Flow sensor system comprising a transmission connection

Abstract

A flow sensor subassembly includes a flow tube having a lumen, an outer diameter, a first end, and a second end. An inlet fitting includes a conical bore sized for insertion into either end of the flow tube such that an internal passage of the inlet fitting is coaxial and concentric with the lumen and the end of the flow tube abuts a shoulder. An outlet fitting includes a conical bore sized for insertion into either end of the flow tube such that an internal passage of the inlet fitting is coaxial and concentric with the lumen and the end of the flow tube abuts a shoulder. A first piezoelectric element is disposed at an upstream location of the flow tube assembly integrated with the inlet fitting and a second piezoelectric element is disposed at a downstream location of the flow tube assembly integrated with the outlet fitting.

Description

[0001] Case Analysis

[0002] This invention patent application is a divisional patent application.

[0003] The original parent application for this divisional patent application is an invention patent application with an international filing date of August 25, 2016, international application number PCT / US2016 / 048689, Chinese national application number 201680050020.7, invention title "Flow Sensor System Including Transmission Connector", and firm file number IIM180249.

[0004] The direct parent application of this divisional application is the first-generation divisional application of the aforementioned most original parent application. The first-generation divisional application was filed on July 26, 2021, with divisional application number 202110841374.6, invention title "Flow Sensor System Including Transmission Connector", and office file number IIM211929.

[0005] On July 25, 2022, the State Intellectual Property Office issued a First Examination Opinion (hereinafter referred to as "Opinion") regarding the first-generation divisional application, pointing out that several claims of the first-generation divisional application lacked unity of claim. The applicant deleted these claims in its response to the Opinion. The Opinion is the direct basis for this (second) divisional application.

[0006] Interactive reference for related applications

[0007] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 211,108, filed August 28, 2015, the entire disclosure of which is incorporated herein by reference. Technical Field

[0008] This disclosure generally relates to a flow sensor system. More specifically, this disclosure relates to a flow sensor system for delivering medication to a patient via intravenous bolus (or "single rapid injection"), the flow sensor system providing healthcare professionals with automatic recordings of the medication, concentration, volume, dose, and time of each injection. Preferably, the system incorporates an ultrasonic flow sensor. Background Technology

[0009] Minimizing medication errors at the bedside is crucial during bolus administration. Providing recording and electronic measurement of bolus administrations would be beneficial, allowing for monitoring and automated documentation of administrations as part of the patient's health record. Additionally, providing alerts when an impending bolus administration is inconsistent with the patient's medical records would be advantageous. Summary of the Invention

[0010] This disclosure provides a system for sensing the flow of a fluid pharmaceutical agent. The system includes a smart injection port that can be attached to an injection site (e.g., a "Y-site" or stop cock) for manual IV injection. The system includes two main sub-components: a disposable flow sensor and a reusable base unit, which mate together before use.

[0011] According to one embodiment of the present invention, a flow sensor subassembly for sensing the flow of a fluid agent includes a flow tube assembly through which the agent flows, the flow tube assembly having a flow tube having a lumen, an outer diameter, a first end, and a second end. The flow sensor subassembly further includes an inlet fitting having a conical orifice with a shoulder having a matching size and orientation to match the end of the flow tube, wherein the conical orifice is sized for insertion into either end of the flow tube such that the internal channel of the inlet fitting is coaxial and concentric with the lumen and the end of the flow tube abuts the shoulder. The subassembly further includes an outlet fitting having a conical orifice with a shoulder having a matching size and orientation to match the end of the flow tube. The conical orifice is sized for insertion into either end of the flow tube such that the internal channel of the inlet fitting is coaxial and concentric with the lumen and the end of the flow tube abuts the shoulder. The flow sensor subassembly further includes a first piezoelectric element disposed upstream of the flow tube assembly and a second piezoelectric element disposed downstream of the flow tube assembly. A first piezoelectric element is integrated into the inlet fitting, and a second piezoelectric element is integrated into the outlet fitting, with each piezoelectric element spaced apart from each other at a predetermined distance. Each conical orifice has an inner diameter and a taper to engage with the outer diameter of the flow tube, thereby allowing capillary insertion of the adhesive during assembly.

[0012] The flow sensor subassembly may include an absorber sheath surrounding the flow tube, wherein the absorber sheath is made of a different material than the flow tube. The absorber sheath may be heat-shrinkable to the outer diameter of the flow tube. Alternatively, the absorber sheath may be adhered to the flow tube. Alternatively, the absorber sheath may be insert-molded around the flow tube.

[0013] The first and second piezoelectric elements may have an annular shape and surround each corresponding fitting at each respective mounting point. The internal channel of the inlet or outlet fitting is tapered and terminates at an end opposite the shoulder to engage the lumen of the flexible tubing.

[0014] In some configurations, a flow tube assembly is housed within a flow sensor housing having circuitry that engages with a piezoelectric element. The flow sensor housing is coupled to a flow sensor base containing a microprocessor, and the circuitry includes connecting pins for providing electrical signals from the flow sensor subassembly to the microprocessor within the flow sensor base. The flow sensor subassembly can be discarded after it has been used to sense the flow of at least one fluid agent. In some configurations, the flow sensor base can be used with different flow sensor subassemblies.

[0015] The internal channel of the inlet fitting may be tapered and terminate at an end opposite the shoulder to engage a Luer-type fitting. The internal channel of the inlet fitting may be tapered and terminate at an end opposite the shoulder with an inverted conical section. The conical orifice may be tapered, and both the inlet and outlet fittings may be two-part tapered, having a central shoulder approximately halfway along the length of the taper.

[0016] According to one embodiment of the present invention, a method for assembling a flow sensor subassembly for sensing the flow of a fluid pharmaceutical agent includes the following steps: providing a flow tube having a lumen, an outer diameter, a first end, and a second end, and providing an inlet fitting with a conical orifice having a shoulder having a matching size and orientation to match the end of the flow tube. The method further includes the steps of: inserting the flow tube into the conical orifice of the inlet fitting until the end of the flow tube abuts the shoulder of the inlet fitting, and providing an outlet fitting with a conical orifice having a shoulder having a matching size and orientation to match the end of the flow tube. The method further includes the steps of: inserting opposite ends of the flow tube into the conical orifice of the outlet fitting until the opposite ends of the flow tube abut the shoulder of the outlet fitting. Additional steps of the method include: attaching a first piezoelectric element to an inlet fitting, attaching a second piezoelectric element to an outlet fitting, applying an adhesive to the gap between the outer diameter of the flow tube and the inner diameter of the conical orifice on the inlet fitting, thereby allowing capillary wicking of the adhesive, and applying an adhesive to the gap between the outer diameter of the flow tube and the inner diameter of the conical orifice on the outlet fitting, thereby allowing capillary wicking of the adhesive.

[0017] Optionally, the method may further include: inserting a flow tube into an absorber sleeve surrounding the flow tube, wherein the absorber sleeve is made of a different material than the flow tube. An additional step of the method may include: inserting the flow tube into the absorber sleeve surrounding the flow tube, and heating the absorber sleeve to shrink it to the outer diameter of the flow tube. The absorber sleeve may be adhered to the flow tube. Optionally, the method may include: inserting a molded absorber sleeve around the flow tube.

[0018] The absorber material can be any polymer or elastomer, such as polyvinyl chloride, silicone rubber, and the like. In one embodiment, the absorber material can be inherently flexible and have a lower stiffness than the flow tube's durometer. By providing an absorber with a stiffness different from and lower than the flow tube's durometer, vibrations are contained within the absorber rather than transmitted into the flow tube.

[0019] In other configurations, the method may further include the steps of inserting an inlet fitting into an opening in a first piezoelectric element and inserting an outlet fitting into an opening in a second piezoelectric element. The method may also include the step of attaching a flexible tube to opposite ends of the internal channels of the inlet or outlet fitting. Attached Figure Description

[0020] The above and other features and advantages of this disclosure, as well as the ways in which they are obtained, will become more apparent from the following description of embodiments of this disclosure with reference to the accompanying drawings, in which:

[0021] Figure 1 This is a perspective view of a flow sensor system pointing to the distance according to an embodiment of the present invention.

