fill line216A in fluid communication with the first bulk fluid container19A, and a first patient line210A in fluid communication with the catheter110. In some embodiments, the first syringe line208A, the first fill line216A, and/or the first patient line210A are fluidly connected at a manifold or T-connection (see, e.g.FIGS.6and24). The fluid path set further includes a syringe line208B in fluid communication with a tip or nozzle16B of the second syringe10B, a fill line216B in fluid communication with the second bulk fluid container19B, and a patient line210B in fluid communication with the catheter110. In some embodiments, the syringe line208B, the fill line216B, and/or the patient line210B are fluidly connected at the manifold or T-connection (see, e.g.FIGS.6and24). The arrangement of the fluid path set allows fluid to be drawn from the first bulk fluid container19A into the first syringe10A via the first fill line216A and the first syringe line208A. Fluid can be injected from the first syringe10A to the patient via the first syringe line208A, the patient line210A, and the catheter110. Similarly, fluid may be drawn from the second bulk fluid container19B into the second syringe10B via the second fill line216B and the second syringe line208B. Fluid can be injected from the second syringe10B to the patient via the second syringe line208B, the second patient line210B, and the catheter110. The syringe lines208A,208B, the fill lines216A,216B, and the outlet lines210A,210B may be made of flexible tubing, although various portions thereof, for example luer connectors, sensor regions and mixing chambers may be rigid. While the fluid injector12illustrated inFIGS.1and2is shown with a first contrast syringe and a second flushing fluid syringe, in certain injection procedures, only contrast may be used, with no associated flushing fluid. According to these embodiments, the fluid injector12may be engaged with only a first syringe10A and associated first bulk reservoir19A and fluid path components for injecting the contrast into a patient. The flush side of the fluid injector12may be left empty during such a single fluid injection procedure. Alternatively, a fluid injector (not shown) configured for engagement with only a single syringe may utilize the various embodiments of sensor modules and methods described herein.

Further details and examples of suitable nonlimiting powered injector systems, including syringes, tubing and fluid path components, shut-off valves, pinch valves, controllers, and air detectors, are described in U.S. Pat. Nos. 5,383,858; 7,553,294; 7,666,169; 8,945,051; 10,022,493; and 10,507,319, and International PCT Application Nos. PCT/US2013/061275; PCT/US2018/034613; PCT/US2020/049885; PCT/US2021/035273; PCT/US2021/029963; PCT/US2021/018523; PCT/US2021/037623; PCT/US2021/037574; and PCT/US2021/045298, the disclosures of which are hereby incorporated by reference in their entireties.

With continued reference toFIGS.1and2, the injector system2000includes a first piston13A and a second piston13B respectively associated with each of the syringes10A,10B. Each of the pistons13A,13B is configured to drive a respective plunger14A,14B within a barrel of the respective syringe10A,10B. The fluid injector system2000includes a controller900in electronic communication with various components of the system2000to execute an injection procedure. In particular, the controller900may include at least one processor programmed or configured to actuate the pistons13A,13B and various other components of the injector system2000to deliver medical fluids according to a programmed protocol for an injection procedure, including, for example, monitoring at least one fluid property of one or more fluids being drawn into syringes10A,10B and determining at least one of fluid identity and fluid concentration. The controller900may then adjust at least one parameter of the injection protocol based on the at least one of fluid identity and fluid concentration, such as switching the syringe identity in the injection protocol so that the correct fluid is identified with the correct syringe10and correct injection parameters are utilized, altering a display so that the syringe image on the display correctly represents the correct fluid in the syringe, switching a color of one or more light emitters (such as an LED light) associated with the syringe to display the correct light color associated with the correct fluid type (e.g., blue for saline, green for contrast, red for air), indicate on a display the concentration of the contrast agent, adjust an injection protocol to inject a correct ratio of contrast and saline when an incorrect contrast concentration has been loaded into the contrast syringe, and provide an alert to the user that one or more errors has occurred during a fluid fill operation, such as incorrect fluid filled into the syringe, bulk fluid container is empty as only air has been drawn into the syringe, incorrect contrast concentration, changed injection protocol, and the like. The controller900may include computer readable media, such as memory, on which one or more injection protocols may be stored for execution by the at least one processor. Controller900is configured to actuate pistons13A,13B to reciprocatively move the plungers14A,14B within syringes10A,10B and thereby execute and halt an injection procedure. The fluid injector system2000may further include at least one graphical user interface (GUI)11through which an operator can interact with the controller900to view status of and control an injection procedure. In an analogous manner, if the fluid injection system2000includes one or more pumps, such as a peristaltic pump, the associated controller900may operate the various components of the fluid injector, such as the air sensor modules described herein, to ensure a correct fluid type is flowing through the correct fluid path elements based on an associated bulk fluid container, and if the fluid type is not correct, controller900may make the necessary adjustments and notifications to the injection protocol based on the actual fluid identified with the specific fluid pump.

Controller900may be programmed or configured to execute a filling operation during which the piston13A,13B associated with each syringe10A,10B is withdrawn toward a proximal end of syringe10A,10B to draw injection fluid F (e.g. imaging contrast media or flushing fluid) into syringes10A,10B from bulk fluid containers19A,19B, respectively. During such a filling operation, controller900may be programmed or configured to selectively actuate various valves, stopcocks, or clamps (such as pinch clamps) to establish fluid communication between the respective syringes10A,10B and the bulk fluid containers19A.19B via the fill lines216A and216B to control filling of the syringes10A,10B with the appropriate injection fluid F. As described herein, during the filling operation the fluid flowing through fill lines216A,216B is monitored by fluid sensors described herein to identify the one or more properties of the fluid in the fill line216A or216B and, if necessary, controller900may make the necessary adjustments to the system, injection protocol, etc., or alert a user based on the identification of the one or more properties of the fluid in fill line216A or216B.

After the filling operation and a priming operation (where excess air is removed from the syringe and various fluid path elements by flowing fluid from the syringe through the fluid path elements), the controller900may be programmed or configured to execute a fluid delivery operation during which the piston13A,13B associated with one or both of the syringes10A,10B is moved toward a distal end of the syringe to inject injection fluid F into the first patient line210A and the second patient line210B, respectively, at a specified flow rate and time to deliver a desired amount of fluid F. The controller900may be programmed or configured to selectively actuate various valves, stopcocks, and/or pinch clamps to establish fluid communication between the syringes10A,10B and the patient, via the patient lines210A.210B. The patient lines210A,210B ultimately merge before connecting to the catheter110, for example at a turbulent mixing chamber as described in PCT International Application No. PCT/US2021/019507, the disclosure of which is incorporated herein in its entirety.