[0022] Figure 2 This is a perspective view of a flow sensor system pointing towards the proximal side according to an embodiment of the present invention.

[0023] Figure 3A This is a near-front view of a flow sensor system according to an embodiment of the present invention.

[0024] Figure 3B This is a remote front view of a flow sensor system according to an embodiment of the present invention.

[0025] Figure 4A This is a side view of a flow sensor system according to an embodiment of the present invention.

[0026] Figure 4B As shown in detail A Figure 4A A magnified detail of a portion.

[0027] Figure 5A This is a perspective view of the base of a flow sensor system according to an embodiment of the present invention.

[0028] Figure 5B yes Figure 5A A perspective view of the base, showing the optical and electrical components.

[0029] Figure 6 This is a perspective view of a flow sensor in a flow sensor system according to an embodiment of the present invention.

[0030] Figure 7 This is another perspective view of the flow sensor in a flow sensor system according to an embodiment of the present invention.

[0031] Figure 8 This is an exploded perspective view of the flow sensor in a flow sensor system according to an embodiment of the present invention.

[0032] Figure 9 This is a perspective view of a flow sensor in a flow sensor system according to an embodiment of the present invention.

[0033] Figure 10A This is a side view of a syringe compatible with a flow sensor system according to an embodiment of the present invention.

[0034] Figure 10B As shown in detail B Figure 10A A magnified detail of a portion.

[0035] Figure 10C This is a side view of a prompt label for a syringe compatible with a flow sensor system according to an embodiment of the present invention.

[0036] Figure 11A This is a perspective view of a charger used in a flow sensor system according to an embodiment of the present invention.

[0037] Figure 11B It rotates clockwise as shown in detail C. Figure 11A A magnified detail of a portion.

[0038] Figure 11C This is a top view of a charger used in a flow sensor system according to an embodiment of the present invention.

[0039] Figure 11D It is along Figure 11C A cross-sectional view taken by line XX, according to an embodiment of the present invention, shows that the base of the flow sensor system is received within a portion of the charger.

[0040] Figure 12 This is a perspective view of a flow sensor and mounting component according to an embodiment of the present invention.

[0041] Figure 13 This is a perspective view of a flow tube assembly according to an embodiment of the present invention.

[0042] Figure 14A This is a schematic diagram of a computer display in anesthesia view according to an embodiment of the present invention.

[0043] Figure 14B This is a schematic diagram of a computer display in a table view according to an embodiment of the present invention.

[0044] Figure 15 This is a schematic side view of the process of applying an adhesive to a transducer, end fitting, and absorber sheath according to an embodiment of the present invention.

[0045] Figure 16 This is a perspective sectional view of an inlet fitting according to an embodiment of the present invention.

[0046] Figure 17 This is a perspective sectional view of an export fitting according to an embodiment of the present invention.

[0047] Figure 18 This is a cross-sectional side view of an injection port according to an embodiment of the present invention, the injection port being engaged with an inlet fitting, the inlet fitting being engaged with a transducer and an absorber.

[0048] Figure 19 This is a cross-sectional side view of an outlet fitting that engages with a transducer and an absorber according to an embodiment of the present invention.

[0049] Figures 20A to 20D The process for applying an absorber sheath and end fittings to a flow tube according to an embodiment of the present invention is illustrated.

[0050] Figures 21A to 21D The process for applying an absorber sheath and end fittings to a flow tube according to an embodiment of the present invention is illustrated.

[0051] Throughout the various views, corresponding reference characters denote corresponding components. The examples set forth herein illustrate exemplary embodiments of this disclosure, and such examples are not to be construed as limiting the scope of this disclosure in any way. Detailed Implementation

[0052] The following description is provided to enable those skilled in the art to make and use the embodiments contemplated for carrying out the invention. However, various modifications, equivalents, variations, and alternatives will readily be apparent to those skilled in the art. Any and all such modifications, equivalents, variations, and alternatives are intended to fall within the spirit and scope of the invention.

[0053] For the purposes of the following description, the terms “upper,” “lower,” “right,” “left,” “vertical,” “horizontal,” “top,” “bottom,” “lateral,” “longitudinal,” and their derivatives shall be used in connection with the invention, as oriented as shown in the accompanying drawings. However, it should be understood that the invention can take various alternative variations unless expressly stated otherwise. It should also be understood that the specific devices shown in the drawings and described in the following specification are merely illustrative embodiments of the invention. Therefore, the specific dimensions and other physical characteristics relating to the embodiments disclosed herein should not be considered limiting.

[0054] As used herein, "proximal" refers to the part or direction furthest from or away from the patient (upstream), while "distal" refers to the part or direction closest to or towards the patient (downstream). Furthermore, "medicinal substance" is used herein in an illustrative and non-limiting manner to refer to any substance that can be injected into a patient's body for any purpose. The term "patient" can refer to any living being, human, or animal. The term "clinician" can refer to any person or thing that administers treatment, such as a nurse, doctor, machine intelligence, caregiver, or even self-treatment.

[0055] Figures 1 to 12 An exemplary embodiment of the flow sensor system 200 of this disclosure is shown. (Refer to...) Figures 1 to 12 The flow sensor system 200 disclosed herein includes two main components that mate together before use: a flow sensor 210 and a base 220. In one embodiment, the flow sensor 210 may be a single-use flow sensor that can engage with a reusable base 220. The flow sensor system 200 is a smart injection port. The flow sensor system 200 may be attached to an injection site (e.g., a "Y site" or latch) for manually administered IV injections.

[0056] The flow sensor system 200 of this disclosure can reduce medication errors at the bedside during bolus delivery. The flow sensor system 200 of this disclosure can also provide recording and electronic measurement of bolus delivery, which allows for monitoring of bolus delivery and automatic documentation of bolus delivery as part of the patient's health record. The flow sensor system 200 of this disclosure can also provide an alarm when an impending bolus delivery is inconsistent with the patient's medical record.

[0057] Reference Figures 1 to 5BIn one embodiment, the base 220 is a non-sterile, reusable device that houses a battery, scanner (optical, mechanical, inductive, capacitive, proximity, or RFID), electronics, and a wireless transmitter. In some embodiments, the base 220 is battery-powered and rechargeable. In some embodiments, each base 220 has a unique serial number embossed on or embedded in its surface, which can be transferred to a data system prior to use. The data system may be a local computer or tablet "computer," a mobile phone, other medical devices, or a hospital data system.

[0058] In one embodiment, the base 220 can be detachably connected to the flow sensor 210. (See reference...) Figure 5A and Figures 6 to 9 This describes the base member 220 and the mechanical connection between the flow sensor 210 and the base member 220. The base member 220 includes at least one deflectable flap 280 defining an opening for receiving at least a portion of the flow sensor 210 therein and for securing the flow sensor 210 within a portion of the base 220 before use. In one embodiment, a pair of flaps 280 secure the flow sensor 210 within the base 220. Optional clamping ribs 395 may be provided on the outer profile to allow a user to grip the base portion 220.

[0059] The inner surface of the vane 280 may be provided with a capturing part 389 for corresponding engagement with the protrusion 189 provided on the flow sensor 210, such as in Figure 6 As shown, the flow sensor 210 is constrained within the base 220, as will be further described herein. The vane 280 may be flexible enough to allow the flow sensor 210 to pass over it by deflecting outwards. A pin cam 388 may be provided internally within the vane 280, as... Figure 7 The pin 188 of the flow sensor 210 shown is allowed to travel along it, so that the flow sensor 210 is moved proximally during assembly onto the base 220 to precisely align the flow sensor 210 and the various optical and electrical components of the base assembly 220, as will be further described herein.

[0060] Reference Figure 5B and Figures 6 to 9 This describes the base component 220 and the electrical connection between the flow sensor 210 and the base component 220. The base 220 includes an activation / engagement button 350, which allows indication that the flow sensor 210 has been engaged with the base 220. In one embodiment, the activation / engagement button 350 signals a microprocessor within the base 220 to notify that the syringe has been properly engaged with the sensor 210 and its injection port 130.

[0061] The base 220 also includes multiple contacts 386 ( Figure 5B ), used for electrically engaging multiple contact pins 385 ( Figure 7 The corresponding electrically active portion of ). The contoured protrusion 488 surrounds at least a portion of the tongue 286. For example Figure 7 As shown, the bottom surface of sensor 200 includes a pin seal 384 that surrounds a plurality of pins 385 to prevent contamination, thereby minimizing electrical interruptions. In some embodiments, the plurality of pins 385 includes a four-pin connector having two pins electrically connected to each piezoelectric element 150, 151, as will be discussed further. In other embodiments, the plurality of pins 385 includes a six-pin connector having two pins electrically connected to each piezoelectric element 150, 151 and two pins electrically connected to a battery (not shown) in flow sensor 210.

[0062] The base component 220 also includes a tongue 286 surrounded by a shoulder 486, the tongue 286 having a plurality of contacts 386 for electrically engaging the sensor 200 and the charger 900. Figure 11A The corresponding electroactive portion of ), as will be described herein.

[0063] Reference Figures 1 to 4B , Figures 6 to 9 as well as Figure 13 In one embodiment, the flow sensor 210 is a pre-sterilized, disposable device with an injection port 130 and a distal tubing connection, such as a Luer tip 109.

[0064] The flow sensor 210 may include a flow tube assembly 10 consisting of a flow tube 100 having an outlet end 101 and an inlet end 102. The outlet end 101 may be configured to be in fluid communication with an outlet tube 110 having an outlet connector 105 including a Luer tip 109, which may optionally be covered by a Luer cap 108. In a preferred embodiment, the outlet connector 105 is a plastic connector with a Luer tip 109; however, any suitable method of injecting a drug into a patient is contemplated within one aspect of an embodiment of the invention. For example, it would be desirable to replace the outlet connector 105 and the tube 110 with a needle for direct injection / infusion into a patient. Furthermore, it would be desirable to integrate the base 220 into a drug pen or infusion device for delivering insulin.

[0065] The inlet end 102 can be coupled to the reservoir or infusion reservoir of the medication pen. The inlet end 102 of the tubing 100 can be configured to be in fluid communication with the injection port 130 and may optionally include a connector, such as a threaded Luer lock 131 that engages with a source of the fluid to be injected. A puncture-resistant diaphragm 139 may be provided with the injection port 130 to maintain sterility prior to use.

[0066] In a preferred embodiment, injection port 130 is a plastic container with a split diaphragm 139; however, within one embodiment of the invention, any suitable method for injecting the medication into the patient via flow sensor inlet 180 is contemplated. For example, it would be desirable to replace injection port 130 for direct connection to a medication delivery device. Additionally, it would be desirable to integrate flow sensor inlet 180 to accept direct fluid connection to a medication delivery device.

[0067] In one embodiment, the flow tube 100 is made of medical-grade stainless steel and has a length of approximately 50 mm, an inner diameter of 1.0 mm, and an outer diameter of 1.6 mm.

[0068] The flow sensor 210 also includes a first piezoelectric element or upstream transducer 150 and a second piezoelectric element or downstream transducer 151. The first piezoelectric element 150 may be provided with an inlet fitting 180, such as... Figure 8 As shown, it is used for connection to injection port 130. Similarly, the second piezoelectric element 151 may be provided with outlet fitting 190 for connection to outlet tube 110.

[0069] Flow sensor 210 can be supplied in sterile packaging for single-patient use. In one embodiment, a label is printed on a separate sterile package. In one embodiment, each flow sensor 210 has a unique serial number embossed on a portion of its surface. In some embodiments, electronics are present in the flow sensor 210 to maintain a unique identifier. These identifiers are automatically or manually transmitted to a data system during use and data collection. In one embodiment, at the inlet end 102 of the flow sensor 210, the injection port 130 is a common needle-free Luer-Lok type. Typically, the inlet port or injection port 130 is cleaned before administration according to hospital policy. Additionally, it is desirable to flush the flow sensor 210 with IV fluid (e.g., a saline syringe) before use. The injection port 130 on the flow sensor 210 typically supports up to 100 injections. In one embodiment, the flow sensor 210 has a male Luer-Lok connector at the one-inch IV tubing tail end at the outlet end 101, for example, an outlet connector 105 with a Luer tip 109. The male Lurlock connector can be attached to the IV line at the Y-section or IV manifold. Each flow sensor 210 has a unique serial number; however, it is desirable to display only a portion of the serial number on a portion of the exterior of the flow sensor 210. For example, the last four digits of the serial number can be embossed on a surface next to its barcode. This human-readable number is used to visually identify the flow sensor 210 within the wireless communication range of a computer. In some embodiments, the flow sensor 210 measures with ±5% accuracy for injection volumes >1.0 mL to 55 mL and ±20% accuracy for injection volumes 0.4 mL to 1.0 mL, and has a dead space volume of less than 0.3 mL.

[0070] Reference Figures 11A to 11D In one embodiment, an optional separate charger 900 is compatible with the flow sensor system 200 and, if needed, recharges the battery in the reusable base 220 for reuse. See also... Figures 11A to 11D In one embodiment, the charger 900 includes a charger base 905 having an opening 925 for receiving a base 220, the opening 925 having charging pins 950 that engage with corresponding contacts 386 in the reusable base 220. The charger 900 may include a sloped base plate 930 to allow disinfectant to drain therefrom. The device may also include raised feet 999 to aid in drainage.

[0071] Reusable bases are typically supplied as non-sterile and require sterilization and charging before use. Preferably, each base 220 is sterilized before first use. Typical commercially available hospital disinfectants include alcohol-based quaternary ammonium compounds, such as Metrex Research Cavi Wipes. In some embodiments, the base 220 can be used up to 500 times. Preferably, a rechargeable lithium-ion battery is used within the base 220 and is not removable from the base 220. It is envisioned that a fully charged base 220 will be used throughout the patient's medical history. In some embodiments, each base 220 is identified by a label affixed to the bottom of the device. Optionally, the bases 220 are housed in separate cases, each case being part of the medical history package. The charger 900 may also include a power indicator 995. In one embodiment, up to four green light bars will illuminate on top when the base 220 is connected to the charger 900. The number of solid green light bars indicates the charging level. A flashing green light on base 220 indicates that it is charging. In some embodiments, when base 220 is connected to charger 900, a usable life indicator is employed by means of a red light (indicating that base 220 has exceeded its lifespan). Optionally, on a computer, an error message is displayed when a patient wirelessly connects their flow sensor system 200, which has reached the end of its lifespan, to a tablet computer during setup. It is then expected that base 220 be replaced with another base, and the wireless connection to the computer be repeated. Optionally, flow sensor system 200 is housed in a mounting device that mates with a standard Clarke socket to hold flow sensor system 200 in a suitable position at the patient's bedside. Additionally, it is expected that charger 900 be cleaned and disinfected using a procedure for cleaning and disinfecting base 220.

[0072] In one embodiment, the flow sensor system 200 uses any Luer-lock syringe to support injection. For example, see reference... Figures 10A to 10C The flow sensor system 200 is compatible with the labeled syringe 800. In one embodiment, the syringe 800 includes a scale mark 805, a distal tip 810, a Luer tip 815, a proximal end 820, a flange 825, a cue label 850 with human-readable markings 852 and machine-readable markings 854, a tube label 860 with human-readable markings 862, and a plunger 890.