According to various embodiments, the system2000includes one or more sensors and/or sensor modules configured for detecting air and/or fluid in the fluid path elements associated with each syringe10A,10B, for example, fill lines216A,216B. As shown inFIGS.1and2, a first sensor module300A is arranged to be in operative communication with the first syringe tip16A, and a second sensor module300B is arranged to be in operative communication with the second syringe tip16B. Alternatively or additionally, the first and second sensor modules300A,300B may be associated with the fill lines216A,216B. The sensor modules300A,300B are in electronic communication with the controller900so that the controller900can determine at least one property of a fluid content of a fluid path section570) (associated with fluid lines208A,208B,216A, and/or216B) based on signals transmitted by the sensor modules300A,300B. For example, based on the signals transmitted by the sensor modules300A,300B, the controller900may be configured to determine an identity of the fluid in the fluid path section570, a concentration of a medical fluid in the fluid path section570, the presence of air in the fluid path section570, a priming status of the fluid path section570, a property of the fluid path section (e.g. absorption, refractory index, tubing size, and/or manufacturing defect), and combinations of any thereof.FIGS.1and2show the sensor modules300A,300B associated with the syringe tips16A,16B. However, in other embodiments, the sensor modules300A,300B may be associated with essentially any component of the fluid path set, including the syringe lines208A,208B, the fill lines216A.216B, or the patient lines210A,210B. In some embodiments, the system2000may further include a third sensor module300C, functionally analogous to the first and second sensor modules300A,300B, downstream of a merge point of the patient lines210A,210B.

Referring toFIG.3-5, in some embodiments, each sensor module300A,300B.300C may include one or more sensors310each including an emitter312and a collector or detector314as illustrated inFIG.3. The emitter312and the detector314are spaced apart from one another defining a gap G in which is positioned the operatively associated fluid path section570). The emitter312is configured to emit electromagnetic radiation ER (e.g. light) at a predetermined wavelength toward the detector314. The electromagnetic radiation ER must pass through the fluid path section570to reach the detector314. The fluid in the fluid path section570) and, in some embodiments, the structure of the fluid path section570) itself, absorbs and/or refracts some amount of the electromagnetic radiation ER generated by the emitter312, and thus prevents that amount of electromagnetic radiation ER from reaching the detector314. In addition, the contents of the fluid path section570and, in some embodiments, the structure of the fluid path section570itself, causes the electromagnetic radiation ER to diverge or converge before reaching the detector314due to the refraction index of the fluid and the fluid path section570. Difference in measured absorption and/or refraction may be used to differentiate between an empty sensor310compared to one in which fluid path section570has been operatively inserted into the field of the sensor310, where fluid path section570only contains air. In certain embodiments, the signal from sensor310may further indicate whether the fluid path section570has been properly inserted into the sensor310. Once the fluid path section570is correctly installed within the sensor module300A,300B,300C, sensor module300A,300B,300C may then use differences in measured refraction to determine whether fluid path section570) contains a liquid fluid (contrast or aqueous flushing fluid) or air.

In some embodiments, the emitter312may be one or more light emitting diodes (LEDs) or liquid crystal configured to emit electromagnetic radiation ER at a predetermined wavelength (or range of wavelengths), although other emitter light sources are within the scope of the present disclosure. In certain embodiments, the emitter312may be able to emit electromagnetic radiation ER at more than one wavelength, depending on the fluid to be measured. For example, the emitter312may be configured to emit light at a first wavelength and emit light a second or other wavelength depending on the requirements of the fluid injection procedure. The detector314may be any detector capable of converting a quantity of received light into an electrical signal, for example a phototransistor, photoresistor, or a photodiode. In various embodiments, the detector314may be configured to measure an amount of received electromagnetic radiation ER at different specific wavelengths, depending on the wavelength emitted by the emitter312. The controller900may be configured to control the wavelength of light emitted by the emitter312and detected by the detector314. In some embodiments, the emitter312is configured to emit electromagnetic radiation on the infrared (IR) spectrum, for example between about 700 nanometers (nm) and about 2000 nm. In some embodiments, the emitter312is configured to emit electromagnetic radiation on the ultraviolet (UV) spectrum, for example between about 10 nm and about 400 nm. In particular embodiments, the electromagnetic radiation emitted by the emitter312may have a wavelength from about 700 nm to about 2000 nm, in some embodiments from about 1440 nm to about 1460 nm, and in specific embodiments of about 1450 nm. In other embodiments, the electromagnetic radiation emitted by the emitter312may have a wavelength within the IR spectrum from about 750) nm to about 950 nm, or in another embodiment from about 800 nm to about 900 nm, in some embodiments from about 880 nm to about 900 nm, and in specific embodiments about 890 nm. In other embodiments, the electromagnetic radiation emitted by the emitter312may have a wavelength within the UV spectrum from about 300 nm to about 400 nm, or in another embodiment from about 350 nm to about 400 nm, in some embodiments from about 390 nm to about 400 nm, and in specific embodiments about 395 nm. In some embodiments, the emitter312may be configured to emit acoustic, e.g. ultrasonic, energy, and the detector314may be configured to detect acoustic energy. Electromagnetic radiation in the aforementioned wavelengths (e.g. IR and UV wavelengths) may have an advantage over other imaging protocols, such as ultrasound, in that electromagnetic radiation does not require acoustic coupling (e.g. compressive contact) between the fluid path section570) and sensor310.

The specific wavelength of electromagnetic radiation may be selected based on the fluids F used in the injection procedure and the structural properties of the fluid path section570). Particularly, the wavelength(s) of electromagnetic radiation may be chosen that provide maximum differentiation in the output signal of the detector314for various fluids of concern. For example, the emitter312may be selected and/or configured to emit electromagnetic radiation of a wavelength that exhibits the greatest difference in transmission through saline and contrast media. In some embodiments, the emitter312may be configured to emit electromagnetic radiation at multiple wavelengths (either concurrently or in alternating pulses) to improve sensitivity of the sensor310. For example, the emitter312may be configured to emit electromagnetic radiation at a first wavelength optimized for differentiating between saline and contrast media, and to emit electromagnetic radiation at a second wavelength optimized for differentiating between concentrations of contrast media.

In some embodiments, the wavelength(s) of electromagnetic radiation may be chosen to minimize adverse effects of factors on sensor performance, such as alignment of the electromagnetic radiation emitter312and detector314, alignment of fluid path set570) with the emitter312and detector314: the material and geometry of the outer sidewall of fluid path section570; and exposure of detector314to ambient light. The span of the gap G between the emitter312and detector314may also be selected to maximize differentiation in the output signal of detector314for various fluids. For example, empirical testing on a standard tube having a nominal outer diameter of 0.188 inches found that a gap G of 0.228 inches was preferable to gaps G of 0.188 inches and 0.208 inches in terms of the ability of detector314to differentiate between air, contrast, and saline in the tubing. (seeFIGS.8A and8B)

FIG.3illustrates the absence of a fluid path section in the gap G, so the electromagnetic radiation ER must pass through only the air in the gap G to reach the detector314.FIG.4illustrates the fluid path section570placed in the gap G in operative association with the sensor310. The fluid path section570inFIG.4is filled with the injection fluid F as would be expected during a filling operation of an injection procedure where fluid is moved from the bulk fluid container19A,19B to the syringe10A,10B. The refractive index of the injection fluid F may cause the electromagnetic radiation ER passing through the fluid path section570to converge before reaching the detector314, thereby causing an increase in signal intensity received and measured by the detector314. Additionally, the injection fluid F (for example solute molecules dissolved in an aqueous solution, typical of saline flushing fluid or an imaging contrast) absorbs some of the electromagnetic radiation ER generated by the emitter312, preventing some of the electromagnetic radiation ER from reaching the detector314.FIG.5illustrates the fluid path section570placed in the gap G in operative association with the sensor310, where the fluid path section570is filled with air as would be expected prior to priming the fluid path section570or initiating a filling operation of the syringe10A,10B, or which may occur if an air bubble is present in the injection fluid F during an injection procedure. The refractive index of the air causes the electromagnetic radiation ER passing through the fluid path section570to diverge before reaching the detector314, thereby causing a decrease in signal intensity receive and measured by the detector314.

Further, the absorption associated with the air-filled fluid path section570would absorb less light than a liquid filled fluid path section570(FIG.4) but would absorb more light than in a situation where the fluid path section570is not in gap G (FIG.3) due to the absorption of light by the polymeric material of the fluid path section sidewalls. In specific embodiments, light absorption by the content between the emitter312and detector314may cause a difference in signal intensity measured by the detector314. For example, inFIG.3, where no fluid path section570is present, the light may pass freely from the emitter312to the detector314of the sensor310with only a minimum decrease in signal intensity, since air has only a minimal absorption of light from the emitter312(which can be factored into any calculation). When a fluid filled fluid path section570is inserted into sensor310, the signal of light passing from the emitter312to detector314is attenuated by absorption by the molecular makeup of the sidewalls of as well as the fluid within the fluid path section570. In conditions where fluid path section570is filled with air, the signal of light passing from the emitter312to detector314is attenuated by absorption by the molecular makeup of the sidewalls of fluid path570) (no absorption by the unprimed air in the fluid path or in a large air bubble). According to various embodiments, detector312may be able to use a difference in light attenuation resulting from different liquids within the fluid path to differentiate between different contrast types or concentrations; or between contrast and saline, within fluid path section570).

The detector314is configured to transmit an output signal (e.g. an output voltage) to the controller900based on signal strength from the detected electromagnetic radiation ER. Thus, the output signal will be different depending on refractive index and absorption properties of the contents in the gap G, allowing the controller900to determine whether the fluid path section570is absent (FIG.3), the fluid path section570is present and filled with medical fluid F (FIG.4), or the fluid path section570is present and filled at least partially with air (FIG.5). In various embodiments, the controller900may determine a type of fluid (e.g. from a known database of commercially available contrast media solution) and/or a dilution ratio of fluid (i.e. a ratio of contrast media to saline during a dual-flow injection) based on the output signal of the detector314. In particular, the sensor module300C (FIG.2) downstream of the merge point of the patient lines210A,210B may be configured to measure dilution of the contrast from the first syringe10A by saline from the second syringe10B. To produce reliable results, the emitter312, detector314, and fluid path section570are selected and arranged so that the output signal generated by the detector314is sufficiently different between fluid types that the sensor310is able to distinguish between the different contrast agent types and/or the different dilution ratios. For example, if the sensor310is intended to distinguish between contrast media and saline, the emitter312, detector314, and fluid path section570) are selected and arranged such that a range of output voltages of the detector314when saline is present in the fluid path section570does not overlap with a range of output voltages of the detector314when contrast media is present in the fluid path section570. Similarly, if the sensor310is intended to distinguish between contrast media types, the emitter312, detector314, and fluid path section570are selected and arranged such that a range of output voltages of the detector314when a particular contrast type is present in the fluid path section570) does not overlap with a range of output voltages of the detector314when a different contrast media type is present in the fluid path section570.

FIG.23illustrates an electrical schematic of the sensor310in accordance with an embodiment of the present disclosure. As noted herein, the sensor310includes the emitter312and the detector314arranged such that the detector314receives electromagnetic radiation from the emitter312, with the received electromagnetic radiation being altered by the absorption and/or refraction of the fluid path section570and its contents. The emitter312and detector314are powered by respective power supplies320,321. The power supplies320,321may be 5 volt power supplies, which may be standalone devices or outputs of the controller900. The power supply320associated with the emitter312allows the controller900to calibrate the emitter312by adjusting supplied current. The power supply321supplies a fixed reference voltage to the detector314relating to the stability of the resulting output voltage of the sensor310. The emitter312may include one or more LEDs emitting one or more specific wavelengths of electromagnetic radiation, with a current-limiting resistor322placed in series to maintain an appropriate forward current through the LED(s). The detector314may be one or more phototransistors, photoresistors, or photodiodes with an associated sensor resistor324. The sensor resistor324converts a current generated by the detector314in response to detecting electromagnetic radiation into an output voltage signal326to pass to the controller900.

Referring toFIG.6, in some embodiments, sensor modules300A,300B may be provided in a manifold housing module220associated with fluid injector12. The manifold housing module220may define a receiving channel222for removably receiving a manifold500of the fluid path set. The manifold500may be a disposable component serving as a junction for the first syringe line208A, first patient line210A, and first fill line216A (FIG.2). In particular, manifold500may include a first inlet port510connected to or integrally formed with syringe line208A, a first outlet port512connected to or integrally formed with patient line210A, and a first fill port514is connected to or integrally formed with fill line216A. Similarly, manifold500may serve as a junction for the second syringe line208B, second patient line210B, and second fill line216B (FIG.2). The manifold500may include a second inlet port520connected to or integrally formed with syringe line208B, a second outlet port522connected to or integrally formed with patient line210B, and a second fill port524connected to or integrally formed with fill line216B. The manifold500defines respective fluid path sections570adjacent to each of fill ports514,524that are configured to be operatively positioned between the emitter312and detector314of respective sensor modules300A,300B.

The manifold500may include at least one connecting beam550that, along with the receiving channel222, orients and positions the manifold500and correctly indexes and interfaces the fluid path sections570with the sensor modules300A,300B. Thus, the manifold500is designed to allow a user to quickly and accurately install the tubing set into the manifold housing module220, such that the air detection regions of the fluid flow paths are correctly inserted into the reading portions of the sensor modules300A,300B. For example, in preparing the fluid injector system2000for a new injection procedure, the user may simply connect the syringe lines208A,208B to the syringes10A,10B, snap the manifold500into the manifold housing module220, and connect the fill lines216A,216B to the bulk fluid sources19A,19B (for example by spiking the fill lines216A,216B into the respective bulk fluid source19A.19B) and the fluid path set should be ready for priming. In certain cases, the manifold500and the manifold housing module220may include complementary latching components, for example on the at least one connecting beam550, to releasably engage the manifold500with the manifold housing module220. In certain embodiments, the manifold500and associated fluid path components may be a disposable component configured for use during a single injection procedure or for a series of injection procedures on a single patient. In other embodiments, the manifold500and associated fluid path components may be a disposable component of a multi-use portion of the fluid path set, which can be used in conjunction with multiple single-use portions, over several fluid injection procedures before being disposed of, for example after a set number of injections or 24 hours of use.