[0073] The base 220 of the flow sensor system 200 includes a first window 360 (as shown in...) Figure 2The optics and digital camera (shown in Figure 5) located within or behind the syringe 800 are capable of reading the machine-readable mark 854 provided on the label 850 of the coded syringe. When the flow sensor 210 is assembled with the base 220, the first window 360 can be precisely aligned with the Luer lock thread 131 present on the flow sensor 210, thereby aligning the machine-readable mark 854 present on the label 850 on the syringe 800 during injection cycles and / or drug determination cycles. The base 220 may also include a second window 370 with a light source, as shown in Figure 5, for providing sufficient illumination to the camera arranged within or behind the window 360.

[0074] Additionally, the flow sensor system 200 is designed to work with coded syringes that have a specific barcode identifier on the Luer collar of the syringe, referred to as "coding". Preferably, the coded syringe contains a commercially available drug in a pre-filled syringe with a specific barcode storing information about the drug contained in the syringe. The coded syringe is ready-to-use, passive, and disposable. The flow sensor system 200 is also adapted to syringes without coding. The coded syringe stores the name and concentration of the drug contained in the syringe. Additional characteristics, such as drug source, container size, manufacturer, drug category, color, etc., may also be included. When the coded syringe is attached to the injection port 130 of the flow sensor 210, the barcode information is read by a scanner in the base 220 and wirelessly transmitted by the flow sensor system 200 to a data system. Preferably, a 2-D barcode is added to the syringe during the filling process.

[0075] In one embodiment, the flow sensor system 200 includes means for capturing and transmitting an image of a 2-D barcode on the Luer collar of the syringe, and wirelessly transmitting the image to a “computer.” Typically, this computer is a tablet computer that communicates with multiple flow sensor systems 200. The 2-D barcode contains data, typically including the name and concentration of the drug in the syringe, as well as other data. The computer decodes the image and displays and informs the user of the attached drug. The barcode may contain the drug name and concentration. As the drug is injected, a flow sensor 210, in conjunction with a base 220, ultrasonically measures the volume of the injected drug and the time of administration. This information may be stored in the flow sensor system 200 for later transmission to the computer. The computer uses this information to provide clinicians with an automatic record of the drug name, concentration, volume, dosage, and injection time. The drug administration information is timestamped and displayed for clinical reference. Not all syringes used by healthcare professionals contain 2-D barcodes. If a syringe without a 2-D barcode is inserted into the flow sensor system, the injection port 130 and flow sensor system 200 will prompt the user to manually enter the drug name and concentration into the computer. The information manually entered into the flow sensor system 200 is included in the patient's medication record.

[0076] In one embodiment, the computer can use a radio to wirelessly communicate with the flow sensor system 200 using RF signals at 2.4 GHz to form a local medical device network. Multiple flow sensor systems 200 and computers can be used in the same area, for example, a preoperative care area or a post-anesthesia care unit (PACU). Alarm messages are transmitted between the flow sensor system 200 and the computer to advise clinicians on various operational characteristics of the flow sensor system 200. Some of these alarms inform clinicians of potential hazards, allowing users to take action to prevent harm to the patient or loss of medical data. Preferably, a wireless communication loss message is displayed when communication between the flow sensor system 200 and the computer is lost. Preferably, all medication administration data from the flow sensor system 200 is transmitted to the specific patient's medical record. In the event of a communication loss, the medication administration data is stored locally at the flow sensor system 200 and transmitted to the computer when communication is restored.

[0077] The computer can operate in various modes. Typically, it features a dedicated flow sensor system 200 software, a touchscreen, and wireless communication (radio). The computer is typically mounted near the anesthesiologist's or nursing work bag, and it can be removed for handheld use. When used in hospitals with paper-based anesthesia records, the computer supports functions that assist in archiving flowchart sections and can help clinicians make informed decisions. In this configuration, the computer supplements paper record keeping activities by tracking and displaying injections given through the flow sensor system 200. The computer also enables clinicians to manually archive other relevant IV medication and infusion information.

[0078] In one embodiment, the software screen follows a three-step method consisting of: (1) connecting the flow sensor system 200 to a computer; (2) setting up the patient's flow sensor system 200 for use; and (3) viewing the drug administration in multiple views.

[0079] In some embodiments, the view on the computer displays anesthesia-based information in the anesthesia view, such as in... Figure 14A As shown in the diagram. Preferably, this view provides information about the patient and displays the name / concentration and dosage of the medication used for the current injection, as well as a historical list of medications administered to the patient since the current case was opened. The view also includes a list of infusions given to the patient, if the clinician has recorded such a list on a computer. In this view, up to three injection strips are displayed across the top of the screen, one corresponding to each wirelessly connected flow sensor system 200. Each injection strip is a real-time representation of medication administered via a separate flow sensor system 200. When an coded syringe is attached to a single flow sensor system 200, the injection strip displays the medication name and concentration. When a non-coded syringe is attached, the injection strip prompts the clinician to identify the medication being administered and its concentration. As the medication is being administered, the volume pushed (in mL) and the corresponding dose are displayed in real-time on the injection strip on the computer monitor.

[0080] The flow sensor system 200 of this disclosure can also provide optional medication history. For example, an anesthesia view may include a history list of medications administered to the patient, organized by surgical care areas arranged in a flowchart format (medications given during transitions between care areas will be issued to the next care area). Preferably, the view includes all medications administered to the patient since the flow sensor system 200 was activated with a more recent medication at the bottom of the list. A scroll bar is enabled when the list exceeds the visible space on the computer screen. Preferably, the medication list scrolls automatically as a new medication is added, making the new medication name visible. In the view, preferably, a color planar image corresponding to the American Society for Testing and Materials (ASTM) standard and approved by the American College of Anesthesiologists is displayed to the left of the medication name. Optionally, the clinician may also specify the administration of admixtures (mixed medications) or diluted or reconstituted medications. Optionally, the computer displays a case title listing the patient's name, date of birth, age, medical record number, and patient identification number. Optionally, the computer will indicate that the patient has an "unknown allergy." Preferably, if the patient has allergies, the text is changed via a button; more preferably, the button has a number indicating the number of allergy symptoms.

[0081] like Figure 14B As shown, the flow sensor system 200 of this disclosure can also provide an optional tabular view. For example, a tabular view is an alternative view for enabling clinicians to interact with the flow sensor system 200. Similar to the anesthesia view described above, this view provides information about the patient and displays the name / concentration and dose of the drug used for the current injection, as well as a historical list of drugs already administered to the patient. The view may also include a list of infusions given to the patient, if recorded by the clinician. The tabular view has many of the features of the anesthesia view; however, the tabular view is arranged in a tabular format. Preferably, the column headers in this view include administration time, drug concentration, dose, and total unit dose. Optimally, drugs are displayed in reverse chronological order, with the most recent drug at the top of the list.

[0082] In one embodiment, the computer provides two types of messages: (1) "clinical" and (2) "system". Clinical messages are alerts and reminders that directly relate to aspects of patient care services (e.g., contraindications or reminders, which could be the timing of re-administration of antibiotics). System messages provide status information about relevant system operating parameters.

[0083] The messages provide instructions and buttons for confirmation or resolution. Messages are displayed on the computer until they are confirmed or no longer clinically relevant. Messages can be answered at any time during the case. Clinicians are prompted to respond to / answer unresolved medication messages generated during the case before pausing or closing it. When a clinician attaches a coded syringe or selects a medication for a non-coded syringe for a patient with a known allergy, an allergy alarm illuminates the flow sensor system 200 and is displayed on the computer. Optionally, the message can be ignored.

[0084] When antibiotics are administered, preferably, the computer tracks the time elapsed since the last antibiotic administration and displays and notifies the user of an antibiotic re-administration message if the configured re-administration interval has elapsed. The re-administration interval is individual for each antibiotic and is configured in a drug database on the computer or gateway, as further described below. In one embodiment, the flow sensor system 200 does not block or obstruct drug injection. In other embodiments, the flow sensor system 200 is capable of obstructing drug injection.

[0085] In one embodiment, a computer issues a message when the volume injected through the flow sensor system 200 is not measured. This occurs when the measured volume is outside the sensing range of the flow sensor system 200.

[0086] Optionally, the computer and software application communicate wirelessly in both directions, the software application acting as a central hub, or "gateway," connecting to all computers (and thus multiple computers across the multiple flow sensor systems 200). Preferably, the gateway is also connected to other networked information systems within the hospital. The gateway allows all computers to share patient medical information, such as drug names, dosages, and delivery times, via the hospital's networked information systems. The gateway also allows computers to receive patient information from other networked hospital information systems, such as patient drug allergies and patient medication sequences.

[0087] Utilization of the flow sensor system 200 of this disclosure includes the step of connecting the flow sensor 210 to a patient's catheter or injection port (Y site). Preferably, the flow sensor 210 and the tubing are flushed. The flow sensor 210 is assigned a unique serial number to each patient, and the base 220 records drug administration through a port at the inlet end 102 of the flow sensor 210.

[0088] When syringe 800 is connected to injection port 130, flow sensor system 200 identifies the drug and concentration used to encode the syringe by optically imaging and decoding the barcode on the Lurlock collar of syringe 800. This information is wirelessly transmitted to a computer. Preferably, the computer displays and audibly informs the user of the attached drug. The computer can also perform allergy safety checks based on the patient's medical records.

[0089] In one embodiment, as a drug is injected, the flow sensor system 200 ultrasonically measures the volume of medication administered. The flow sensor system 200 wirelessly transmits the volume measurement information to a computer. The computer uses this information to provide clinicians with a drug administration record, which is timestamped and displayed during surgical procedures for clinical reference. Manually entered infusions and other information related to non-coded drug injections can be included in the patient medication record in the computer and gateway. The computer wirelessly communicates with the gateway on the hospital network, and the computer can, when configured, transmit drug administrations to the hospital information system for reporting and electronic record keeping purposes. Preferably, the computer uses a standards-based IEEE 802.11a / b / g / n enterprise WLAN network to wirelessly communicate with the existing hospital network. The gateway software and accompanying database become part of the hospital's enterprise information system. Multiple computers can connect to the healthcare enterprise wireless network and the intended gateway software and database. Preferably, the gateway and accompanying database provide a patient list for user selection and a prescription library of drugs and fluids for injection or infusion. In one embodiment, actual drug and fluid administration data is transmitted to the gateway and accompanying database for record keeping. Once recorded in the gateway and accompanying database, this data is preferably available for use in other care areas when the patient is transferred and the flow sensor system 200 is wirelessly connected to the computer. Preferably, in the event of a communication failure, medication administration data will not be sent to the gateway and therefore will not be available in the next care area.

[0090] Reference Figures 1 to 12 The use of the flow sensor system 200 of this disclosure will now be described. First, the fabrication of the flow sensor system 200 for injection will be discussed.

[0091] In one embodiment, the flow sensor system 200 is prepared, attached to an IV line, and assembled for use. Preferably, pre-printed instructions are provided on the aseptic bag of the flow sensor 210. The user first receives the flow sensor 210 in its aseptic package, along with a fully charged and sterilized reusable base 220. In one embodiment, under typical conditions, the fully charged base 220 has sufficient power for operation for at least 24 hours. Optionally, the base 220 provides a visual indication of the charging level via a display.

[0092] Next, the flow sensor 210 is flushed with sterile IV fluid before being attached to the Y site. In one embodiment, the flow sensor 210 is flushed with more than 8 mL of sterile IV fluid. After flushing, the user can visually inspect the IV line to check for leaks, air, or blockages.

[0093] Next, the user first attaches the flow sensor 210 to the base 220 by connecting the flow sensor 210 (pipe side) and the front end of the base 220, and then by engaging the two together. Preferably, an audible crackling sound indicates a secure connection between the flow sensor 210 and the base 220. In one embodiment, connecting the flow sensor 210 to the base 220 automatically supplies power to the flow sensor system 200. In one embodiment, the connection from the flow sensor 210 to the base 220 is verified by a flashing light on the base 220. In other embodiments, other indicators may be used. The capture portion 389 of the base 220 shown in Figure 5 and Figure 6 The tab 189 of the flow sensor 210 shown engages to constrain the flow sensor 210 with the base 220 before injection begins. In one embodiment, deflection of the flap or multiple flaps 280 causes the tab 189 to move relative to the catch 389 to initiate engagement or disengagement. When the flow sensor 210 is assembled to the base 220, a cantilever 650 (e.g., the lower housing 212 discussed below) disposed on the base 220 aligns with a button 350 disposed on the base 220. A pin cam 388 may also be disposed internally within the flap 280, which allows for... Figure 6 The pin 188 of the flow sensor 210 shown is advanced along it, causing the flow sensor 210 to move proximally during assembly onto the base 220. During engagement, the tongue 286 shown in FIG. 5 is engaged. Figure 7 Within the opening 285 shown. Continuing to refer to Figure 5 and... Figure 7 ,like Figure 7 As shown in Figure 5, the dome 485 with ribs 487 on the flow sensor 210 has an outer profile corresponding to the profile obtained by means of the shoulder 486 of the base 220, so as to engage when the flow sensor 210 is assembled to the base 220 for precise alignment of the first window 360 with the Luer lock thread 131.

[0094] In some embodiments, where appropriate, the flow sensor system 200 is fixed to a surface during fabrication for use in dispensing injection. For example, in some embodiments, reference is made to... Figure 12 Secure the flow sensor system 200 to the surface using mounting bracket 1100. In this step, it is important to avoid kinks in the wiring between the flow sensor system 200 and the IV line.

[0095] The flow sensor system 200 is now ready to deliver IV medication. Preferably, any medication delivered by the flow sensor system 200 will be recorded in the memory of the electronic base 220. In one embodiment, in the event of a failure of the flow sensor system 200 (exclusion of the IV fluid path), the flow sensor system 200 will still allow the delivery of standard medication or fluid through the port.

[0096] Next, the use of the flow sensor system 200 to administer the injection will be discussed. First, the injection port 130 is cleaned via a wiping interface (hub) according to standard hospital procedures. Next, the syringe 800 is attached to the injection port 130 of the flow sensor 210 by fully rotating the syringe 800 until it stops, i.e., establishing a secure connection between the syringe 800 and the injection port 130 of the flow sensor 210. Ideally, caregivers double-check the name and concentration of each medication on the syringe 800 before attaching it to the injection port 130 to ensure the correct medication is administered. During the injection cycle and / or medication determination cycle, when the syringe tip 810 contacts... Figure 4B When the syringe protrusion 652 is shown, the cantilever 650 deflects radially from the longitudinal axis of the syringe 800. The pad protrusion 651 presses the button 350 on the base 220, and the button 350 signals the microprocessor to activate.

[0097] Next, the medication and concentration displayed and indicated by the computer are verified to be the expected medication and concentration. In one embodiment, if a drug allergy is detected, the base 220 will alert caregivers to the detection of an allergy via an alarm, for example, by flashing red, green, and yellow lights. Optionally, the computer calculates potential allergic reactions and provides an alarm when either of the following conditions is true: (1) a coded syringe is inserted into the flow sensor 210 and the medication matches the patient's allergy profile; or (2) a non-coded syringe is inserted into the flow sensor 210 and a medication matching the patient's allergy profile is selected from the medication selection screen. If one of these conditions is true, an allergy warning flag on the computer configuration will be activated.

[0098] In one embodiment, neither a check valve nor a human is required to safely and efficiently use the flow sensor 210. Typically, the flow sensor system 200 measures 0.4 mL to 55 mL per injection. If the injection flow rate is slow or the volume delivered is small (<0.4 mL), an alarm is preferably displayed on a computer. Optionally, the alarm is configured to detect rapid delivery from a syringe with a larger volume, such as 50 mL. In this case, an alarm is provided to check the dosage.

[0099] In one embodiment, indicator 375, such as a series of four LED indicators, is turned on sequentially to indicate to the user that fluid is flowing through flow sensor 210. When base 220 is mounted in charger 900, indicator 375 can indicate the battery charge level of base 220.