The fluid path sections570each include a sidewall530configured to allow passage of electromagnetic radiation from the emitters312to the detectors314when the fluid path sections570) are disposed in operative association with the sensor modules300A,300B. Each sidewall530is at least partially transparent to the predetermined wavelengths of electromagnetic radiation ER generated by the emitters312. The sidewalls530may be made of an at least partially transparent material, such as a polymer, glass, transparent composite, crystal, or other suitable material. In certain embodiments, the sidewall530may be constructed of a plastic material such as polyethylene terephthalate (PET), polycarbonate (PC), or polypropylene (PP) having a predetermined index of refraction. In some embodiments, the index of refraction of the sidewall530is closer to an index of refraction of water than to an index of refraction of air. In some embodiments, the sidewall530may be rigid so that the sidewall530cannot deflect, which could alter the path of electromagnetic radiation ER through the fluid path section570) and cause unreliable sensor readings. In certain embodiments, the sidewall530may be curved extending circumferentially around the outer surface of the fluid path section570. In other embodiments, the sidewall530may have one or more substantially planar exterior surfaces and interior surfaces. The one or more substantially planar surfaces may be located so that the path of electromagnetic radiation from the emitter312to the detector314passes through the one or more substantially planar surfaces. According to these embodiments, the one or more substantially planar surfaces may minimize or eliminate any focusing or defocusing lensing effect by the surface on the beam of electromagnetic radiation as it passes through the first fluid path section570. In other embodiments, sidewall530may include or act as a lens to concentrate or disperse the electromagnetic radiation passing through the fluid path section570). For example, sidewall530may have one or more flat surfaces, which may more predictably transmit light than curved surfaces, and in some embodiments, sidewall530) may be a square tube. In some embodiments, sidewall530may have a surface finish to concentrate or disperse electromagnetic radiation passing through fluid path section570.

With reference toFIG.6, manifold500may include one or more check valves, such as check valves516,526respectively located in the fill ports514,524. Check valves516,526may act to prevent backflow of fluid into the bulk fluid containers19A,19B during a pressurized injection. In some embodiments, additional check valves or actively-controlled valves (e.g. stopcocks, pinch valves, etc.) may be located in any of inlet ports510,520, outlet ports512,522, and fill ports514,524to selectively control fluid flow through manifold500.

The manifold500may include one or more encoded identifiers580, such as a barcode, QR-code, RFID tag or the like, for example located on the at least one connecting beam550) or fluid path wall. The fluid injector12may have an appropriately positioned reader280, such as a barcode reader, QR-code reader, RFID reader, associated with the manifold housing module220. Upon correct engagement of the manifold500with the manifold housing module220, the encoded identifier580is read by the reader to determine one or more property of the manifold500and associated fluid path elements, such as at least one of: that the manifold500is correctly inserted, that the correct manifold500for the injection procedure, that the manufacture date of the manifold500and associated fluid path components is within the required time frame, and to determine whether the manufacturer of the manifold500is an approved manufacturer. If the controller900determines that the encoded identifier indicated that there may be an issue with the manifold500, the controller900may alert the user and require correction of the issue before the fluid injection procedure may be performed.

With continued reference toFIG.6, the manifold housing module220may include additional sensor modules300X,300Y associated with the fluid path sections adjacent the respective inlet port510,520. The additional sensor modules300X,300Y may generally be similar in structure to the sensor modules300A,300B. However, various attributes of the additional sensor modules300X,300Y may differ from the sensor modules300A,300B in order to facilitate different functions. For example, the additional sensor modules300X,300Y may be particularly configured for air bubble detection and analysis, as described in PCT International Application PCT/US2022/017812, filed 25 Feb. 2022, the disclosures of each of which are incorporated herein by this reference. Further details of the structure and function of the manifold500and the manifold housing module220are shown in PCT International Application PCT/US2022/017812.

Referring toFIG.7, one embodiment of sensor modules300A,300B is illustrated in operative association with a corresponding syringe tip16A,16B so as to detect fluid in the fluid path section570entering the corresponding syringe10A,10B during a filling operation. The syringe tips16A,16B themselves may serve as fluid path sections aligned with the sensor310, or a separate fluid path section570may be attached to the syringe tips16A,16B and aligned with the sensor310. The fluid path section570includes a sidewall530, which may be similar to the sidewall described in connection withFIG.6, that is at least partially transparent to the wavelength of electromagnetic radiation generated by the emitter312. The sidewall530may be constructed of a plastic material such as polyethylene terephthalate (PET), polycarbonate (PC), or polypropylene (PP) having a predetermined index of refraction. In some embodiments, the index of refraction of the sidewall530is closer to an index of refraction of water than to an index of refraction of air. In some embodiments, the sidewall530may be rigid so that the sidewall530cannot deflect, which could alter the path of electromagnetic radiation ER through the fluid path section570) and cause unreliable sensor readings. In some embodiments, the sidewall530may include or act as a lens to refract and concentrate or disperse the electromagnetic radiation passing through the fluid path section570. In some embodiments, the sidewall530may have a surface finish to concentrate or disperse the electromagnetic radiation passing through the fluid path section570. The sensor modules300A,300B may be free to rotate about the syringe tips16A,16B to allow the operator freedom in positioning the sensor modules300A,300B, e.g., to avoid particular orientations that would receive large amounts of ambient light. Optic filters318may be provided between the emitter312and detector314to prevent ambient light from affecting a measurement of detector314.

The emitter312and the detector314may be arranged in a wide diameter section Dw of the fluid path section570. This arrangement forces the electromagnetic radiation emitted by the emitter312to travel through a relatively large diameter of fluid, allowing for more absorption and/or refraction of the electromagnetic radiation by the fluid. Empirical testing has shown that the greater absorption allowed by larger diameter of fluid increases the differentiation in detector output signal between fluid types. Thus, an increase in the diameter of the fluid path section570through which the electromagnetic radiation travels can lead to more reliable and improved determinations of the fluid properties within the fluid path section570) by the controller900. In some empirically tested embodiments, increasing diameter of the fluid path section570) accentuates the difference in absorption in a squared relationship: i.e., a small increase in diameter of the fluid path section has a relatively larger impact on a fluid's absorption of electromagnetic radiation.

The sensor modules300A,300B may include a collimating aperture350associated with the emitter312and/or a collimating aperture352associated the detector314. The collimating aperture350) associated with the emitter312may restrict the electromagnetic radiation leaving the emitter312to a substantially straight trajectory toward the detector314. The collimating aperture352associated with the detector314may limit the peripheral field of view of the detector314such that only electromagnetic radiation coming from the direction of the emitter312can reach the detectors314. Thus, the collimating aperture352may shield the detector314from ambient light sources. In some embodiments, the collimating apertures350,352may have a lesser length than diameter. In some embodiments, the collimating apertures350,352may have a greater length than diameter.

The sensor modules300A,300B may include one or more additional sensors410,410′ configured to provide further analysis of the fluid path section570. The additional sensors410,410′ may generally be similar in structure to the sensor310, so any features of the sensor310described herein may equally apply to the additional sensors410,410′. However, various attributes of the additional sensors410,410′ may differ from the sensor310in order to facilitate different functions. For example, the additional sensors410,410′ may be particularly configured for air bubble detection and analysis. Examples of additional sensors for determination of air bubble detection and analysis are presented in PCT International Application PCT/US2022/017812. Respective emitters412,412′ of the additional sensors410,410′ may be configured to emit electromagnetic radiation at the same or a different wavelength than the sensor310. In the embodiment shown inFIG.7, the additional sensors410,410′ are located downstream of the sensor310. In other embodiments, the additional sensors410,410′ may be located upstream of the sensor310, or at an entirely different location in the fluid path set. The sensor310and the additional sensors410,410′ may be configured to differentiate between air and fluid (e.g., saline and contrast media) in the fluid path section570. In some embodiments, the additional sensors410,410′ may be configured to work in tandem with the controller900to detect air bubbles in the fluid path section570, to determine the flow rate of detected air bubbles, and/or to determine the volume of detected air bubbles. Controller900may be configured to determine a flow rate of such detected air bubbles based on a time offset between the air bubbles being detected by the proximal detector414and distal detector414′.