[0100] In one embodiment, it is preferable to flush the syringe with coded saline solution following the full drug injection via the flow sensor system 200, in order to ensure that the full dose of the drug reaches the patient, especially when two incompatible drugs are delivered sequentially. Optionally, the flow sensor system 200 records such saline flushing activities.

[0101] In one embodiment, the injection is recorded regardless of whether the flow sensor system 200 is wirelessly connected to a computer. The base 220 stores the injection information in its memory and transmits the information when wirelessly connected to a computer.

[0102] In one embodiment, the computer can accommodate multiple flow sensor systems 200 connected to a single patient at a time. Additional flow sensor systems 200 can be added at any time during patient treatment. When a flow sensor system 200 is connected to the computer and no syringe is attached to the flow sensor 210, the active injection strip reads "Sensor connected, no syringe". On the computer display, a battery status icon in the upper right corner of the injection strip indicates the battery charge level of the base 220 connected to the flow sensor 210. For each injection, a caregiver can enter comments on the computer.

[0103] This disclosure provides a flow sensor subassembly for sensing the flow of a fluid pharmaceutical agent. The flow sensor subassembly includes a first spring contact and a second spring contact. In one embodiment, the spring contacts are fixed to a base having circuitry for transmitting electrical signals from and to the spring contacts to a microprocessor. The first spring contact is in electrical communication with a first piezoelectric element, and the second spring contact is in electrical communication with a second piezoelectric element. The first spring contact has a first contact force against the first piezoelectric element, and the second spring contact has a second contact force against the second piezoelectric element, wherein the first contact force is equal to the second contact force. The invention also provides a circuit board for interfacing with a flow sensor having a plurality of piezoelectric elements for transmitting flow signals indicative of the flow of a fluid pharmaceutical agent.

[0104] The spring contacts of this disclosure provide electrical contact to the piezoelectric element. For example, the spring contacts of this disclosure provide electrical contact to the silver-plated surface of a piezoelectric crystal. Furthermore, this contact provides a spring force that is selected to accommodate assembly tolerances, temperature variations, electrical requirements, material selection for the long lifespan of silver, and assembly characteristics for single-sided printed circuit board assembly (PCBA) accessories. The flow sensor subassembly of this disclosure is provided to ensure that the four contacts used in the sensor have the same force on both surfaces of each of the two piezoelectric elements (e.g., crystals) in a single transducer.

[0105] The circuit board disclosed herein provides a single-sided PCBA. The single-sided PCBA of this disclosure offers a lower cost design than conventional double-sided PCBA designs. The circuit board of this disclosure also provides measures to maintain the mechanical load on the crystal contacts when the transducer is inserted into the PCBA.

[0106] Electrical contact with ultrasonic crystals has previously been achieved by soldering wires to a silver coating. The spring contacts of this disclosure offer a cost-reducing method by connecting spring contacts to the crystal. In particular, the single-sided printed circuit board (PCB) of this disclosure provides a lower-cost design for through-hole contact designs. The design of this disclosure includes the force applied multiplied by the spring constant, the separation dimensions between the contacts, the type of spring material, the required force range, and the tolerance control of the force applied by the spring contacts, all of which are important for eliminating soldering. If soldering overheats, the solder often removes silver from the crystal surface. Another problem with soldering is leaving too much solder behind, which can also contribute to the loading of ultrasonic physical properties. Consistent electrical and physical contact (repeatability) between the two crystals is as important as sensor-to-sensor calibration. The force cannot be too high (potentially developing slurry) or too low (variable impedance).

[0107] The flow sensor subassembly disclosed herein offers a high-volume, one-off design that benefits its cost, reliability, and repeatability. The flow sensor subassembly disclosed herein allows for use with future automation features. The flow sensor subassembly disclosed herein provides maximum tolerance for design under a wide range of conditions. The flow sensor subassembly disclosed herein can be fitted into the housing of flow sensor 210.

[0108] Reference Figure 8 and Figure 13The flow tube subassembly 10 of the flow sensor 210 for sensing the flow of a fluid medication typically includes a flow tube 100 through which the medication flows, having a flow tube inlet 102 and a flow tube outlet 101; a first piezoelectric element 150 disposed upstream of the flow tube 100 and a second piezoelectric element 151 disposed downstream of the flow tube 100; and a first spring contact 750 and a second spring contact 750. The flow tube inlet 102 may be connected to a reservoir or infusion reservoir of a medication pen. As described herein, in some embodiments, the inlet end 102 of the flow tube 100 may be configured to be in fluid communication with an injection port 130.

[0109] In one configuration, the sub-assembly 10 for the flow sensor 210 can be used as the flow sensor 210 and inserted into the base 220, wherein the contact 750 is integrated into the base 220, rather than being a component of the housings 211, 212 of the flow sensor 210. Preferably, the upstream transducer 150 and the downstream transducer 151 are interchangeable; however, it is contemplated that the upstream transducer 150 and the downstream transducer 151 can be purposefully configured for their respective positions on the flow sensor sub-assembly 10.

[0110] In one embodiment, the first piezoelectric element 150 and the second piezoelectric element 151 are mounted apart from each other at a predetermined distance. In one embodiment, each of the spring contacts 750 is fixed to a base, such as a circuit board 700. The circuit board 700 includes a means for transmitting electrical signals from and to the spring contacts 750 to a microprocessor. The first spring contact 750 is in electrical communication with the first piezoelectric element 150, and the second spring contact 750 is in electrical communication with the second piezoelectric element 151. The first spring contact 750 has a first contact force against the first piezoelectric element 150, and the second spring contact 750 has a second contact force against the second piezoelectric element 151. In one embodiment, the first contact force is equal to the second contact force. In another embodiment, the circuit board 700 may include non-volatile memory containing the serial number of the sensor 210, calibration data, and / or flow calculation constants for communication to an electronic microprocessor at the base 220.

[0111] Reference Figure 13 and Figure 15In one embodiment, the flow sensor 210 includes an internal flow tube 100 and end fittings, such as an inlet fitting 180 at an inlet end 102 and an outlet fitting 190 at an outlet end 101, for securing the internal flow tube to the respective end fittings 180, 190. In one configuration, a transducer 155 is coupled to at least one of the inlet fitting 180 and the outlet fitting 190. In another configuration, a transducer 155 is coupled to each of the inlet fitting 180 and the outlet fitting 190. In yet another configuration, a first piezoelectric element 150 is coupled to the inlet fitting 180, and a second piezoelectric element 151 is coupled to the outlet fitting 190.

[0112] Transducer adhesive 156 can be used to bond transducers 155, such as first piezoelectric element 150 and second piezoelectric element 151, to fittings 185, such as inlet fitting 180 and outlet fitting 190. Transducer adhesive 156 bonds transducers 155 to fittings such that energy from transducers 155 is optimally transmitted across transducer fitting transmission region 159 as indicated by arrow T, while minimizing losses at fitting tube transmission region 158, as indicated by arrow T1. Preferably, fitting adhesive 186 suppresses out-of-phase and / or rogue vibrations induced in end fittings 180, 190 by the transmission of acoustic energy between the first and second piezoelectric elements 150 and end fittings 151.

[0113] A first piezoelectric element 150 is disposed upstream of the flow tube 100, and a second piezoelectric element 151 is disposed downstream of the flow tube 100. The first and second piezoelectric elements 150 and 151 are configured to transmit a flow rate signal indicating the flow of a fluid agent in the flow tube 100. In one embodiment, the first and second piezoelectric elements 150 and 151 have annular shapes and surround the flow tube 100 at each corresponding mounting point. In one embodiment, the first and second piezoelectric elements 150 and 151 are mounted apart from each other at a predetermined distance. The first and second piezoelectric elements 150 and 151 are respectively mounted to end fittings 180 and 190. Each of the first and second piezoelectric elements 150 and 151 is bonded to the end fittings 180 and 190 by transducer adhesive 156, such that energy from the transducers 150 and 151 is optimally transmitted across the transducer fitting transmission area 159 of each end fitting 180 and 190. The adhesive can increase or maximize energy transfer across the transducer accessory transmission zone 159 while reducing or minimizing losses. Preferably, the transducer adhesive 156 facilitates the transmission of acoustic energy between the first piezoelectric element 150 and the second piezoelectric element 151 and the end accessories 180, 190. The transducer adhesive 156 can be a medical-grade adhesive of moderate viscosity. Air gaps between the first piezoelectric element 150 and the second piezoelectric element 151 and the end accessories 180, 190 can be eliminated to achieve more efficient acoustic energy transmission. Preferably, the transducer adhesive 156 retains its properties after sterilization.