Referring toFIG.24, in another embodiment, a manifold600including a fluid path section670may be attached to each syringe tip16A,16B, and the sensor modules300A,300B may be placed in operative association with the fluid path section670of the manifold600. The manifold600and associated sidewall630may clip to or otherwise engage with corresponding features of on the tip16A,16B of syringes10A,10B by a clipping engagement mechanism as described in PCT International Application No. PCT/US2021/018523, the disclosure of which is incorporated by this reference. The manifold600includes an inlet port610configured for connection to the syringe tip16A,16B with or without (as shown) intervening flexible tubing (i.e. the corresponding syringe line208A,208B). The manifold600further includes an outlet port612configured for connection to the corresponding patient line210A,210B, and a fill port614configured for connection to the corresponding fill line216A,216B. The fluid path section670includes a sidewall630, which may be substantially similar to the sidewall530shown and described in connection withFIGS.6and7.

Referring toFIGS.1,2,6,7, and24, in certain embodiments, the sensor modules300A,300B may be utilized for gross air detection within the fill lines216A,216B during an angiography (CV) or computed tomography (CT) procedure that accommodates refill of the syringes10A,10B during use from a bulk fluid containers19A,19B. As noted herein, the sensor modules300A,300B may be used to distinguish between injection fluid F and air in the fluid path section570, to distinguish between two types of injection fluid common to the MR. CV or CT injection procedures (i.e., contrast types and saline), to distinguish between type and/or concentration of contrast media, to determine if the fluid path section570has been inserted into the sensor module300A,300B, and to determine the presence or absence of the fluid path section570itself. In particular, the controller900may be configured to automatically identify the fluid content of each syringe10A,10B based on the output signal of the detector314. The controller900may display the contents of the syringes10A,10B to the operator, for example via a message or graphic on the GUI11or by a color associated with the fluid type (e.g., green or purple for contrast and blue for saline or other flushing solution). For example, the GUI11may graphically depict the syringes10A,10B, showing each in a predetermined color depending on the contents of the syringes10A,10B. Presuming the syringes10A,10B are filled as expected, with the first syringe10A containing contrast media and the second syringe10B containing saline, the GUI11could illustrate the first syringe10A in green or purple and the second syringe10B in blue. It is understood that other colors may be used to represent certain fluid types and represent when air is detected the sensor modules300A,300B.

In some embodiments, the controller900may illuminate the syringes10A,10B or other portions of the system2000to indicate the contents of the syringes10A,10B as determined by the sensor modules300A,300B and the controller900. For example, the controller900may illuminate a light source optically connected to each syringe10A,10B, with the syringes10A,10B acting as light tubes to display a color indicative of the fill contents of the syringes10A,10B (e.g. green for contrast media and blue for saline). The plungers14A,14B may be backlit as described in U.S. Application Publication No. 2017/0056603, the disclosure of which is hereby incorporated by reference in its entirety, to indicate the contents of the syringes10A,10B as determined by sensor modules300A,300B.

In some embodiments, the controller900may be configured to communicate a warning to the operator, for example on the GUI11or in the form of a warning alert (e.g., audible or visual), if there is an error in the fluid arrangement vis-à-vis the requirements of a prescribed injection protocol. In some embodiments, the controller900may utilize a visual indication, for example a light display to indicate the absence of the fluid path section570in operative position in the sensor modules300A,300B (e.g., yellow warning light), the presence of air in the fluid path section570(e.g., red stop injection light), the presence of saline in the fluid path section570) (blue light), or the presence of contrast media in the fluid path section570) (e.g., green light). In certain embodiments, if air is detected in the fluid path section570, the controller900may be configured to disable the injection procedure until a purging operation is performed and no further air is detected in the tubing, either automatically by the controller900or under direction of the operator.

In some embodiments, the controller900may be configured to perform safety checks and/or adjust parameters of an injection procedure if a fault is detected prior to or during an injection. For example, the controller900, via the sensor module300A associated with the first syringe10A, may monitor the fluid path section570during a filling operation in which contrast media is drawn from the bulk fluid container19A into the syringe10A. The controller900may monitor the output signal of the detector314of the sensor module300A to determine whether first syringe10A is indeed receiving contrast media or is instead being filled with saline—for example because the operator incorrectly connected the bulk fluid containers19A,19B to the wrong syringes10A,10B. Similarly, the controller900may monitor the output signal of the detector314of the sensor module300B to determine whether the second syringe10B intended to be filled with saline is instead being filled with contrast media. If either or both conditions are true, the controller900can alert the operator, via a message displayed on the GUI11, and/or automatically stop the fill procedure. In some embodiments, the controller900is configured to continue with the fill procedure and adjust the injection protocol and GUI display so that the first syringe10A is shown as the saline syringe (i.e., by highlighting the syringe blue on the GUI) and the controller injects the saline from syringe10A using parameters that were programmed for saline and originally intended to be injected by the second syringe10B. In a similar manner, the controller900may adjust the injection protocol and GUI display so that the second syringe10A is shown as the contrast syringe (i.e., by highlighting the syringe green on the GUI) and the controller injects the contrast from syringe10B using parameters that were programmed for the contrast injection and originally intended to be injected by the first syringe10A. In such embodiments, the controller900may be configured to update the display of the GUI to indicate this reversal of which syringe delivers which medical fluid. The capability of proceeding with an injection procedure even if the syringes10A,10B are filled incorrectly can reduce waste as the improperly loaded injection fluids need not be discarded and the filling operation need not be repeated.

In some embodiments, the controller900may be configured to adjust an injection ratio of contrast media to saline if the sensor module300A detects that the concentration of the contrast media in the first syringe10A is different than the concentration required by the injection protocol. If the controller900determines, based on the output signal of the sensor module300A, that the contrast media in the syringe10A is more concentrated than prescribed in the injection protocol, the controller900can alert the operator and/or automatically increase the ratio of saline injected during the procedure to dilute the concentration of the contrast media delivered to the patient. Similarly, in a dual flow procedure the controller900can reduce the injection rate of saline during the injection procedure to increase the concentration of the contrast media, for example if the contrast media in the first syringe10A is less concentrated than prescribed in the injection protocol.

According to various embodiments, when no fluid path section is present in one or both of the sensor modules300A,300B, the resulting output signal from the corresponding detector314may be used by the controller900as a calibration point against which the controller900can assess subsequent output signals from the detector314. When the fluid path section570) contains air or an air bubble, a lower level of light transmission occurs through the fluid path section, for example due to absorption or scattering of light by the sidewall530, such that less light reaches the detector314, resulting in a lower detector output voltage. Alternatively, when a fluid is present in the fluid path section570, the fluid light adsorption properties and/or index of refraction causes the light to be absorbed and/or refract as it travels through the fluid path section570, resulting in an even lower level of light reaching the detector314compared to air in the fluid path section570. The type of fluid affects the light transmission properties. For example, saline absorbs/refracts a first amount of light to the detector314greater than the amount of light absorbed/refracted by an air filled fluid path section570, due to the solute (salts) dissolved in the aqueous solution, resulting in a first voltage readout lower than for air or for the absence of the fluid path section570. Contrast media absorbs/refracts a second amount of light to the detector134greater than the amount of light absorbed/refracted by a saline or air filled fluid path section570or no fluid path, due to the type of solute (contrast molecules) dissolved in the aqueous solution, resulting in a lower voltage readout. While the foregoing description associates increased light transmission with higher voltage outputs of detector314and greater light absorption with a lower voltage output, this relationship is a function of the actual circuitry driving sensor310, such that some embodiments may exhibit a reduction in voltage output of the detector at higher light transmittance.

As described herein, according to certain embodiments the sensitivity of the detector314may also allow differentiation of different types of contrast and/or different concentrations of the same contrast media. For example, different concentrations of the same contrast media will have different densities due to different amounts of solute dissolved in the solution, resulting in different indexes of refraction and/or different amounts of light absorption. As such, the fluids will allow different levels of electromagnetic radiation to reach the detector314, resulting in different detector output voltage signals. In some embodiments, the controller900may be calibrated or may be configured to reference a database associated with output voltages of different contrast types or different contrast concentrations, for example in a look-up database programmed into the controller900. The controller900may thus be able to determine which brand, type, and/or concentration of contrast media is in the first syringe10A (or in the second syringe10B in the event that the second syringe10B is inadvertently filled with contrast media) and update the GUI as necessary or alert the user that an incorrect contrast or an incorrect contrast concentration has been loaded into syringe10A.

In some embodiments, the controller900may determine the type of fluid in the fluid path section in order to optimize fill time of the syringes10A,10B. By identifying the type of fluid in the fill fluid line216A,216B, the controller900may set a predetermined safe filling rate for the syringes10A,10B, i.e. a flow rate into the syringes10A,10B that minimizes the syringe fill time while reducing the occurrence of bubble generated in the fluid by excess flow rate of the fluid into the syringe. For example, the controller900may store and utilize the results of air detection and correlate them to specific fill speeds so that an optimal fill rate (fastest speed) may be determined that prevents or reduces introduction of air bubbles into the fluid in the syringes10A,10B. For example, a predetermined safe filling rate for saline may be higher than a predetermined safe filling rate of contrast media.

Referring toFIG.8A, a histogram2100shows empirically observed output voltages of the detector314for various fluids in the fluid path section570operatively associated with the sensor310. The wavelength of light according utilized inFIGS.8A and8Bwas 890 nm. The voltages were measured in 0.188 inch outer diameter tubing with infrared light generated by the emitter312, and with a sensor gap G of 0.228 inches. The gap G of 0.228 inches was found to be the optimal size for obtaining signal differentiation in 0.188 inch tube. As may be appreciated fromFIG.8A, the observed output voltages of the detector314for an empty tube (i.e. only air in the fluid path section570) fell within a range of 0) volts to 0.25 volts. The observed output voltages of the detector314for no tube (i.e. the fluid path section570) not positioned in operative association with the sensor310) fell within a range of 1 volt to 1.25 volts. The observed output voltages of the detector314for saline in the fluid path section fell in a range of 3.75 volts to 4.25 volts. And the observed output voltages of the detector314for contrast in the fluid path section570) fell in a range of 4.75 volts to 5 volts. The clustering of voltage outputs exhibited by the various fluids (or lack thereof) in the fluid path section570illustrate that the sensor310may reliably differentiate between these fluid types based on the output voltage of the detector314.

Referring toFIG.8B, a graph2150shows the standard deviation of detector output voltages over several test measurements of various fluids in the fluid path section570, again using infrared light and a gap G of 0.228 inches as shown inFIG.8A. The fluids for which data is shown include saline (for which three sets of data were analyzed) and the following commercially available contrast media solutions: Ultravist® 370, Ultravist® 300, Omnipaque™ 240, Omnipaque™ 350, Isovue® 370, Isovue® 300, and Isovue® 250. For all fluids except Isovue® 370 and one instance of saline, the standard deviation in the detector output voltages was less than 0.01 volts. The low standards of deviation for these fluids indicate that the output voltage of the detector314is consistent for each particular fluid, again indicating that the sensor310can reliably differentiate between contrast media solutions based on the detector output voltage. Based on this or similar empirical data, the controller900may be programmed with predetermined thresholds, such as upper bounds and lower bounds, associated with air, saline, and various types of contrast media. During an injection procedure, if the output signal from the detector314falls within the predetermined upper and lower bounds associated with air, the controller900determines that air is present in the fluid path section570. Likewise, if the output signal from the detector falls within the predetermined upper and lower bounds associated with contrast media, the controller900determines that contrast media is present in the fluid path section570. In some embodiments, only an upper bound or only a lower bound may be used as one of the predetermined thresholds. For example, the controller900may not have an upper bound associated with air, as the output voltage signal of saline or contrast media would never be less than that of air. In some embodiments, the controller900may interpret an output signal significantly outside an expected range of values as a fault condition and may alert the operator (for example via a message displayed on the GUI11) and/or automatically halt the injection procedure. For example, if the output signal is above 5 volts in this embodiment, which as evident from graph2100is greater than the expected output voltage associated with any fluid in the fluid path section570, the controller900may determine that a fault has occurred.

Referring toFIG.9, graph2200shows empirically observed detector output signal voltages for water, contrast media, and a 50:50 solution of water and contrast media, again for the emitter312operating at 1450 nm. In this embodiment, the average detector output voltage for water in the fluid path section570is between 150 millivolt (mV) and 200 mV, the average detector output voltage for a 50:50 solution of contrast and water in the fluid path section570) is between 200 mV and 250 mV, and the average detector output voltage for contrast media in the fluid path section570) is between 250 mV and 300 mV.

Referring toFIG.10, graph2300shows empirically observed detector output signal voltages for water, contrast media, and a 50:50 solution of water and contrast media, in an embodiment in which the emitter312generates electromagnetic radiation on the ultraviolet spectrum at 395 nm. In this embodiment, the average detector output voltage for water in the fluid path section570is between 1600 mV and 1800 mV, the average detector output voltage for a 50:50 solution of contrast media and water in the fluid path section570is between 1400 mV and 1600 mV, and the average detector output voltage for contrast media in the fluid path section570is approximately 1200 mV.

Referring toFIG.11, graph2400shows empirically observed detector output signal voltages for various dilution ratios of contrast media to water, again in an embodiment in which the emitter312generates electromagnetic radiation on the UV spectrum at about 395 nm. In this embodiment, the average detector output voltage for 100% contrast media in the fluid path section570is approximately 1200 mV, and the average detector output voltage gradually increases at 75% contrast. 50% contrast, 25% contrast, and 0% contrast (100% water). Thus, in this embodiment, the percentage of contrast media in the solution has an inverse effect on the output voltage of the detector314.