[0114] Refer again Figure 13 and Figure 15 The absorber sleeve 500 may surround the flow tube 100. In some embodiments, there may be a gap between the absorber sleeve 500 and the inlet fitting 180 exposing a portion of the flow tube 100 at the inlet end 102, and / or there may be a gap between the absorber sleeve 500 and the outlet fitting 190 exposing a portion of the flow tube 100 at the outlet end 101. For example, the absorber sleeve 500 may be positioned approximately 6 mm away from the inlet fitting 180 and approximately 6 mm away from the outlet fitting 190. The absorber sleeve may comprise a material having an acoustic transmission rate different from that of the material of the flow tube 100. For example, the flow tube 100 may comprise stainless steel, and the absorber sleeve 500 may comprise a plastic material, PVC, an elastomer, a medical-grade silicone rubber material with a Shore A hardness of 70A, or a heat shrink tubing material.

[0115] In one embodiment, the absorber sheath 500 can be heat-shrinkable to the outer diameter of the flow tube 100. In another embodiment, such as Figure 15 As shown, the absorber sheath 500 is adhered to the flow tube 100 by means of absorber adhesive 510. In yet another embodiment, as Figure 15 As shown, the absorber sheath 500 is adhered to the flow tube 100 by inserting a molded absorber sheath around the flow tube 100. The absorber adhesive 510 may be acoustically transparent. In some embodiments, it is preferred that the absorber adhesive 510 forms a flexible bond with the flow tube 100. In other embodiments, it is preferred that the absorber adhesive 510 forms a rigid bond with the flow tube 100. In some examples, the absorber adhesive 510 may be an adhesive similar to or the same as the transducer adhesive 156.

[0116] The absorber material can be any polymer or elastomer, such as polyvinyl chloride, silicone rubber, and the like. In one embodiment, the absorber material can be inherently flexible and have a lower stiffness than the flow tube. By providing an absorber with a stiffness different from and lower than that of the flow tube, vibrations are contained within the absorber rather than transmitted into the flow tube. At the interface between the absorber and the flow tube is a boundary, and the behavior of energy at the boundary inherently has two available factors: reflection and transmission / refraction. Reflected and transmitted waves will obey Snell's law.

[0117] Continue to refer to Figure 15 Preferably, fitting adhesive 186 is used to bond the flow tube 100 to end fittings 185, such as inlet fittings 180 and outlet fittings 190. Fitting adhesive 186 is configured to minimize energy transfer across the fitting tube transmission region 158 from transducers 155, such as piezoelectric elements 150, 151, as indicated by arrow T1. In some configurations, energy from transducers 155 is not transferred across the fitting tube transmission region 158. Fitting adhesive 186 inhibits energy transfer across the fitting tube interface region 158 and maximizes losses at the fitting tube transmission region 158. Preferably, fitting adhesive 186 inhibits out-of-phase and / or poor-quality vibrations generated in the end fittings 180, 190 by transferring acoustic energy between the first and second piezoelectric elements 150 and the end fittings 151. Preferably, fitting adhesive 186 is a low-viscosity medical-grade adhesive capable of flowing into the filling gap via capillary action, but other adhesives are also contemplated. In the fitting tube transmission area 158, it is desirable to have an air gap between the outer diameter and the flow tube 100 and the end fittings 180, 190, as this can reduce or prevent out-of-phase and / or poor energy transmission that may interfere with the main signal to be detected by the microprocessor.

[0118] However, regardless of the configuration of the fitting tube transfer area 158, it is desirable that the sidewall 111 of the flow tube 100 has minimal contact with the end fittings 180, 190. Instead, it is desirable that the end face 113 of the flow tube 100 is configured to contact the end receiving face 117 of each of the end fittings 180, 190, because maximum energy transfer occurs across the end face transfer area T2 from the end face 113 to the end receiving face 117. During assembly, this is achieved by applying a longitudinal biasing force to the flow tube 100 in the direction toward the end fittings 180, 190, because the fitting adhesive 186 permanently bonds the flow tube 100 and the end fittings 180, 190. Preferably, the fitting adhesive 186 maintains its desired properties after sterilization.

[0119] In one embodiment, it is desirable for the fitting adhesive 186 to attenuate acoustic coupling by filling the cavity between the flow tube 100 and the end fitting 185 through capillary action that provides a lower flexural modulus. Previous attempts to minimize energy transfer have involved the use of conventional O-rings; however, O-rings cannot be used in gaps smaller than 0.005”, such as the current gap between the flow tube 100 and the end fitting 185.

[0120] To optimize capillary transport of the fitting adhesive 186, fitting 185 (e.g., either or both of inlet fitting 180 or outlet fitting 190) may define an orifice having a conical internal profile and an adjacent shoulder having matching dimensions and orientation to match the end of the flow tube 100 received therein.

[0121] Specific reference Figure 15 , Figure 16 and Figure 18 The inlet fitting 180 has a distal orifice 171 adapted to receive a proximal portion of the flow tube 100 therein. The distal orifice 171 defines an inverted conical or conical orifice 172 having an adjacent shoulder 175. Both the distal orifice 171 and the adjacent shoulder 175 have matching dimensions and orientations to match the end of the flow tube 100 that can be received therein. The conical orifice 172 is sized to allow either end of the flow tube to be inserted therein such that the distal orifice 171 of the inlet fitting 180 is coaxial and concentric with the lumen of the flow tube 100, and such that the end of the flow tube 100 abuts the adjacent shoulder 175. The inverted conical or conical orifice 172 has a distal conical section 174 designed to allow capillary action during assembly to draw fitting adhesive 186 into the gap between the exterior of the flow tube 100 and the inner surface of the conical orifice 172. In one embodiment, the conical orifice 172 includes a proximal conical segment 177 that creates a gap between the outer surfaces of the flow tube 100 proximal to the distal end, the gap being unfilled by the fitting adhesive 186 and providing an air gap, such as... Figure 15 As shown in the diagram. The distal orifice 171 may be tapered and terminates at an end opposite to the adjacent shoulder 175 to engage the lumen of the flow tube 100. The distal orifice 171 of the inlet fitting 180 may be tapered and terminates at an end opposite to the adjacent shoulder 175 to engage a Luer-type fitting. In some embodiments, the distal orifice 171 is conical. In other embodiments, the distal orifice is inverted conical. In some embodiments, the distal orifice 171 comprises a two-part tapered section having an intermediate shoulder 173 between the proximal tapered section 177 and the distal tapered section 174. In other embodiments, the intermediate shoulder 173 is disposed approximately halfway along the length of the distal orifice 171. In another embodiment, the tapering between the intermediate shoulder 173 and the adjacent shoulder 175 ensures that when the tube 100 is press-fitted into the cavity, there is minimal or no air in the cavity, and the tube 100 does not contact the adjacent shoulder 175.