FIGS.8A-11merely show data for a small number of embodiments, with specific configurations of the sensor310. Other configurations, which may use a different type of emitter312or detector314, different circuitry associated with the emitter312or detector314, different gap spacing between the emitter312and the detector314, different tubing diameters, different strengths of electromagnetic radiation, and/or different optical lenses or filters may produce different output voltages when detecting the same fluids as illustrated inFIGS.8A-11. In some embodiments, for example, the detector314may output a voltage of approximately 1.609 volts if the fluid path section is not present, approximately 0.609 volts if the fluid path section is filled with air, approximately 3.43 volts if the fluid path section is filled with saline, and approximately 4.65 volts if the fluid path section is filled with contrast media. In other embodiments, the detector314may output a voltage of approximately 5.0 volts if the fluid path section is not present, approximately 2.5 volts if the fluid path section is filled with air, and approximately 1.0 volts if the fluid path section is filled with contrast media. Detector output voltages may be manipulated to a certain extent through calibration (e.g. changing the resistor322,324in the sensor circuit ofFIG.23) to produce output voltages with greater sensitivity.

Referring toFIGS.12-15, graphs2500-2800illustrate various empirically observed transmission percentages for electromagnetic radiation through various commercially available contrast media solutions as a function of wavelength generated by the emitter312. Referring first toFIG.12, graph2500shows experimental data gathered for relative transmission of electromagnetic radiation through various dilutions of Ultravist® 370 contrast media in a 10 millimeter (mm) glass cuvette. Transmission of electromagnetic radiation through water in a 10 mm glass cuvette is also shown as a baseline value, with essentially 100% transmission rate. The graphed dilutions include pure Ultravist® 370 and ratios of 1:1, 2:1, and 3:1 water to Ultravist® 370. As can be appreciated from graph2500, the greatest differentiation in relative transmission between the various dilutions occurs in or near the UV spectrum, for example at a region from 370 to 390 nm, and in particular approximately 379 nm in this embodiment.

The difference in relative transmission at a given wavelength can be used to differentiate between saline (similar to water) and contrast, and between the various dilutions of contrast with water. In particular, the detector314detects the electromagnetic radiation transmitted through the fluid in the fluid path section570, so differences in transmission percentages of the various dilutions result in different amounts of electromagnetic radiation reaching the detector314. Consequently, the resulting output signal generated by the detector314will be different for water and contrast dilutions having different transmission percentages at a given wavelength. By using an emitter312emitting electromagnetic radiation at a predetermined wavelength, for example at approximately 379 nm, the controller900may be able to determine approximately which dilution ratio of Ultravist® 370 is present in the fluid path section570) based on the output signal of the detector314. In particular, the controller900may be configured to match the output voltage of the detector314to known output voltages associated with various dilutions of Ultravist® 370. In some embodiments, the controller900may be configured to reference a database of known output voltages associated with various dilutions. In some embodiments, the controller900may be configured to interpolate a dilution ratio of Ultravist® 370 based on the output voltage of the detector314.

Referring toFIG.13, graph2600shows transmission percentage of electromagnetic radiation with wavelengths falling between 350 and 450 nm through various commercially available contrast media solutions including Isovue® 128. Isovue® 250, Isovue® 370. Omnipaque™ 300, and Ultravist® 370. Graph2700ofFIG.14shows the same data as graph2600but expanded for electromagnetic radiation with wavelengths falling between about 200 and about 1020 nm. Graph2800ofFIG.15shows transmission percentage of the same commercially available contrast media solutions for electromagnetic radiation with wavelengths falling between 900 nm and 1050 nm. As noted inFIG.12, the difference in relative transmission at a given wavelength may be used to differentiate between the various contrast media solutions. As can be appreciated fromFIGS.13-15, the greatest differentiation in transmission percentage of the various contrast media solution may occur in or near the infrared and ultraviolet regions of the electromagnetic spectrums. Thus, the emitter312may be configured to generate electromagnetic radiation in or near the infrared and ultraviolet spectrums to take advantage of this differentiation. In other embodiments, the emitter312may be configured to generate electromagnetic radiation in the visible spectrum. In other embodiments, the emitter312may be able to generate electromagnetic radiation at two or more different wavelengths, such as two wavelengths within the infrared region of the electromagnetic spectrum, two wavelengths within the ultraviolet region of the electromagnetic spectrum, or at a wavelength in the infrared region and a wavelength in the ultraviolet region of the electromagnetic spectrum. Accordingly, the emitter312may pulse electromagnetic radiation at different wavelengths through the fluid path section570to gather several absorption/transmission data points on the fluid in the fluid path section570to more accurately determine the identity of the fluid within the fluid path section570. In some embodiments, the controller900may be configured to determine which of the contrast media solutions is present in the fluid path section570based on the output signal of the detector314. In particular, the controller900may be configured to match the output voltage of the detector314to known output voltages associated with various commercially available contrast media solutions. In some embodiments, the controller900may be configured to reference a database of known output voltages associated with various commercially available contrast media solutions.

Referring toFIGS.16-20, various tubing geometries and manufacturing defects which may be present in the fluid path section associated with the sensor310are shown.FIG.16shows an eccentricity in which a lumen580of the fluid path section is not concentric with the sidewall530.FIG.17shows a draft in which the inner diameter and/or outer diameter of the sidewall530tapers in a proximal-to-distal direction.FIG.18shows a surface finish582applied to the sidewall530. As described herein, certain surface finishes may be intentional to manipulate the convergence and/or divergence of the electromagnetic radiation passing through the sidewall530. However, other surface finishes and/or inconsistently applied surface finished may adversely affect sensor readings.FIG.19shows an oval tube in which the inner diameter and/or outer diameter of the sidewall530are out of round.FIG.20shows a wisp584in the sidewall530, for example an inclusion in the base material or a molding line imparted during manufacturing. Each of the features shown inFIGS.16-20may cause the electromagnetic radiation passing through the fluid path section to behave in unexpected ways, which can result in spurious and unreliable output signals from the detector314. In empirical testing, differentiating between types of contrast media requires the most sensitivity, and as such the types of tubing irregularities shown inFIGS.16-20may have the most pronounced influence in this type of differentiation. Alternatively, differentiating between air and contrast media, air and saline, and contrast media and saline required less sensitivity, so tubing irregularities ofFIGS.16-20may have lesser or negligible effects on these determinations.

In some embodiments, the controller900may be configured to perform a test measurement prior to the injection and/or syringe filling procedure to establish the presence of and potential effects of these geometry features/defects on the output signals from the detectors314. The controller900may use the results of the test measurement to calibrate the detector314and/or to calculate one or more correction factors based in the effects of the features/defects in one or both the contrast injection fluid paths and the flushing fluid paths. During the filling and/or injection procedure, the controller900may apply the correction factor to the output signals from the detector314to compensate for the manufacturing feature/defects.

An additional manufacturing issue that can affect sensor readings is the inner diameter of the sidewall530being different from an expected value. This can occur due to manufacturing tolerances and/or the use of third party fluid path set components. An unexpected inner diameter of the sidewall530can particularly effect air bubble volume calculations, as the controller900may utilize a predetermined diameter constant corresponding to the inner diameter to convert the detected length of the air bubble into a volume. If the actual inner diameter of the sidewall530is different than predetermined diameter constant, the calculation of air bubble volume may be inaccurate. In some embodiments, the controller900may be configured to perform a test measurement prior to the injection procedure to establish the sidewall outer diameter, inner diameter, and thickness based on the detected refraction of the empty fluid path section. Based on the test measurement, the controller900may apply a correction factor to subsequent output signals from the detectors314.