[0122] Specific reference Figure 15 , Figure 17 and Figure 19 The outlet fitting 190 has a proximal orifice 191 adapted to receive a distal portion of the flow tube 100 therein. The proximal orifice 191 defines an inverted conical or conical orifice 197 having an adjacent shoulder 195. Both the proximal orifice 191 and the adjacent shoulder 195 have matching dimensions and orientations to match the end of the flow tube 100 that can be received therein. The conical orifice 197 is sized to allow either end of the flow tube to be inserted therein such that the proximal orifice 191 of the outlet fitting 190 is coaxial and concentric with the lumen of the flow tube 100, and such that the end of the flow tube 100 abuts the adjacent shoulder 195. The inverted conical or conical orifice 197 has a proximal conical section 194 designed to allow capillary action during assembly to draw fitting adhesive 186 into the gap between the exterior of the flow tube 100 and the inner surface of the conical orifice 197. In one embodiment, the conical orifice 197 includes a distal conical segment 192 that creates a gap between the outer surfaces of the flow tube 100 distal to the proximal end. This gap is not filled with fitting adhesive 186 and provides an air gap, such as... Figure 15As shown in the diagram. The proximal orifice 191 may be tapered and terminates at an end opposite to the adjacent shoulder 195 to engage the lumen of the flow tube 100. In some embodiments, the proximal orifice 191 is conical. In other embodiments, the proximal orifice 191 is an inverted cone. In some embodiments, the proximal orifice 191 comprises a two-part tapered section having an intermediate shoulder 193 between the proximal tapered section 194 and the distal tapered section 192. In other embodiments, the intermediate shoulder 193 is disposed approximately halfway along the length of the proximal orifice 191. In yet another embodiment, the tapering between the intermediate shoulder 193 and the adjacent shoulder 195 such that the tube 100 is press-fitted with minimal or no air in the cavity and that the tube 100 does not contact the surface 195.

[0123] As by Figures 20A to 20D As shown in the process, end fittings 180, 190 can be adhered to flow tube 100 using fitting adhesive 186. For inlet fitting 180, the fitting adhesive is drawn into the distal tapered section 174 by capillary action. For outlet fitting 190, the fitting adhesive is drawn into the proximal tapered section 194 by capillary action. In one embodiment, end fittings 180, 190 can be adhered to flow tube 100 before being adhered to or otherwise attached to absorber sheath 500.

[0124] In another embodiment, as in Figures 21A to 21D As shown, the absorber sheath 500 can be adhered to the flow tube 100 using absorber adhesive 510. The absorber adhesive 510 can be sound-permeable. In some embodiments, it is preferred that the absorber adhesive 510 forms a flexible bond with the flow tube 100. In other embodiments, it is preferred that the absorber adhesive 510 forms a rigid bond with the flow tube 100. In some examples, the absorber adhesive 510 can be an adhesive similar to or the same as fitting adhesive 186 or transducer adhesive 156. Figures 21A to 21D As shown in the process, before the end fittings 180, 190 are adhered to the flow tube 100, the absorber sheath 500 can be adhered to the flow tube 100 with absorber adhesive 510.

[0125] Although this disclosure has been described as having exemplary designs, further modifications can be made to this disclosure within its spirit and scope. Therefore, this application is intended to cover any variations, uses, or adaptations of this disclosure that utilize the overall principles of the invention. Furthermore, this application is intended to cover derivatives based on this disclosure that fall within the scope of known or customary practice in the art to which this disclosure pertains and which fall within the limits of the appended claims.

Claims

1. A flow sensor subassembly for sensing the flow of a fluid pharmaceutical agent, the flow sensor subassembly comprising: A flow tube assembly through which the drug flows, the flow tube assembly having: A flow tube, the flow tube having a cavity, an outer diameter, a first end, and a second end; An inlet fitting having a conical orifice with an adjacent shoulder, wherein the conical orifice is sized for insertion into either end of the flow tube; as well as An outlet fitting having a conical orifice with an adjacent shoulder, wherein the conical orifice is sized for insertion into either end of the flow tube; as well as A first transducer is arranged at the inlet fitting; and The second transducer is located at the outlet fitting. The conical orifice of the inlet fitting and the outlet fitting is a two-part cone with a central shoulder approximately halfway along the length of the cone. The conical orifice of the inlet fitting includes a proximal conical section that creates a gap between the outer surfaces of the flow tubes proximal to the distal end. During assembly, the gap created by the proximal conical section between the outer surfaces of the flow tubes proximal to the distal end is not filled with fitting adhesive and provides an air gap. Similarly, the conical orifice of the outlet fitting includes a distal conical section that creates a gap between the outer surfaces of the flow tubes distal to the proximal end. During assembly, the gap created by the distal conical section between the outer surfaces of the flow tubes distal to the proximal end is not filled with fitting adhesive and provides an air gap.

2. The flow sensor sub-assembly according to claim 1, wherein, The first transducer is a first piezoelectric element, and the second transducer is a second piezoelectric element.

3. The flow sensor subassembly according to claim 1, further comprising an absorber sheath surrounding the flow tube, wherein, The absorber sheath is made of a different material than the flow tube.

4. The flow sensor sub-assembly according to claim 3, wherein, The absorber sheath is thermally shrunk to the outer diameter of the flow tube.

5. The flow sensor sub-assembly according to claim 3, wherein, The absorber sheath adheres to the flow tube.

6. The flow sensor sub-assembly according to claim 1, wherein, The first transducer and the second transducer have an annular shape and surround each corresponding fitting at each corresponding mounting point.

7. The flow sensor sub-assembly according to claim 1, wherein, The flow tube assembly is housed within a flow sensor housing having circuitry that engages with the first and second transducers. The flow sensor housing is coupled to a flow sensor base containing a microprocessor, and the circuitry includes connecting pins for providing electrical signals from the flow sensor subassembly to the microprocessor within the flow sensor base. The flow sensor subassembly is discarded after being used to sense the flow of at least one fluid agent, and the flow sensor base is used with different flow sensor subassemblies.

8. A method for assembling a flow sensor sub-assembly for sensing the flow of a fluid pharmaceutical agent, the method comprising: A flow tube is provided, the flow tube having a lumen, an outer diameter, a first end, and a second end; An inlet fitting is provided having a conical orifice with an adjacent shoulder, wherein the conical orifice of the inlet fitting is a two-part cone having a middle shoulder at approximately half the length of the cone; Insert the end of the flow tube into the conical orifice of the inlet fitting; A fitting adhesive is applied in the gap between the outer diameter of the flow tube and the inner diameter of the conical orifice of the inlet fitting, wherein the conical orifice of the inlet fitting includes a proximal conical section that creates a gap between the outer surfaces of the flow tube proximal to the distal end, and the gap created by the proximal conical section between the outer surfaces of the flow tube proximal to the distal end is not filled with fitting adhesive and provides an air gap; An export fitting is provided having a conical orifice with a shoulder, wherein the conical orifice of the export fitting is a two-part cone having a middle shoulder at approximately half the length of the cone; Insert the opposite ends of the flow tube into the conical orifice of the outlet fitting; A fitting adhesive is applied in the gap between the outer diameter of the flow tube and the inner diameter of the conical orifice of the outlet fitting, wherein the conical orifice of the outlet fitting includes a distal conical section that creates a gap between the outer surfaces of the flow tube distal to the proximal end, and the gap created by the distal conical section between the outer surfaces of the flow tube distal to the proximal end is not filled with fitting adhesive and provides an air gap. The first transducer is integrated into the inlet fitting; as well as The second transducer is integrated into the outlet fitting.

9. The method according to claim 8, further comprising the following step: The flow tube is inserted into an absorber sleeve surrounding the flow tube, wherein the absorber sleeve is made of a different material than the flow tube.

10. The method of claim 8, further comprising the step of: Insert the flow tube into the absorber sleeve surrounding the flow tube; as well as The absorber sheath is heated to shrink it to the outer diameter of the flow tube.

11. The method according to claim 9, wherein, The absorber sheath adheres to the flow tube.

12. The method according to claim 10, wherein, The absorber sheath adheres to the flow tube.

13. The method of claim 8, further comprising the step of: Insert the inlet fitting into the opening of the first transducer; as well as Insert the outlet fitting into the opening of the second transducer.

14. The method of claim 8, further comprising the step of: The flexible tubing is attached to the opposite ends of the internal passage of the inlet fitting or the outlet fitting.

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