Referring toFIGS.21A-21H, in some embodiments, the controller900may be configured to manipulate the intensity and/or wavelength of the electromagnetic radiation generated by the emitter312to enhance the sensitivity and/or gather additional information from the sensor310. In particular, the controller900may increase the current to the emitter312, causing the emitter312to emit light at a high intensity, or decrease the current to the emitter312, causing the emitter312to emit light at a lower intensity. In some embodiments, the controller900may power the emitter312at a predetermined intensity known to saturate the detector314. When the detector314is at its saturation limit, the output voltage of the detector314is at a maximum, and a further increase in the intensity of light from the emitter312will not produce a higher output voltage from the detector314.FIGS.21A-21Dillustrate detector output voltage as a function of emitter current for an arbitrary embodiment of the sensor310. As shown inFIG.21A, the detector314has a dark level, corresponding to minimum output voltage, and a saturation limit, corresponding to a maximum output voltage.FIG.21Aillustrates a first emitter current702, selected to produce a first detector output voltage802between the dark level and the saturation limit of the detector314.FIG.21Billustrates a second emitter current704that is greater than the first emitter current702, consequently causing the detector314to produce a second detector output voltage804greater than the first output voltage802. In this case, the second detector output voltage804is still below the saturation limit of the detector314.FIG.21Cillustrates a third emitter current706that is greater than the second emitter current704, consequently causing the detector314to produce a third detector output voltage806greater than the second detector output voltage804. In this case, the third emitter current706produces sufficient light intensity that the detector314is saturated, and thus the third detector output voltage806is at the saturation limit.FIG.21Dillustrates a fourth emitter current708that is greater than the third emitter current706. As the detector314has already reached its situation limit, a fourth detector output voltage808produced by the fourth emitter current708is substantially equal to the third detector output voltage806. Further increases in the emitter current will likewise not result in an increase in output voltage of the detector314.

The saturation limit for a given detector314is substantially constant. Because the refraction and absorption characteristics of the contents between the emitter312and detector314affect the amount and/or intensity of light that reaches the detector314, the refraction and absorption characteristics of the fluid in the fluid path section (and the fluid path section itself) will determine the emitter current required to reach the saturation limit of the detector314. The controller900may utilize the known saturation limit of the detector314to differentiate between fluids, e.g. air, saline, and contrast, and to differentiate between types and/or concentrations of contrast. For example, the controller900may drive the emitter312with a current that would be sufficient to saturate the detector314if only air was present in the fluid path section. If the detector output voltage does in fact reach the saturation limit in response to this emitter current, the controller900may determine that only air is present in the fluid path section. However, if the detector output voltage does not reach the saturation limit in response to this emitter current, the controller900may determine that another fluid is present. In some embodiments, the controller900may continue to modulate the current to the emitter312to further deduce the type and/or concentration of fluid in the fluid path section. For example, the controller900may drive the emitter312with a current that would be sufficient to saturate the detector314if the fluid in the fluid path section included less than a predetermined ratio of contrast to saline. If the detector output voltage reached the saturation limit in response to this emitter current, the controller900may determine that the fluid in the fluid path section has less than the predetermined ratio of contrast to saline

FIGS.21E-21Hillustrate this method of determining fluid content of the fluid path section by incrementally increasing emitter current. InFIG.21E, the controller900drives the emitter312at a fifth emitter current750, corresponding to a known current that will not saturate the detector314even if only air is present in the fluid path section. At this emitter current, a detector output voltage associated with air850, a detector output voltage associated with a first contrast solution852, a detector output voltage associated with a second contrast solution854, and a detector output voltage associated with a third contrast solution856are all below the saturation limit of the detector314. Nevertheless, the detector output voltage associated with air850is sufficiently differentiated from the detector output voltages associated with the contrast solutions852,854,856that the controller900may be able to conclude, based on the actual measured detector output voltage of the detector314, that air is present in the fluid path section. It is noted that at the fifth emitter current750), detector output voltages associated with the second contrast solution and the third contrast solution854,856are substantially at the dark level of the detector314, and therefore controller900cannot effectively differentiate between the second and third contrast solutions854,856at the fifth emitter current750.

Referring toFIG.21F, the controller900may increase the current to the emitter312in order to improve the ability to differentiate between the fluids, particularly the first, second, and third contrast solutions852,854,856. To do so, the controller900may drive the emitter312at a sixth emitter current752greater than the fifth emitter current750. At the sixth emitter current752, the detector output voltage associated with air850is at the saturation limit of detector314. The detector output voltage associated with the second contrast solution854has moved out of the dark level and is therefore within the effective resolution of the detector314. At the sixth emitter current752, controller900may be able to differentiate between particularly the first and second contrast solution852,852, based on the actual output voltage of detector314. Further, by a method of elimination, contrast solution856may be eliminated as if still falls within the dark level.

Referring toFIG.21G, the controller900may again increase the current to the emitter312in order to improve the ability to differentiate between the fluids, particularly the second and third contrast solutions854,856. At a seventh emitter current754, the detector output voltages associated with air850and first contrast solution852are at the saturation limit of the detector314. The detector output voltage associated with the third contrast solution856has moved out of the dark level. In addition, the spread between the detector output voltages associated with the second and third contrast solution854,856has increased, making differentiation between the second and third contrast solution854,856easier and/or more reliable at the seventh emitter current754compared to the sixth emitter current752.

The controller900may again increase the current to the emitter312to an eighth emitter current758. At the eight emitter current758, the detector output voltages associated with air850, first contrast solution852, and second contrast solution854are at the saturation limit of the detector314. Thus, controller900may be able to determine that the third contrast solution856is present in fluid path section if the actual detector output voltage of detector314is any value below the saturation limit. Controller900may be configured to incrementally modulate the current diving the emitter312at predetermined time intervals to analyze the fluid content of the fluid path section as described in connection withFIGS.21A-21H.

Referring toFIG.22, a graph of exemplary output signals of the detector314is shown for the sensor310arranged in operative association with syringe tips16A,16B (as shown inFIG.7orFIG.24) of three difference internal diameters (Syringe cap “A” of 0.122 inches, Syringe cap “B” of 0.165 inches, and Syringe cap “C” of 0.210 inches). Tests were performed for each of Syringe Caps “A”, “B”, and “C” for three different conditions: the syringe cap not in operative association with the sensor module300A,300B; the syringe cap in operative association with the sensor module300A,300B and filled with air; and the syringe cap in operative association with the sensor module300A,300B and filled with water. The output signals from the detector314allow the controller900to discriminate between these three conditions regardless of the internal diameter of the syringe cap. Across measurements taken for all three syringe cap diameters, the mean output signals for the syringe cap not in operative association with the sensor ranged from 4.110 to 4.111 volts; the mean output signals for the syringe cap filled with air ranged from 2.120 to 2.665 volts; and the mean output signals for the syringe cap filled with water ranged from 1.102 to 1.283 volts. For the test results shown inFIG.22, the emitter312operated at a wavelength of 1450 nm.

While various examples of the present invention were provided in the foregoing description, those skilled in the art may make modifications and alterations to these examples without departing from the scope and spirit of the disclosure. Accordingly, the foregoing description is intended to be illustrative rather than restrictive. The disclosure described hereinabove is defined by the appended claims, and all changes to the disclosure that fall within the meaning and the range of equivalency of the claims are to be embraced within their scope.